Reference: Status: ŤStatusť

ID: 2330 Date Recvd: 2/27/97 Status: Closed

Reference:

All SRDs - V2 Paragraph 3.2.4

Physical and Interface Characteristics, Data Rates

For example the current text in the VIIRS SRD reads as follows:

"SRDV3.2.4-4

The data rate (orbit average) of the VIIRS sensor shall be less than or equal to the following limits:..."

Recommendation:

It is not clear whether the data rates specified in the SRDs refer to the raw sensor suite data rates or the rates after data compression is applied.

We recommend that the post compression data rates be clearly specified.

Rationale:

It is important to know the post compression data rates since they impact the sizing of the spacecraft C&DH subsystem elements such as the data bus bandwidth requirements and the size of the solid state recorder. The post compression data rates also impact the stored data downlink rates, especially given the requirement for downlinking data from a missed communications pass on the next available ground contact.

Response:

The data rates specified refer to the output of the sensor to the spacecraft. Data compression, if utilized, is applied by the sensor, not the spacecraft. Therefore, the specified data rates should be interpreted as post-compression data rates, assuming data compression is applied by the sensor. These data rates are the appropriate values for sizing the data bus bandwidth, solid state recorder, downlink rates, etc.

------------------------------------------------------------------ID: 2331 Date Recvd: 2/27/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph 3.2.4.0.5 Sensor Spacecraft Location

Recommendation:

Sensor Spacecraft Mounting Location The current text reads as follows:

"The CMIS notional baseline provides for the CMIS to be mounted on the zenith surface of the NPOESS spacecraft. Alternative mounting locations will be considered by the NPOESS Program, but approval of alternative locations will be at the discretion of the NPOESS Integrated Program Office.

SRDC3.2.4.0.5-1

The CMIS contractor shall formally request a mounting location."We recommend deleting this paragraph in its entirety for the following reasons:

No corresponding mounting paragraphs are included in the other SRDs; we see no reason to treat CMIS any differently

Candidate mounting locations for all sensors should be a consideration for the Pre-TSPR contractors -- and the eventual TSPR contractor -- working in concert with the selected sensor providers and considering the payload as a whole, vs. each sensor individually

Zenith mounting of the CMIS antenna assembly is only one alternative, and may not be optimum for all spacecraft options

Rationale:

It may be desirable to maintain flexibility in the specific details of sensor accommodation to allow the Pre-TSPR/TSPR contractor(s) to perform trade studies in conjunction with the sensor suppliers to determine the optimum configuration for mounting the entire payload on the NPOESS spacecraft.

Response:

The SRD has been revised to emphasize that the CMIS zenith mounting location is (TBR), and a statement included which says "Alternative mounting locations will be considered by the NPOESS Program, but will not be approved until satisfactory accommodation of other sensors on the spacecraft has been demonstrated."

------------------------------------------------------------------ID: 2332 Date Recvd: 2/27/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph 3.2.1.1 Performance Requirements

Table of Attributes for Cloud Base Height EDR (App D Section 40.4.1)

Recommendation:

It appears that the table of attributes for the Cloud Base Height EDR is missing in the SRD. We recommend the insertion of the appropriate table.

Rationale:

Completeness of requirements and consistency with the other CMIS EDRs.

Response:

Thank you for bringing to our attention the omission of the Cloud Base Height EDR table. The appropriate table has been inserted into the CMIS SRD.

------------------------------------------------------------------ID: 2333 Date Recvd: 2/27/97 Status: Closed

Reference:

GPSOS SRD -V2 Paragraph 3.2.1.1.3.1.1 Electron Density Profiles/Ionospheric Specification

The measurement range and measurement uncertainty values for "1. Density at an arbitrary altitude below NPOESS" in the EDR attribute table are incorrect for the data product.

Recommendation:

The current text in the table reads as follows:

G40.8.5-9 1. g. Measurement Range - Density at an arbitrary altitude below NPOESS (local density) Reads = greater of 20% or 3x105-107 cm-3, and greater of 20% or 104cm-3

G40.8.5-12. h. Measurement Uncertainty - Density at an arbitrary altitude below NPOESS (local density) Reads = 3 x105 cm-3 (TBR), and 104 cm-3

Recommend change to:

G40.8.5-9 1. g. Measurement Range - Density at an arbitrary altitude below NPOESS (local density) Reads = 3x105-107 cm-3, and 104-107 cm-3

G40.8.5-12. h. Measurement Uncertainty - Density at an arbitrary altitude below NPOESS (local density) Reads = greater of 20% or 3 x105 cm-3 (TBR), and greater of 5% or 104 cm-3

Rationale:

The values in the table of the SRD are not consistent with the definition of measurement range. The recommended values are consistent with TRD Appendix D, Section 40.8.5.

Response:

The discrepancy has been corrected. The table has also been significantly revised. Please see final RFP SRD.

------------------------------------------------------------------ID: 2334 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) -V2 Paragraph 3.2.1.1.5.1, page 35

Processing speed

Recommendation:

The instrument contractor shall deliver algorithms compatible with the 20 minute processing time at the Centrals or the field terminals. It seems that there should be some indication of the processing speed at the ground stations (anticipated in year of IOC) so the contractor knows what he has to interface to, a Cray or a PC Jr. This is a critical interface issue between payload providers and system houses.

Rationale:

Recommend removal of this requirement from SRDs making it a system only requirement (via TRD), or a detailed specification of the processing hardware on which the algorithms would be benchmarked.

Response:

This requirement must be levied on the sensor contractor because it is a limitation on the complexity of the scientific algorithms which can be provided by the sensor contractor to verify that EDR requirements can be met. We agree that some benchmark for processing speed is necessary to make this requirement meaningful. Benchmarking current processing capabilities at the Centrals and field terminals might be unnecessarily restrictive given anticipated imporvements, but future capbilities are not yet known. The requirement can be further quantified during Phase 1.

------------------------------------------------------------------ID: 2335 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.3.6-9, page 20

Total Water Content Measurement Uncertainty - Global Average

Recommendation:

Previous versions of the TRD and SRD had the Threshold Measurement Uncertainty Global Average (for Total Integrated Water Vapor [TIWV]) of 1 kg/m2. The value of .2 kg/m2 was reserved for Cloud Liquid Water Content over the Ocean. Since there is now no division between the two, TIWV is the dominat factor and the EDR Measurement Uncertainty should reflect the uncertainty of the most dominant phenomena. In addition, the latest TRD has 1 kg/m2 for global average.

Rationale:

Recommend change to "1 kg/m2 ".

Response:

Accept.

------------------------------------------------------------------ID: 2336 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.4.4-3, page 21

Cloud Ice Water Path Threshold Vertical Cell Size

Recommendation:

The threshold Vertical Cell Size has "(Vertical Reporting Interval)" with no data in the block for "Vertical Reporting Interval". Previous versions of the SRD and TRD had "15 km (Total Column)". This would correspond with what is in the Vertical Reporting Interval block of "N/A (Total Column)"

Rationale:

Recommend change to "15 km (Total Column)".

Response:

Thank you for bring this omission to our attention. The correct entry of "15 Km (Total Column) has been inserted into the EDR Table.

------------------------------------------------------------------ID: 2337 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraphs C40.2.3-12, C40.2.6-13, C40.3.3-7, C40.3.4-9, C40.4.4-11, C40.40.7.2-9, C40.7.3-6, C40.7.8-8

Mapping Uncertainty

Recommendation:

The first draft SRD had a correction which made all the mapping uncertainties 5 km. The above paragraphs have the mapping uncertainty of 3 km (except for C40.4.4-11 which is 4 km), which was the value given before the correction. If the IPO still intends to make the mapping uncertainties consistent, then 5 km is reasonable.

Rationale:

Recommend change the Mapping Uncertainties to 5 km for the above paragraphs.

Response:

The mapping uncertainties were changed back to the IORD/TRD values since these are what were requested by different users for different purposes. If it can be shown that the user doesn't need this accuracy or that it is an unacceptable cost driver than we will reconsider changing the value.

------------------------------------------------------------------ID: 2338 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD TRD - V2 Paragraph C40.3.6-3, page 20 | Paragraph 40.3.6-3, page D-21

Total Water Content Threshold Vertical Cell Size

Recommendation:

Previous versions of the TRD and SRD had the Threshold Vertical Cell Size stated as "Total Column". The other two EDRs which are included in this EDR, 40.4.4 (Cloud Ice Water Path) and 40.4.5 (Cloud Liquid Water) still have "Total Column" for the threshold requirement. If this is not a typo, but the IPO intends this to be a profile at threshold, this will be a critical modification to this EDR and may be a performance driver for the threshold instrument.

Rationale:

Recommend "Total Column" replace these paragraphs.

Response:

The TRD removes the discrepancy of defining components in terms of total coumn measurements because the IORD specifies that this EDR shall be in vertical increments. Agree that this could be a performance driver. The issue is being raised to the JARG. Note that the value is TBR for further analysis and coordination.

------------------------------------------------------------------ID: 2339 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.2.4.10 Measurement Accuracy; Sea Surface Temperature: 0.2 K

Recommendation:

Relax this EDR requirement to 0.3 to 0.5 K.

Rationale:

Measurement accuracy is affected by required atmospheric corrections and cannot be reduced much below 0.3 to 0.5 K even if the instrument has no errors associated with it. Additional narrow bands in the visible may be required for atmospheric screening, although the ocean bands might be able to fulfill this role.

Response:

Disagree. It may be difficult to reduce the measurement uncertainty much below 0.3 to 0.5 K in the absence of sensor errors, but we believe the bias associated with current operational SST algorithms is almost negligible (of the order of milliKelvin). Since the accuracy is defined as the bias in a set of measurements, I.e., the difference between the true value and the mean, the government sees no need to relax this requirement based on algorithmic performance.

------------------------------------------------------------------ID: 2340 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.2.6.11 Uncertainty, clear sky; Soil Moisture: 20 cm/m

Recommendation:

1) Make CMIS the primary sensor for this EDR, with VIIRS playing a supplementary role.

2) Let VIIRS supplement CMIS by providing a wetness index under clear skies only.

Rationale:

Electro-optical sensors, such as NPOESS, can provide qualitative measures of soil wetness, but cannot provide quantitative measures to a 20% accuracy. This EDR more appropriately belongs to a microwave sensor which can provide quantitative measurements.

Response:

The VIIRS is primary for this EDR under clear conditions, and the CMIS is primary for this EDR under cloudy conditions. CMIS cannot be made primary for this EDR under clear conditions because the horizontal cell size requirement under clear conditions cannot be met by a practical microwave sensor. The measurement uncertainty requirements are TBR. Therefore, if it becomes clear in the course of the VIIRS development contract that the measurement uncertainty requirement cannot be met by the VIIRS under clear conditions, it may be revised.

------------------------------------------------------------------ID: 2341 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.2.6.12 Uncertainty, cloudy sky; Soil Moisture: 10 cm/m

Recommendation:

Re-assign this portion of the EDR to a microwave sensor such as CMIS.

Rationale:

VIIRS cannot provide soil moisture estimates under cloudy skies.

Response:

VIIRS is not responsible for soil moisture under cloudy conditions. VIIRS is only responsible for EDR attributes that are numbered as requirements, and the measurement uncertainty under cloudy conditions is not numbered. A statement has been added to the VIIRS SRD to make this clear.

------------------------------------------------------------------ID: 2342 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.3.1.11 Accuracy; Aerosol Optical Thickness: 0.03 over ocean

Recommendation:

Relax this EDR requirement for high optical depths (i.e., > 0.30).

Rationale:

MODIS can obtain a 0.03 accuracy over oceans for small optical depths. For optical depths greater than 0.3, the accuracy is only 10 to 20% of its value, or from 0.03 to about 0.2. Substantial regions of the Atlantic Ocean and the Arabian Sea, for example, will have high aerosol optical depths where a 0.03 accuracy cannot be obtained with VIIRS.

Response:

A TBR has been inserted on the optical depth to allow further investigation. If in the course of the VIIRS contract it becomes clear that satisfaction of the 0.03 measurement accuracy requirement is not feasible at higher optical depths, then relaxation of this requirement may be considered.

Note also that, the contractor is to specify any conditions under which the requirement to deliver an EDR meeting data content and quality requirements will not be met.

------------------------------------------------------------------ID: 2343 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.3.1.1 Horizontal cell size; Aerosol Optical Thickness: 10 km

Recommendation:

Relax the EDR spatial resolution to 50 km over land, which is achievable with current algorithms.

Rationale:

AVHRR currently publishes AOT at a 100 km resolution. MODIS has a 50 km resolution over land and 5 km resolution over oceans. EOSP has a 40 km resolution. Over land, VIIRS will achieve a 10 km resolution only if present day algorithms are enhanced, which might be a cost driver.

Response:

If in the course of the VIIRS contract it becomes clear that this requirement is in fact a cost driver, relaxation of the requirement may be considered at that time. It would be premature at this time to relax the requirement before the necessary algorithm development and sensor impacts have been addressed. Note that the measurement accuracy requirement could be stressing at the required HCS and that parameter is already annotated with a TBR.

------------------------------------------------------------------ID: 2344 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.3.1.2.11 Accuracy; Aerosol Particle Size Parameter: 0.3 over ocean

Recommendation:

Relax this EDR requirement for low aerosol optical depths (i.e., for tau below about 0.10).

Rationale:

For low aerosol amounts, the reflectance signal becomes small at all wavelengths. Under these conditions, distinguishing the aerosol particle size distribution becomes increasingly uncertain and a 0.3 accuracy may not be obtainable.

Response:

If in the course of the VIIRS contract it becomes clear that this requirement cannot be satisfied, then relaxation of the requirement may be considered. Note also that the SRD requires that the contractor specify any conditions for which EDR requirements are not met (SRDV3.2.1.1.1-5).

------------------------------------------------------------------ID: 2345 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.4.3.4 Vertical reporting interval; Cloud Effective Particle Size: 1.0 km

Recommendation:

Delete the EDR requirement to have profiles of Cloud Effective Particle Size.

Rationale:

Cloud effective particle size can only be obtained for the upper layers of thick clouds and for the mean of thin clouds. It cannot be resolved vertically.

Response:

Agree. The vertical reporting interval requirement is TBR.

------------------------------------------------------------------ID: 2346 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.6.3.4 Snow depth ranges; Snow Cover/Depth: > 0 cm (any snow thickness)

Recommendation:

Re-assign snow depth to CMIS.

Rationale:

Electro-optical instruments like VIIRS cannot derive snow depth. This portion of the EDR belongs to a microwave sensor, which can sense snow moisture and depth, except for the case of dry snow which is less than 5 cm thick.

Response:

The threshold requirement is to estimate snow cover regardless of depth. The government believes that this threshold requirement is within the capability of an electro-optical instrument.

Note that the attributes for cloudy conditions for this EDR appeared incorrectly as numbered requirements for the VIIRS in the version of the document reviewed by the commentator. This has been corrected.

------------------------------------------------------------------ID: 2347 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.7.4.5 Accuracy; Littoral Sediment Transport: Greater of 30% and TBD

Recommendation:

Relax this EDR requirement to 50%.

Rationale:

MODIS, using 9 ocean color bands, is not willing to claim better than 50% accuracy for chlorophyll.

Response:

If in the course of the VIIRS contract it becomes clear that this requirement cannot be satisfied, then relaxation of the requirement may be considered.

(It is assumed that the 50% accuracy in the rationale applies to littoral sediment transport, not chlorophyll.)

------------------------------------------------------------------ID: 2348 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.7.5.5 Accuracy; Net Heat Flux (over oceans): 10 W/m2

Recommendation:

Assign this EDR to the Earth Radiation Budget instrument

Rationale:

Calculating net heat flux is a complex task. For the 20 km spatial resolution sought for NPOESS, a radiation budget instrument is more suitable, such as CERES. CERES calculates the net heat flux to an accuracy of 20 W/m2 at the 25 km resolution. MODIS will not measure net heat flux. Several algorithms have used combined AVHRR and SSM/I data to get heat flux on a monthly time scale and at a 1 degree spatial scale, but these algorithms do not satisfy the NPOESS requirements.

Achieving 10 W/m2 at the 25 km resolution is challenging as a threshold; anything near 1 W/m2 is not achievable.

Response:

Also, the CERES instrument is only being flown in th 1300 hundred orbit in the notional system baseline and would not allow and would not meet the six hour refresh required by DoD Naval operations. It is also not clear that CERES can meet all of the parameters.

------------------------------------------------------------------ID: 2349 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.7.6.6 Accuracy; Ocean Color/Chlorophyll: The > of 30% or TBD mg/m3

Recommendation:

Relax this EDR requirement to 35%.

Rationale:

MODIS, using 9 ocean color bands, is not willing to claim better than 35% accuracy for chlorophyll.

Response:

If in the course of the VIIRS contract it becomes clear that this requirement cannot be satisfied, then relaxation of the requirement may be considered.

------------------------------------------------------------------ID: 2350 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.7.2.1 Horizontal Cell Size, Fresh Water Ice: 0.4 km

Recommendation:

Consider reducing the HSR for this EDR.

Rationale:

The HSR for this data product exceeds those of most other VIIRS data products. It is likely to require several high spatial resolution bands and hence will drive up data processing and data storage for the program. Instrument construction and design costs may also be significantly impacted.

Response:

The horizontal cell size for this EDR refers to underlying imagery used to estimate the ice edge boundaries and concentration, not to the cells for which ice concentration must be estimated to the nearest 1/10. The EDR requirement will be modified to make this clear.

------------------------------------------------------------------ID: 2351 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD (Version 2, 18 Feb 97) - V2 Paragraph 3.2.4.6

Endurance

Recommendation:

"Design service life of the satellite shall be at least 154 years." I suspect this number is a typo.

Rationale:

Unreasonable number.

Response:

Typo corrected (15 yrs).

------------------------------------------------------------------ID: 2352 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD - V2 Appendix A

Definitions

Recommendation:

Appendix A of the SRD provides definitions of the terms accuracy, precision, and uncertainty. The definitions in Appendix A could be improved to avoid becoming unintentional cost drivers. Based upon a review of the definitions of these terms by Hughes and government scientists, and by a comparison of these definitions to those used by the EOS Calibration Advisory Panel, the International Standards Organization (ISO), and the National Institute of Standards and Technology, the following definitions for these terms were drafted:

Accuracy

Each geophysical parameter or EDR has a true value at each spatial and temporal point. Each EDR will have a measured value as well. Both the measured and true values are expressed in terms of SI units or the fundamental units of nature maintained by NIST and other standards organizations. The difference between the measured value and true value is the error.

The accuracy is the probability that the error is less than a specified number. For example, the accuracy can be defined as the 95% probability that the error of each individual measured value is less than a specified number. 95% gives a two standard deviation or two-sigma bound on a group of measurements assuming they follow a Gaussian distribution.

Two sigma limits are specified above. Accuracy can be defined in terms of one, two, or three sigmas. It is important that the number of sigmas used to specify accuracy be clearly stated.

As an example of the above definition, a 0.1 K accuracy is sought at a 0.1 km spatial resolution for Sea Surface Temperature. This means that each 0.1 km region will have its measured SST within 0.1 K of the true SST for at least 95% of the measurements. For NPOESS, the SST's must be determined with this accuracy within about 2 hours of initial collection of the raw data.

Precision

Precision is a measure of the repeatability of the measurements, usually for a set of measurements made over a relatively short time interval. A measurement can be precise without being accurate. Precision can be expressed as the two-sigma limits on the measurement, which gives the 95% confidence that the group of measurements are giving an internally self-consistent result.

Stability

Stability is the internal self-consistency or repeatability of the measurements over long time intervals. Stability can be expressed in terms of accuracy, with the ability to maintain the accuracy being a measure of stability. The stability can be expressed as the two-sigma estimate on the accuracy measurements at one time compared to the two-sigma estimate of accuracy at a different time. The standard deviations of the accuracy are not necessarily constant in time in this definition. If the measurements are accurate within the two-sigma estimates of the accuracy at these two times, the measurements can be defined as stable.

Uncertainty

Uncertainty is the sum of the accuracy and the precision, because accuracy and precision can be considered as independent quantities.

Comments:

The above definitions are precise and provide quantitative techniques for the instrument vendors and algorithm development teams to determine if the EDR specifications for accuracy, precision, stability, and uncertainty are being met.

Additional Sentence by Sentence Commentary

Based upon these new definitions, the following sentence by sentence comments are made on the IPO definitions of these terms.

Measurement Accuracy

The magnitude of the differences between the mean value of a measurement or derived parameter and its true value.

COMMENT: This sentence gives the definition for the error, not accuracy, as the IPO recognizes from its own sentence: "'Error' is defined as the difference between the measured or derived value and the true value of the parameter." Error is the true difference between the measurement and the true value. It is unknown. Its probablisticly estimated value is called the accuracy.

The mean value is based upon a representative ensemble of measurements for which the true value of the parameter is approximately the same and for which the number of measurements is large enough so that the sample size error in the measurement accuracy is negligible compared to the specified measurement accuracy value.

COMMENT: The definition for accuracy is completely independent of sample size (ensemble). A single measurement has an accuracy associated with it. This sentence should not be part of any definition of accuracy. Furthermore, the phrase "sample size error in the measurement accuracy" implies the TRD is talking about precision here. This sentence is confusing precision with accuracy and should be clarified.

An ensemble of measurements is representative if the physical conditions occurring when the measurements are performed span the range of conditions which typically occur in nature and if these conditions have approximately the same relative frequency of occurrence within the ensemble as they do in nature.

COMMENT: Like the previous sentence, this sentence may be confusing precision with accuracy and would therefore be invalid in any definition of accuracy.

Measurement Precision

The standard deviation (one sigma) of a measured or derived parameter based on a representative ensemble of measurements for which the true value of the parameter is approximately the same and for which the number of measurements is large enough so that the sample size error in standard deviation is negligible compared to the specified measurement precision value.

COMMENT: Precision can be expressed as the one deviation spread of a group of independent measurements of a parameter. The sample size does not need to large or small - it is only important its size be known. Furthermore, measurements can be very precise yet be inaccurate. Therefore, there is no need to mention the true value in a definition of precision.

COMMENT: The sample size need only be known and does not have to have "same relative frequency of occurrence . . as they do in nature." This implies that an infinitely large sample is required to determine precision because sample sizes in nature are essentially infinite. This sentence should be removed from any definition of precision.

Comments:

Measurement Uncertainty

The RMS of the errors (one sigma) in a measured or derived parameter based on a representative ensemble of measurements for which the true value of a parameter is approximately the same and which is large enough so that the sample size error in the RMS value is negligible compared to the specified measurement uncertainty value.

COMMENT: The last sentence in the measurement uncertainty definition is all that is needed to define uncertainty. This sentence should be removed. Sample size does not need to be large - it only needs to be known.

"Error" is defined as the difference between the measured or derived value and the true value of the parameter.

COMMENT: This sentence is correct, but it belongs in the section on measurement accuracy.

COMMENT: The last sentence in the measurement uncertainty is all that is needed to define uncertainty. This sentence should be removed. Sample size does not need to be large - it only needs to be known.

As defined herein, measurement uncertainty is due to the combined effects of all systematic and random errors and is equal to the RSS of the measurement accuracy and the precision in the limit of infinitely large ensembles of measurements.

COMMENT: This sentence is nearly correct if the ending phrase "in the limit of infinitely large ensembles of measurements" is deleted. A simple sum of the precision and accuracy is sufficient to define the uncertainty. They are completely independent quantities so either an RMS or RSS combination is inappropriate.

In summary, it appears that the TRD definitions are currently at variance with the understanding of these terms by the scientific community.

Rationale:

The correct and unambigous definitions of accuracy, precision, uncertainty, and stability are important since they form the basis of instrument and experimental design. An incorrect or imprecise definition can cause cost increases by driving designs in unintended ways.

Response:

The definition of accuracy proposed is a variant of the TRD definition of uncertainty. Since the accuracy as so defined includes all errors, both random and systematic, it is not independent of the precision, which also includes random errors. Therefore, we disagree with the statement within the recommended definition of uncertainty that "accuracy and precision can be considered as independent quantities", based on the definitions in the comment. We also disagree with the suggested definition of uncertainty as the "sum of the accuracy and precision". Since both the accuracy and precision include random errors, combining them in any fashion would "double count" these errors.

Response to the "Additional Sentence by Sentence Commentary":

Measurement Accuracy

We disagree with the comment that the government definition identifies "error" with "accuracy". The government defines accuracy as the MEAN error. We agree that the error is a random variable, and that the accuracy should be defined statistically as an estimate of this random variable. However, the government defines this statistical estimate in terms of the mean, not the standard deviation or a multiple thereof, as the commentator proposes. The IORD clearly defines the accuracy in terms of systematic errors only, and therefore defining accuracy as a bias is consistent with the intent of the user community and presumably with the required values of the accuracy provided by the user community in the IORD.

Accuracy, like precision, uncertainty, and long-term stability, is defined by the government in terms of a large, but finite, statistical ensemble. The mean value of a random variable over a finite sample of the infinite universe of possible measurements is itself a random variable. The standard deviation of this finite sample mean (square root of the variance) over the infinite universal ensemble of possible measurements is the sample size error. This sample size error must be much smaller than the required value of accuracy for any simulation which purports to verify that the accuracy requirement is met.

Also, we disagree with the comment that a single measurement has an "accuracy" associated with it. A single measurement only has an "error" associated with it. The commentator's proposed definition of accuracy is statistical in nature, as is the government definition, and is therefore not meaningful for a single measurement.

Measurement Precision

The sample size must be large enough so that the standard deviation of the precision, which is a finite sample standard deviation, is negligible compared to the required value. We restrict the ensemble to one having a common true value because the precision must be satisfied for ANY true value of the measured parameter within the measurement range. Precision, as the government defines it, could have a functional dependence on the true value of the measured parameter.

The finite ensemble on which the definitions of precision, as well as accuracy, uncertainty, and long-term stability, are based must be representative of the universe of possible measurements. Environmental conditions that occur only rarely in nature should not not occur predominantly in the finite sample, since the statistical parameters that are estimated, whether the mean or the standard deviation, would be skewed away from what they will be in actual operations. Similarly, the environmental conditions represented in the finite ensemble must not only be typical--atypical conditions must also be represented in proportion to their frequency of occurrence in nature. To the extent that the statistical ensembles used in simulations approach this ideal of being representative of nature, the statistical results of the simulations will better predict the accuracy, precision, uncertainty, and long-term stability of the actual measurements in operation.

Measurement Uncertainty

We disagree with the commentator's statements regarding combining accuracy and precision for the reasons stated above.

Summary:

We agree that measurement accuracy and precision should be defined clearly and unambiguously, and have attempted to do so. We do not see a need to redefine accuracy in a manner that is inconsistent with the IORD, although we are aware that this term has usages in the scientific and user communities which differ from the one we have adopted for this program.

------------------------------------------------------------------ID: 2353 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraphs C40.2.2-25, C40.2.2-26, C40.2.2-30, page 14

Atmospheric Vertical Temperature Profile Key Attribute

Recommendation:

The previous versions of the SRD and TRD rendered these paragraphs in bold font to indicate that they are Key Attributes. These should be also.

Rationale:

Recommend these paragraphs be in bold font.

Response:

All references to key attributes are being deleted from the primary EDR section of each SRD to emphasize the government's intent that the sensor contractors address all primary EDR attribute thresholds assigned to their sensors.

------------------------------------------------------------------ID: 2354 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.2.4-9, page 16

Sea Surface Temperature Key Attribute

Recommendation:

The previous versions of the SRD and TRD rendered this paragraph in bold font to indicate that it is a Key Attribute. This should be also.

Rationale:

Recommend this paragraph be in bold font.

Response:

Please see comment #2353.

------------------------------------------------------------------ID: 2355 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.2.6-9, page 18

Soil Moisture Key Attribute

Recommendation:

The previous versions of the SRD and TRD rendered this paragraph in bold font to indicate that it is a Key Attribute. This should be also.

Rationale:

Recommend this paragraph be in bold font.

Response:

Please see comment #2353.

------------------------------------------------------------------ID: 2356 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.3.5-10, page 20

Pressure Profile Measurement Accuracy

Recommendation:

The heading "Measurement Accuracy" is missing in-between paragraphs C40.3.5-9 and C40.3.5-11.

Rationale:

Recommend "h. Measurement Accuracy" be inserted.

Response:

Thank you for bring this omission to our attention. The "Measurement Accuracy" heading has been inserted into the EDR Table.

------------------------------------------------------------------ID: 2357 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Paragraph C40.4.1-1 to C40.4.1-9, page 21

Cloud Base Height Requirements

Recommendation:

The requirements matrix is missing from this EDR.

Rationale:

Recommend insert requirements matrix, paragraphs C40.4.1-1 to -9.

Response:

Accept. The requirements matrix has been inserted.

------------------------------------------------------------------ID: 2358 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Secondary EDRs through Paragraph SRDC3.2.1.1.1.1-5, page 27

Secondary EDRs

Recommendation:

The referenced paragraph states "...the following Secondary EDRs..., but the associated EDRs requirements are before this paragraph. Moving this paragraph to before the Land Surface Temperature EDR would allow the information to flow correctly and would also correspond to the sequence in paragraph 3.1.1 on page 7.

Rationale:

Recommend move this paragraph to before EDR "Land Surface Temperature" and paragraph SRDC3.2.1.1.1.1-6 on page 26.

Response:

The CMIS SRD has been reworded to clarify the intent of the IPO regarding CMIS Secondary EDRs.

------------------------------------------------------------------ID: 2359 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Table 3.2.4.7.3.2, p. 66

Hot and Cold Environments

Recommendation:

Eliminate reference to BTU/hr-ft2. Use metric units instead.

Rationale:

See comment 020.

Response:

Corrected in the 3-17-97 version., Note that the value was provided in both English and metric for those that have trouble making the conversion.

------------------------------------------------------------------ID: 2360 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Paragraph 3.2.6.2.1.1-1, p76

Temperatures

Recommendation:

Maximum temperature excursion is cited in Fahrenheit degrees. Convert to equivalent Centigrade.

Rationale:

See comment 020.

Response:

Corrected in the 3-17-97 version.

------------------------------------------------------------------ID: 2361 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Figure 3.2.6.2.1.1, page 77

PLF Inner Temperatures chart

Recommendation:

Temperature is given in Fahrenheit. Convert figure to Centigrade.

Rationale:

See comment 020.

Response:

Corrected in the 3-17-97 version.

------------------------------------------------------------------ID: 2362 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Table 3.3.12.4.2, p. 93

Factors of safety for pressurized components

Recommendation:

No mention is made of composite overwrapped pressure vessels which offer significant savings in weight (and cost). Appropriate safety data is currently being obtained at Aerospace for the Cape flight safety people.

Rationale:

Recommend a TBD for such vessels be added.

Response:

Concur that composite overwrapped pressure vessels should not be excluded but note that the section in the 3-17-97 RFP has a TBR on it indicating that this section is under review and we are open to recommendations. We will check on what is being put together at Aerospace. The IPO is setting up an Interface Working Group to deal with such issues.

------------------------------------------------------------------ID: 2363 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Paragraph 4.2.4.1, p. 107

Finite Element Model

Recommendation:

Requirement states that a finite element model using NASTRAN be supplied. However, no specific version was indicated.

Rationale:

Recommend citing latest version of NASTRAN.

Response:

The government is able to use the finite element model generated by any recent versions of NASTRAN. Translation programs will be written to accommodate version changes. There is no requirement for the finite element model to use a specific version of NASTRAN nor even NASTRAN, although it is the industry standard. A NASTRAN-like model is acceptable.

------------------------------------------------------------------ID: 2364 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Paragraph 4.2.7.5

Acoustic Testing

Recommendation:

Surface-to-mass ratio cited in in2/lb. Convert to m2/kg.

Rationale:

See comment 020.

Response:

Units converted to cm2/kg.

------------------------------------------------------------------ID: 2365 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD (2/18/97 Version 2.0) - V2 Paragraph 3.2.4.2, p. 56

Dimensions

Recommendation:

Eliminate English units as an option or state that all measurements and calculations are performed in SI units.

Rationale:

Dual measurement use can only lead to problems.

Response:

English as an option has been deleted in the 3-17-97 versuib.

------------------------------------------------------------------ID: 2366 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.3.1.3.7 Type; Suspended Matter: dust, sand, ash, other

Recommendation:

Eliminate the requirement to routinely distinguish suspended matter types.

Rationale:

Dust, sand, and ash may have different size distributions and do have different absorption properties. However, there are no clear cut distinguishing properties that can be routinely identified under all observing conditions. This data product attribute might more appropriately be considered a research EDR or on-demand EDR rather than a routinely generated EDR.

Response:

The probability of correct typing for suspended matter is TBD. Also, the minimum amount of suspended matter required to be detected is not specified. Therefore, the difficulty in generating this EDR might ultimately be reflected in a low probability of correct typing under a broad range of conditions, or a somewhat higher probability of correct typing under more restricted conditions. These conditions may include the presence of large amounts of suspended matter, which should facilitate typing. In any case, the IORD states, "Detection of suspended dust, sand, volcanic ash as thresholds, and these plus sea salt detection as an objective", clearly indicating a user requirement for detection of dust, sand, and volcanic ash as a routine product.

------------------------------------------------------------------ID: 2367 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.5.2.5 Accuracy; Albedo: 0.05

Recommendation:

Set 0.05 as a goal that can be met in many cases, but realize that there will be a number of cases where this goal cannot be met.

Rationale:

MODIS and MISR combined are expected to obtain surface albedo accuracies in the visible with an accuracy between 0.014 and 0.142. This accuracy cannot be obtained within 2 hours, as required by NPOESS, but requires multiple looks at the same pixel over at least a 16 day interval. Furthermore, accuracy is very dependent on surface type and season.Ref.: Wanner, W. et al., 1997. Global retrieval of bidirectional reflectance and albedo over land from EOS MODIS and MISR data: Theory and algorithm. J. Geophys. Res. (in press).

Response:

The government expects the sensor contractor to report any limitations regarding the conditions under which a threshold can be met beyond the stipulated conditions of clear versus cloudy and day versus night. Based on the information provided by the sensor contractors, the government may elect to change a threshold value or restrict the conditions under which the threshold must be achieved.

Use of measurement data acquired over time intervals much longer than the two hour timeliness requirement is allowed as long as these data are used to generate an estimate for the value of an EDR parameter at a time which is no earlier than two hours before the EDR is delivered to the user, and as long as this estimate meets all other requirements. However, in order to meet the revisit and timeliness requirements, successive parameter estimates can only utilize a limited amount of new data, the duration of which is constrained by the revisit time requirement, and the processing required to generate these estimates must be compatible with a two hour timeliness requirement.

For example, albedo estimates may be based on a temporally sliding window 16 (or more) days in duration, as long as an estimate is generated frequently enough to satisfy the maximum local average revisit requirement and as long as the time for which each estimate is made is no earlier than two hours before the time at which the estimate is delivered to the user.

------------------------------------------------------------------ID: 2368 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.6.1.5 Accuracy; Land Surface Temperature: 2.5 K

Recommendation:

1) Relax this EDR requirement to 4 K under conditions where the surface emissivity cannot be determined well.2) Get Soil Moisture and Atmospheric Moisture from CMIS and CrIS as inputs to the VIIRS algorithm.

Rationale:

Measuring land surface temperatures is difficult. Atmospheric corrections for aerosols and water vapor are required along with a determination of surface emissivity. MODIS uses 13 channels to calculate this EDR and claims a 1 to 4 K accuracy dependent on location and scan angle. It may be difficult for VIIRS, with fewer channels, to exceed MODIS's accuracy, unless CMIS and CrIS inputs are allowed.

Response:

CMIS and CrIS inputs are allowed. It would be premature at this time to relax this requirement until the sensor contractors have addressed its feasibility.

------------------------------------------------------------------ID: 2369 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

40.6.4.6 Vegetation surface types; Vegetation Index/Surface Type: 21 types

Recommendation:

Use a combination of sensors (VIIRS, CMIS, CrIS) to derive surface types.

Rationale:

1) It may be difficult for VIIRS (with 13 channels) to distinguish 21 surface types. AVHRR can distinguish 14 types. The USGS uses 27 surface types, the IGBP uses 17 types, and the Simple Biosphere Model uses 20 types. There is no scientific consensus yet on the number of surface types. This subject requires further study, before it becomes a major instrument cost driver.2) Loam, clay, and sandy soil all have very similar reflectances. Distinguishing between them may require 5 to 10 near IR bands and could drive the cost of VIIRS up significantly.3) The same statement applies to gravel and rocky fields.4) MODIS plans to distinguish 36 surface types, but the algorithms use nearly all of the 36 channels, are time consuming, and may require several months of compositing to get answers. From the VIIRS specifications, it appears they want surface types within 2 hours of data acquisition right from the start of the experiment. If this requirement is not clarified, it could drive costs.

Response:

Use of multiple sensors is allowed for generation of this or any other EDR.

Use of measurement data acquired over time intervals much longer than the two hour timeliness requirement is allowed as long as these data are used to generate an estimate for the value of an EDR parameter at a time which is no earlier than two hours before the EDR is delivered to the user, and as long as this estimate meets all other requirements. Compositing data over many months to generate the first land type estimate is acceptable. However, in order to meet the revisit and timeliness requirements, successive land type estimates can only utilize a limited amount of new data, the duration of which is constrained by the revisit time requirement, and the processing required to generate these estimates must be compatible with a two hour timeliness requirement.

------------------------------------------------------------------ID: 2370 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

"Maximum Local Average Revisit Time""Maximum Local Refresh"

Recommendation:

These terms seem to apply to an entire program rather than to an individual instrument.

Rationale:

Please clarify why they are assigned to a specific instrument. Isn't it sufficient to specify the swath width?

Response:

"Maximum local average revisit time" and "maximum local refresh" are not requirements levied on the sensor contractor, and therefore these attributes are not numbered like the other EDR attributes which are requirements for the sensor contractor. It is adequate to specify swath width for the sensor design. However, for algorithm development it is important to know how many new measurements can be accumulated between successive issuances of an EDR. The reason for this is that for some EDRs multiple looks with different viewing geometries could be exploited to improve the quality of the EDR. The number of looks between successive issuances of an EDR can be estimated base on the maximum local average revisit time and the maximum local refresh, and it is for this reason that these attributes are included in the EDR tables.

------------------------------------------------------------------ID: 2371 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

3.2.1.6 Standard Earth Scenes

Recommendation:

Number and types of scenes.

Rationale:

For chlorophyll, the number of scenes may not be adequate for modeling and for the WPTB.

Response:

Standard scenes are not being made to aid in modeling, either by the contractor or by the government. They will be used to assess performance of sensor designs and algorithms against EDR thresholds, by the contractor and the IPO with their respective set of scenes. If the number or type of scenes are believed to be insufficient to accomplish this assessment for chlorophyll, the contractor should make specific recommendations what scenes are necessary.

------------------------------------------------------------------ID: 2372 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

3.2.1.10.1

Recommendation:

Definition of "Scan Type".

Rationale:

This term is not defined and needs clarification. Does it refer to conical vs. crosstrack; if crosstrack, whiskbroom vs pushbroom, for example?

Response:

The presumed meaning of "scan type" is correct. A definition of this term has been added to the VIIRS SRD.

------------------------------------------------------------------ID: 2373 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

3.2.1.21.3 Out-of-Field Response

Recommendation:

What is its definition?

Rationale:

This term is not defined and needs clarification. It is a major issue for ocean color/chlorophyll near clouds.

Response:

A definition is provided in Section 3.2.1.21.3 in parentheses, namely, "integrated response outside the IFOV". An out-of-field response requirement might be of the following form:

"The integrated response outside the nominal pixel IFOV shall be less than one percent of the response within the nominal pixel IFOV."

Definitions of many of the sensor parameters which we anticipate will be addressed via derived requirements have not been provided because the government expects the sensor contractor to be familiar with these terms. Since virtually all of the VIIRS instrument requirements are TBD, the government expects the sensor contractor to provide precise definitions together with the derived requirements. The government does not see a need to impose uniformity of definitions for the sensor-level parameters that are not the subject of requirements within the RFP.

------------------------------------------------------------------ID: 2374 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 VIIRS SRD

3.2.1.28 Stray Light Rejection

Recommendation:

What is its definition?

Rationale:

This term is not defined and needs clarification. It is a major issue for ocean color/chlorophyll.

Response:

Stray light refers to any unwanted scattered or diffracted radiation in any spectral band which can potentially be detected by the instrument. Stray light sources include radiation reflected from spacecraft and instrument surfaces, as well as bright earth scene regions either within or outside the instrument field of view that can contaminate the response in pixels viewing nearby darker earth scene regions. The government expects the sensor contractors to understand the meaning of stray light rejection and to impose appropriate specific requirements in this area in the contractors' derived instrument specification.

------------------------------------------------------------------ID: 2375 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix A (Version 2.0a, 11/15/96) - V2 unpaginated

Particle size

Recommendation:

The previous reference to "particle size", based on 40.3.1.2, is "particle size parameter". This is inconsistent. Same comment for TRD, p. B-10

Rationale:

Add "parameter" to heading.

Response:

The glossary reference has been changed to "particle size parameter".

------------------------------------------------------------------ID: 2376 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix A (Version 2.0a, 11/15/96) - V2 unpaginated

Significant Wave Height

Recommendation:

The definition of "Significant Wave Height" appears twice, once right after "Satellite" and again (where it should be) after "Shortwave Radiation." The two definitions are different.

Rationale:

Eliminate the incorrect definition and put correct definition in proper sequence.

Response:

The "out of order" defintion has been deleted and the remaining definition slightly revised.

------------------------------------------------------------------ID: 2377 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix D (Version 2, 18 Feb 97) - V2 Paragraph 40.3.1.2, p D-17

Aerosol particle size parameter

Recommendation:

The delta in the equation in undefined.

Rationale:

Define all the terms of the equation.

Response:

A definition has been provided in the VIIRS SRD.

------------------------------------------------------------------ID: 2378 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix D (Version 2, 18 Feb 97) - V2 Paragraph 40.8.3, p. D-40

Auroral Imagery

Recommendation:

EDR talks about imaging the aurora in the IR, vis, far UV, and X-ray spectral regions, yet the measurement range given the the table only mentions 120-180nm which is the far UV region. Either add the other spectral regions to the table or eliminate discussion of them in the text.

Rationale:

Correct table or text.

Response:

The government recognizes that there are inconsistencies in the SES requirements and is seeking clarification through an internal study. In the meantime, the following sentence has been added to the text for this EDR: "The table below gives some information on requirements for the far-ultraviolet; requirements for other spectral ranges are TBR".

------------------------------------------------------------------ID: 2379 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix D (Version 2, 18 Feb 97) - V2 Paragraph 40.7.1, p. D-32

Currents

Recommendation:

Why is the term "near shore" mentioned when the table uses the term "coastal"?

Rationale:

Replace term.

Response:

The term "near shore" has been replaced by "coastal" in the VIIRS SRD.

------------------------------------------------------------------ID: 2380 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD Appendix D (Version 2, 18 Feb 97) - V2 Paragraph 4.7.3, p. D-34

Ice Surface Temperature

Recommendation:

It is stated the "objective is to measure the atmospheric temperature 2m above the surface of the ice". Is this a precise height measurement referenced to the mean flow surface? Or is this a nominal figure like ocean surface temperature?

Rationale:

Please clarify.

Response:

We believe it is a nominal figure but we will confirm this with the end users.

------------------------------------------------------------------ID: 2381 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD (Version 2, 18 Feb 97) - V2 Paragraph 3.2.1.1, p. 11

Performance requirements for each system mode

Recommendation:

Replace "speartely commend" with "separately command".

Rationale:

Typo.

Response:

Accept. Corrected.

------------------------------------------------------------------ID: 2382 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD (Version 2, 18 Feb 97) - V2 Paragraph 3.2.3.1.6, p. 19

External Interface to Search and Rescue System

Recommendation:

Suspected typo in 3rd line -- 406.025 should probably be 406.05

Rationale:

Typo.

Response:

Accept. Changed to 406.05.

------------------------------------------------------------------ID: 2383 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD (Version 2, 18 Feb 97) - V2 Paragraph 3.3.12.4.2

Pressure Loads

Recommendation:

What is the difference in the two entries for Pneumatic Vessels in Table II? Also same comment about composite vessels as in 024. Same comment on Table IV on page 47.

Rationale:

Please clarify.

Response:

In both tables there are actually three entries for values. The Design column provides values on which the contractors must base their design. The other Acceptance/Qulification columns give the values to which the components will actually be tested. First for acceptance and then for qualification. Note that the table says "no measureable yielding is permitted at acceptance and no rupture at qualification.

------------------------------------------------------------------ID: 2385 Date Recvd: 2/28/97 Status: Closed

Reference:

All SRDs - V2 SRDs, Para. 3.2.4.4

Threat and Survivability

Recommendation:

Survivability requirements should be imposed up front on the sensor designs. Appendix B is now non-existent. At least the normal space radiation environment should be specified as a design environment. The sensors shall be designed to withstand the energetic particle radiation due to Trapped Proton Environment, Trapped Electron Environment, Energetic Solar Proton Fluence, and Cosmic Ray Fluxes.

Rationale:

Unless the requirements are benign, imposing them after sensor design will incur cost increases which will be higher than if they were taken into account early in the design phase.

Response:

The government has determined that the requirements for survivalibility against non-natural threats which are applicable at the sensor level will not be sensor cost drivers. These requirements will be provided after award.

The normal radiation environment is specified in the following SRD references:

SRDX3.2.4.7.3.2-2

The environmental fluxes, as shown in Table 3.2.4.7.3.2 below, shall add solar, albedo and earth IR hot fluxes for the hot case analysis and cold fluxes for the cold case analysis

SRDX3.2.6.1-1

The sensor shall meet all performance requirements specified in this SRD while operating in the environments specified in (TBS) - : MIL-STD-1809 (USAF) Space Environments for USAF Space Vehicles; NASA SP-8031: NASA Space Vehicle Design Criteria / Structures; NASA Tech Memorandum 100471: Orbital Debris Environments for Spacecraft Designed to Operate in Low Earth Orbit; and the Handbook of Geophysics and Space Environments).

Radiation levels are also addressed in paragraph 3.2.4.7.3.2 Radiation.

------------------------------------------------------------------ID: 2386 Date Recvd: 2/28/97 Status: Closed

Reference:

All SRDs - V2 Para 3.2.4.9.4 High Rate Data Packetization

SRDX 3.2.4.9.4-1 - All data to be transferred to the spacecraft C&DH via the high rate data bus shall be packetized using the CCSDS Path Protocol Data Unit format defined in CCSDS 701.0-B-1.

Recommendation:

This requirement drives a functional design where the sensors perform all onboard data processing functions pertaining to mission data or the spacecraft processor must undo sensor functions prior to mission data processing.

If sensors only format the raw sensor data prior to passing the data across the high rate data bus, the spacecraft processor must unformat this data before performing the following functions:

1) All geo-location of sensor data for RDR production

2) Any data resampling for global and regional resolution.

3) Any data resampling and/or reduction for realtime links

4) All lossless data compression

5) All lossy data compression

6) Any lossless data compression with calibration coefficients

7) Any combination or simultaneous combinations of the above.

If, as stated in Para 3.2.1.9 Data Formatting and Compression (TBR), SRDV3.2.1.9-2 and SRDV 3.2.1.9-3, the VIIRS, and possibly the CRIS, shall perform data compression of raw sensor data, the worst case scenario for sizing the data processing within the VIIRS and/or CRIS sensors would include the following parallel functions:

1) Regional resolution lossless data compression and CCSDS Packetization for onboard storage.

2) Global resampling of raw sensors data, lossless data compression, and CCSDS Packetization for onboard storage.

3) Lossy compression of regional resolution data, possibly after data reduction for high rate data terminals, and CCSDS Packetization for realtime high rate data terminals.

4) Lossy compression of regional resolution data, possibly after data reduction for low rate data terminals, and CCSDS Packetization for realtime low rate data terminals.

5) Lossless compression of regional resolution data with sensor calibration coefficients, possibly after data reduction for high rate data terminals, and CCSDS Packetization for realtime high rate data terminals.

Rationale:

The minimum processing capacity (as well as potential future growth capacity) required to simultaneously accomplish the tasks identified in the above table will have a significant impact on the sensor designs. The throughput and memory capacity requirements for data processors integrated into the VIIRS and CRIS sensors will add significant complexity, cost and risk factors to the development.

A benchmark test was conducted to determine the processing capacity required to compress 2:1 a VIIRS-type data produced at 3.4 mbps. Five RH32-type equivalent 25 mhz processors were needed just for this task. The worst case scenario shown in the above table, would require the equivalent of 25 RH32 processors in the VIIRS sensor. An additional set of 6 to 10 RH32 type processors would be required for the CRIS sensor. The addition of the processors within each sensor may increase the weight, and power envelops for of the sensor design and almost certainly, due to the processor heat loads, will impact the thermal characteristics of the sensor. .

Performing the above tasks within the sensors delays the incorporation of any spacecraft data necessary to generate sensor raw data records (RDRs) such as the satellite ephemeris data sufficient to geo-locate each data sample. .

Packetizing prior to on-board storage will increase the required storage capabilities by approximately 15% or more. These various sensor streams would have to be merged by the spacecraft and formed into some new packet format, thereby increasing the complexity in the satellite as well as on the ground. .

All mission planning command inputs for a) specifying the portion of the orbit to collect high resolution data, b) change in content/format of the regional users downlink data stream, and c) other adaptable processes will have to be routed to and be processed by the sensors. This could all be handled much more efficiently by having all mission data processing done in one central location, i.e., in the spacecraft.

Recommendation: Conduct a trade study to determine the advantages and disadvantages of this processing approach.

Response:

A provisional decision has been made by the government to perform all of the functions listed in the comment (except geolocation and resampling) within the sensor, not within the spacecraft computer. The rationale for this decision is to simplify the S/C by limiting its processing to routing and merging the sensor data, including the insertion of headers as needed. This approach limits the impact on the S/C of accomodating different payload complements. Note however that this is TBR and will be investigated further during Phase 1 through an Interface Working Group with the system level contractors. The sensor contractors will be able to forward issues to the IWG through their IPO contract monitor.

Geolocation of data will be performed on the ground by the IDPS. The S/C related data needed for geolocation is inserted into the RDR data stream at regular intervals (every five minutes for the VIIRS). The S/C can send these data to the sensor and the sensor can insert the data into its output data stream, or the S/C can insert these data directly into the sensor output data stream. Either way, there would be no delay in the generation of RDRs associated with the insertion of geolocation data.

Resampling of data will be performed on the ground by the IDPS, as needed. Aggregation of VIIRS pixel data will be performed by the VIIRS. We do not view aggregation as a function which is appropriate for the S/C, except perhaps in a backup mode for redundancy.

------------------------------------------------------------------ID: 2387 Date Recvd: 2/28/97 Status: Closed

Reference:

All SRDs - V2 SRDs, Para. 3.2.4.2.1.3

Alignment

Recommendation:

Paragraph 3.2.1.12.2.1 states that "The CMIS contractor shall be responsible for meeting the EDR Earth location requirements, based on the allocations from the spacecraft level as specified in Section 3.2.4.2.1.3." Need to add an allocation for jitter (approx. 5 a-s, 1 sigma) and ephemeris (approx. 50 a-s, 1 sigma) in the referenced section.

Rationale:

The referenced paragraph needs to include other parameters in addition to 'alignment'; namely, jitter and ephemeris to determine 'geo-location'.

Response:

We believe we have this covered in Section 3.2.4.1.3.5 of the 3-17-97 release. Further issues in this area will be worked in an Interface control working group.

------------------------------------------------------------------ID: 2388 Date Recvd: 2/28/97 Status: Closed

Reference:

All SRDs - V2 SRDs, Para. 3.2.4.2.1.3.4

Alignment Knowledge

Recommendation:

Recommend adding "1 sigma" to the alignment allocations in the two sub-paragraphs after "25 arcsec per axis" and "10 arcsec per axis".

Rationale:

Although "Mapping Uncertainty" in the glossary states 1 sigma it may not be obvious that this applies to the above paragraph.

Response:

Mapping uncertainty does apply to the alignment allocations. All values are one sigma unless otherwise specified.

------------------------------------------------------------------ID: 2389 Date Recvd: 2/28/97 Status: Closed

Reference:

All SRDs - V2 SRDs, Para. 3.2.4.3.2

Sensor External Power

Recommendation:

Recommend changing 28ñ1V to 28ñ6V.

Rationale:

Even though there is a TBR noted, It might be better for the sensor contractors to plan for the worst case. It would have less sensor impact to change to a tighter tolerance than a looser tolerance at a later date. This specification change would reduce the regulation requirements for the spacecraft.

Response:

There are different philosophies on which side of the interface do we impose the tighter tolerance. Changing to a wider tolerance may be easier for the sensor contractors but will certainly impact the spacecraft. However, we have decided to change the power to 28 +/- 6 v. (TBR).

------------------------------------------------------------------ID: 2390 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 SRDC3.2.1.1.1.1.1-4 Snow Cover/Depth, C40.6.3-9 Cloudy and/or nighttime

Recommendation:

Change threshold from "20% (snow/no snow)" to "20% (snow/no snow) except for dry snow."

Rationale:

Dry snow is essentially undetectable at most microwave frequencies. This restricts the measurement under cloudy/nighttime conditions to wet or refrozen snow.

Response:

Recommendation rejected. The IPO disagrees with the comment that dry snow is essentially undetectable at microwave frequencies. There is at least one reference in the literature (Microwave Remote Sensing by Ulaby, Moore and Fung, Volume III, pp. 1627-9) which suggests that it is relatively straight-forward to separate snow-free areas from areas covered with dry snow. It may be worth noting that since the dry snow signature is dependent on snow depth, it may be difficult to successfully perform these measurements for snow cover of less than 1 or 2 cm, so that in some cases, yes, it may be hard to detect thin, dry snow cover. Please note that the Measurement Uncertainty in the SRD is suffixed with a TBR, so the IPO will continue to examine the measurement requirements which we have specified. Also note that the CMIS SRD, Section 3.2.1.1.1, requests "In the event the requirement for an EDR cannot be fully satisfied, the contractor shall identify the requirements which are not fully satisfied, and specify the conditions when it will not be satisfied."

------------------------------------------------------------------ID: 2391 Date Recvd: 2/28/97 Status: Closed

Reference:

CMIS SRD - V2 Section 3.2.1.1.1.1, EDR 40.2.1, EDR 40.2.2, EDR 40.3.3, EDR 40.3.4, EDR 40.3.5, EDR 40.3.6, EDR 40.4.4, EDR 40.4.5

Recommendation:

These EDRs all have global horizontal coverage requirements, yet the associated CMIS swath width for these EDRs is specified as 1700 km (TBR).

Change CMIS swath width for these EDRs to 1946 km (TBR) or...

Change the definition of global coverage in Appendix A of the TRD to allow "polar holes" that would allow the smaller swath widths. In this case, the definition of global coverage might be written as:

"Global coverage denotes the observation of all points on the Earth or its atmosphere, with the exception of a 250 km diameter gap centered over each pole, at least once per given time period (consistent with observational requirements), and implies use of recorded data."

Rationale:

As described in an engineering memorandum, global coverage is only provided by a CMIS swath width of 1946 km. The specified 1700 km swath will result in a 246 km gap in the polar regions. We note that the 1700 km specification is cited as (TBR) but (1) to allow the most conservative sizing of the CMIS, (2) to provide initial correlation and compliance with the requirements of the IORD, TRD and the CMIS SRD and (3) to facilitate internal correlation, compliance and requirements flowdown within the CMIS SRD, the 1700 km specification should be replaced with the specification of 1946 km (TBR).

Alternatively, a modification to the definition of global coverage as it appears in Appendix A of the TRD which would allow limited polar coverage gaps would also be satisfactory.

Response:

Defintion revised as follows: "Global coverage denotes the observation of all points on the Earth or its atmosphere (with the exception of gaps centered over the poles consistent with the allocated swath width), at least once per given time period, and implies use of recorded data."

------------------------------------------------------------------ID: 2392 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD - V2 Pg 27, Sec 4, Para 3.2.4.6

TRD3.2.4.6-4 The design service life of the satellite shall be at least 154 years. This includes the time allowed for test, storage, prelaunch checkout, launch and injection, on-orbit, recovery, and contingency.

Recommendation:

Appears to be a typo in the design service life. To be consistent with the glossary definition, 154 years should be changed to 15 years.

Rationale:

Response:

Accept.

------------------------------------------------------------------ID: 2393 Date Recvd: 2/28/97 Status: Closed

Reference:

TRD - V2 Pg 52, Sec 4, Para 3.7.1.1

Recommendation:

TRD3.7.1.1-1 NPOESS satellites shall be flown at a nodal crossing time of approximately 0530 LST (ascending), approximately 1330 LST (ascending), and 2130 (ascending) to optimize satisfaction of DoD and DOC requirements. The 0930 orbit may be satisfied by METOP flying NPOESS furnished sensors. If the 0930 orbit is satisfied by the METOP satellite, then only two US NPOESS satellites will be needed; they will be flown in the 0530 and 1330 orbits.Reference to the 0930 orbit in the second sentence should be changed to 2130.

Rationale:

To be consistent with the orbit descriptions in the first sentence.

Response:

Accept. Changes made to TRD and applicable section of SRD.

------------------------------------------------------------------ID: 2394 Date Recvd: 2/28/97 Status: Closed

Reference:

VIIRS SRD - V2 (1) SRDV3.2.1.1.2.1-1 and (2) SRDV3.2.1.1.2.1-2

Recommendation:

Item 1 SRDV3.2.1.1.2.1-1

Definitions of "clear" and "cloudy" appear in Section 40.1.8.1 40.1.7 of Appendix D.

Rationale:

for Item 1: Correct the Section number

Item 2 SRDV3.2.1.1.2.1-2

Delete: The contractor shall recommend definitions of "clear" and "cloudy". Different definitions may be proposed for different EDRs.

Replace with: The contractor shall demonstrate the measurement uncertainty of each EDR for the following cloud covers:

1. Clear: no clouds in the Instantaneous Field of View (IFOV)

2. Scattered Clouds: 20% of a scene covered by clouds

3. Broken Clouds: 60% of a scene covered by clouds

3. Overcast: 100% of scene is cloudy.

For the purpose of simulating the sensor and algorithm performance, the clouds will have the following characteristics (TBR): (a) the clouds are composed of elements with a characteristic diameter of 6 km and are randomly distributed over a scene of 360 km X 360 km, (b) the cloud bases are 2 km above the surface, (c) the clouds are 1 km thick, and (d) their Cloud Liquid Water Content is 1 mm.

Rationale for Item 2: By leaving the definition of "clear" and "cloudy" to the sensor contractors, it is almost certain that each contractor will use a different definition. Thus, it will be difficult to compare the relative performance of two competitors. Also a contractor may define cloudy as being 50 % with half of the scene being completely overcast and the other half being completely clear. This could lead to quite a different outcome than assuming the scene is composed of randomly distributed cloud elements of a given size with the total cloud cover of the scene being 50 %. For the purpose of algorithm performance, the main problem is identifying the IFOVs that are partly cloud filled, and thus it is better to specify cloud elements that are small enough to result in many IFOVs that will be partially contaminated with cloud.

Response:

As stated in Section 3.2.1.6, the government will evaluate contractor design and algorithm performance based on standard scenes. These standard scenes are for government-internal evaluation purposes and are different from the standard scenes that will be furnished to the contractors for design and algorithm development. Consequently, the level of EDR performance under all levels of cloudiness represented in the government-internal standard scenes can be assessed on a common basis for the competing VIIRS contractors, irrespective of any definitions of "clear" and "cloudy" provided by the contractors. The sensor contractor's definitions of "clear" and "cloudy" conditions reflect his own assessment of the robustness of his design and algorithms. If one contractor purports to meet thresholds under a greater degree of cloud contamination than another, and if more robust performance is borne out in government simulations using the contractor's design and algorithms and the government-internal standard scenes, then this contractor would be at an advantage in this respect.

------------------------------------------------------------------ID: 2395 Date Recvd: 2/28/97 Status: Closed

Reference:

VIIRS, CrIS, OMPS and CMIS SRDs - V2 "Algorithms" Section of the VIIRS, CrIS, OMPS, and CMIS SRD

Recommendation:

The following is the recommendation for changes to the "Algorithms" Sections of the CMIS, VIIRS, CrIS, and OMPS SRDs. The "Algorithms" Section for the CMIS SRD is taken as the model to be used for the VIIRS, CrIS and OMPS. The existing "algorithms" sections of the VIIRS, CrIS, and OMPS SRDs would be deleted in their entirety and replaced by the sample section modeled after the CMIS SRD. In addition, recommended changes to the CMIS "Algorithms" Section of the SRD are included in bold and italics font. The word "sensor" would be replaced by the applicable sensor for each SRD (i.e. CMIS, VIIRS, CrIS, OMPS). References to specific paragraphs in the CMIS model below will have to be changed to match the corresponding paragraphs for VIIRS, CrIS and OMPS Sensors.

Replace the following paragraphs:

FOR VIIRS

3.2.1.5 Algorithms [TBR]

3.2.1.5.1 through 3.2.1.5.4

FOR CrIS

3.2.1.1.4 Algorithms

SRDK3.2.1.1.4-1 through SRDK3.2.1.1.4.1.-3

FOR OMPS

3.2.1.1.5 Algorithms [TBR]

3.2.1.1.5.1 through 3.2.1.1.5.4

with the following:

SRDC3.2.1.1.5-1

The Sensor vendor shall provide to the IDPS the algorithms and sensor data necessary to process RDR data into SDR data. EDR science retrieval algorithms shall be provided by the Sensor contractor.

SRDC3.2.1.1.5-2

The Sensor science retrieval algorithms shall provide EDRs which satisfy the NPOESS requirements as specified in Section 3.2.1.1.1.1. Science algorithms may also be recommended by the government's Operational Algorithm Teams (OATs). These teams have contributed to the definition of the instrument requirements of Section 3. The OATs may also provide advisory information on Sensor functional and calibration requirements.

SRDC3.2.1.1.4.2-3

The contractor shall identify the use of any ancillary data required for algorithm processing.

3.2.1.1.5-1 Convertability to Operational Algorithms

The government considers the SDR and EDR algorithms adopted, adapted, or developed by the Sensor contractor to be scientific, rather than operational, algorithms. The Sensor contractor is not responsible for identifying or developing operational SDR and EDR algorithms for the Sensor. (Any operational algorithms necessary for the generation of RDRs will ultimately be the responsibility of the Sensor contractor, and the operational software implementing these algorithms will be part of the required flight software. This statement applies to the post-downselect phase of the Sensor program.)

SRDC3.2.1.1.5-2

The scientific SDR and EDR algorithms delivered by the Sensor contractor shall be convertible into operational software that is compatible with a 20 minute maximum processing time at either the DoD Centrals or DoD field terminals for the conversion of all pertinent RDRs into all required EDRs for the site or terminal, including those based wholly or in part on data from other sensor suites. The intent of this requirement is to preclude algorithms that are so computationally intensive that any foreseeable implementation would stress or exceed the time available for delivery of EDRs in an operational environment.

SRDC3.2.1.1.5-2

The means by which the contractor shall validate the requirement that scientific algorithms be convertible to operational software subject to the constraint specified in SRDC3.2.1.1-1 is TBR.

SRDC3.2.1.1.5-3

The availability of any inputs required from data bases or other ancillary sources to generate data products shall also be adequate to allow EDRs to be generated at the DoD Centrals and DoD field terminals within the time constraint specified in SRDC3.2.1.1.5-1.

3.2.1.1.5.2 Performance Requirements

SRDC3.2.1.1.5.2-1

The performance of the scientific EDR algorithms delivered by the Sensor contractor shall meet EDR thresholds.

SRDC3.2.1.1.5.2-2

The performance of the Sensor science algorithms shall be no worse than the performance of algorithms utilized for current (TBR) operational data products for these EDRs, if such operational products exists.

Rationale:

It is our interpretation that the IPO intends the SRD contractors to provide "scientific" retrieval algorithms for the TDRs, SDRs, and EDRs, and these will be provided to the IDPS contractor for conversion to operational data records. Moreover, the sensor vendor shall identify and/or provide to the IDPS the algorithms, sensor data, and ancillary spacecraft data to process the TDR, SDR, and EDR as applicable.

The CMIS SRD states these requirements in a more concise manner, as illustrated in our "Comment" section above, compared to the SRDs for the VIIRS, CrIS, and OMPS. The SDR/EDR descriptions specified in the latter three SRDs are confusing, and at times vague and/or ambiguous. For example, an interpretation could be made (using the VIIRS, CrIS or OMPS SRDs) that the IDPS contractor is solely responsible for defining the contents of an SDR whereas our interpretation is that the sensor contractor defines what needs to be in the SDR and provides the algorithms necessary to manipulate the RDR (and ancillary spacecraft) data into the SDR. The RDR requirement, as stated in paragraph SRDV3.2.1.3.1-1 for the VIIRS, is for the sensor contractor to generate the operational RDRs as would be the case for the other sensors.

Response:

The recommended requirement "The Sensor vendor shall provide to the IDPS the algorithms and sensor data necessary to process RDR data into SDR data." is incorrect. The sensor vendor does not provide sensor data at all. The sensor vendor will ultimately provide sensors and flight software to the government, and the government will provide these items as GFE to the TSPR contractor. The flight software will implement the operational code for generation of RDRs. The sensor contractor will provide the scientific algorithms for generation of SDRs, TDRs, and EDRs to the government, and the government may furnish these algorithms to the TSPR contractor, who is responsible for the IDPS, as a basis for generating operational algorithms. It is not anticipated that the sensor contractor will provide algorithms directly "to the IDPS", as the commentator states, or to the IDPS contractor.

The interpretation stated in the Rationale section to the effect that the sensor contractor, rather than the IDPS contractor, defines the content of the SDR is also incorrect. The TSPR contractor, as the IDPS contractor, is responsible for all operational data products except the sensor RDRs. As such, the TSPR contractor is responsible for determining the content and format of operational SDRs, TDRs, and EDRs, not the sensor contractor.

The VIIRS SRD captures the government's intent with respect to the parties responsible for scientific and operational algorithms, and for data product content and format, and the parties to whom these items will be provided.

------------------------------------------------------------------ID: 2396 Date Recvd: 2/28/97 Status: Closed

Reference:

- V2 Paragraph 3.2.4.0.2, Dimensions

Recommendation:

We recommend that the dimensions be TBD.

Rationale:

Dimensional constraints, especially for antenna aperture, unduly restrict the scope of design flexibility, particularly for selection of frequency bands and channelization. At this phase of the process, the fairing envelope information in 3.2.5.1 of the IRD provides sufficient guidance.

Response:

Physical and interface characteristics values, to include volume, refer to the complete sensor and/or associated sensor suite (to include all associated subsystems, components, electronics, etc.). Note: Weight, power, volume, and data rates described in section 3.2.4 are nominal values (with contingency) which were developed during initial studies at the Integrated Program Office. All values are defined as: (TBR), indicating that specific allocations are negotiable. It is presently planned that definitive allocations will be defined by the IPO, in consultation with sensor contractors, by the time of SRR. In the interim, contractors should keep in mind that relaxation from nominal allocations will only be possible if changes are consistent with the requirement to accommodate the full NPOESS payload suite of instruments on a spacecraft which can be placed into a nominal 833 Km orbit by an EELV class launch vehicle.

------------------------------------------------------------------ID: 2397 Date Recvd: 2/28/97 Status: Closed

Reference:

- V2

Recommendation:

We recommend that the data rates be TBD. If numbers are to be given, they should at least be TBR.

Rationale:

Data rate allocations, at this phase of the program, unduly restrict the scope of design flexibility, particularly regarding channelization, resolution, and sampling design trades. This is particularly the case for the CMIS, since it's data rate is likely to be a small percentage of the total NPOESS sensor suite.

Response:

------------------------------------------------------------------ID: 2398 Date Recvd: 2/28/97 Status: Closed

Reference:

- V2 Paragraph 3.2.1.1.1.1 EDR Requirements

Recommendation:

We recommend that Land Surface Temperature and Vegetation Index/Surface Type EDRs be moved from "Primary EDRs" to "Secondary EDRs".

Rationale:

This would make it consistent with paragraphs 3.1.1 and 3.1.7.

Response:

Reject. It is intended that CMIS as well as VIIRS are both to consider themselves primary for these two EDRs. Sections 3.1.1 and 3.1.7 are not inconsistent with this direction. Note that the Horizontal Cell Size is different for the two sensors. Note that the word "Index" was deleted and it is vegetation type and Surface type that are being asked for.

------------------------------------------------------------------ID: 2399 Date Recvd: 2/28/97 Status: Closed

Reference:

Cover Letter to Draft #2 RFP Release - V2

Fixed price contracting for current contract phase.

Recommendation:

Request that the contract type for the current phase remain as cost-type.

Rationale:

Fixed-price contracting is potentially feasible in this phase but, we believe, will not be in the best interests of either the Government or the contractors for the following reasons. First, there will probably be more programmatic changes over the next three years, and fixed-price contracting in this type of environment would provide the IPO with significantly less flexibility to deal with such changes. Second, to establish an appropriate cash-flow, the Government would either have to (1) establish interim deliverable items to liquidate progress payments against, or (2) authorize milestone payments, because under normal fixed-price payment terms, contractors would only be paid 80% of their costs until the end of the study (three years after ATP).

Response:

The contract type remains CPFF.

------------------------------------------------------------------ID: 2400 Date Recvd: 2/28/97 Status: Closed

Reference:

RFP Annex A Sensor Work Breakdown Structure - V2 Sensor Work Breakdown Structure DICTIONARY

WBS Item Definitions

Recommendation:

We assume that the IPO will provide data to replace TBS entries for all paragraphs 1.0 through 1.3.10 in the final RFP.

Rationale:

Clarification of requirements

Response:

Yes. The TBS in the WBS dictionary will be provided in the final RFP.

------------------------------------------------------------------ID: 2401 Date Recvd: 2/28/97 Status: Closed

Reference:

Second Draft Request For Proposal Cover Letter- V2 Potential revision of contract type to Firm Fixed Price (FFP) for the first phase

Recommendation:

We recommend maintaining a Cost Plus Fixed Fee (CPFF) contract type for the first phase.

Rationale:

We Believe it is not in the best interest of the government, nor the contractor, to enter into a Fixed Price contract for this effort. The lack of definitive specifications, the costs associated with this effort would be difficult to impossible to estimate with any degree of confidence or accuracy typically associated with fixed price arrangements. Throughout the RFP there is mention of evaluating alternative designs to provide the optimal "Best Value" product to the government during the hardware phase which will not begin for several years. This desire, combined with the requirements defined, require the use of designs which are currently developing and evolving. To constrain a contractor to a fixed price arrangement this early would force decisions to be made in the short term which would affect the ultimate performance and value to the production efforts. A cost reinbursement type contract is the only contract type which will provide the tools necessary to develop and design the "BEST VALUE" sensor.

Response:

The contract type remains CPFF.

------------------------------------------------------------------ID: 2402 Date Recvd: 2/28/97 Status: Closed

Reference:

Section B - G - V2 CLIN 0019

CLIN amount

Recommendation:

The descriptive data of this CLIN states "The estimated cost and fixed fee of this item is included in CLIN's 0016 and 0018". However, this CLIN has fill-ins that would establish separate pricing of data and reports. Recommend that these fill-ins be replaced with the term "NSP", as was the case in the first draft RFP release (CLIN 0016 in that document).

Rationale:

To establish consistent RFP requirements.

Response:

The Government requires that data costs be included in the proposal IAW AFMC FAR Supplement 5315.873, Estimated data prices. For this acquisition, offerors are required to complete the fill-ins for the Data & Reports CLINs. However, this cost information will be replaced with the term "NSP" in the awarded contracts.

------------------------------------------------------------------ID: 2403 Date Recvd: 2/28/97 Status: Closed

Reference:

Section H - V2 Paragraph 5352.243-9000, AFMC FAR Supplement

Recommendation:

We recommend that the change value be reduced back to $25, 000 as stated in the original DRFP.

Rationale:

The value of $500,000 per change is excessive. As a contractor we are willing to accept this clause with a value which is more appropriate and a contract type of CPFF.

Response:

The value of $500,000 represents an editorial error in the DRFP. The intended value was $50,000. The clause will be revised for the final RFP.

------------------------------------------------------------------ID: 2404 Date Recvd: 2/28/97 Status: Closed

Reference:

Section H - V2 H5, Technical Interchange meeting with Advanced Technology Support Program contractors

Recommendation:

Is Lockheed Martin/Sanders a mistake?

Rationale:

Response:

No. Lockheed Sanders is the official ATSP contractor. In this case, they serve as the contract administrators while Lockheed Martin Missile & Space executes the contract.

------------------------------------------------------------------ID: 2405 Date Recvd: 2/28/97 Status: Closed

Reference:

Section H - V2 Clause 5352.243-9000, "Advance Change Adjustment Agreement"

"No-cost" change threshold

Recommendation:

The threshold was changed from $25K in the first draft RFP to $500K. Request that this clause be revised to return to the original $25K threshold amount.

Rationale:

The value of $500,000 is very high given the dollar value of the instant procurement. Offerors, in a competitive situation, will not include any contingency for unforeseen changes in this dollar range, and therefore, such a provision will probably put upward pressure on actual costs if only a few of such changes close to this threshold were ordered by the Government. Recommend that the threshold be increased when the EMD phase is awarded.

Response:

The value of $500,000 represents an editorial error in the DRFP. The intended value was $50,000. The value will be revised for the final RFP.

------------------------------------------------------------------ID: 2406 Date Recvd: 2/28/97 Status: Closed

Reference:

Section L - V2 Paragraph 5352.232-9002, AFMC FAR Supplement

Recommendation:

Increase CMIS funding in 1998 to $8 Million and reduce 1999 funding to $17 Million.

Rationale:

During the SRR and SFR portions of the contract it will be necessary to work with key suppliers and evaluate alternative approaches. To adequately perform this task higher funding levels are required early on. The 1997 funding level of $2 Million appears adequate given that the contract award is late July 1997.

Response:

The funding profiles have been revised to reflect annual targets in developing the proposals.

------------------------------------------------------------------ID: 2407 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 3.2.4.0.2

Dimensions

Recommendation:

Restate size constraints as follows:

The CMIS instrument shall fit within the following stowed envelope:

TBS

The deployed swept volume occupied by the CMIS instrument shall be within the following envelope:

TBS

Rationale:

The contractor needs the flexibility to optimize the instrument design within the envelope restrictions.

Response:

------------------------------------------------------------------ID: 2408 Date Recvd: 2/28/97 Status: Closed

Reference:

DRFP Version 2 - V2 page196/197, Section L, 5352.232-9002 Program Budget Profile

Distribution of Sensor Budget among Fiscal Years

Recommendation:

"The Offerors should consider these estimates as annual targets or caps in developing their proposal." While intending to be fully compliant with this DRFP instruction, the net result may be less economical for the Program. If the offeror provides sufficient justification, is the distribution among fiscal years subject to realignment?

Rationale:

Response:

The Offeror should view the funding estimates to be annual targets. The reference to "caps" has been deleted. While there is no restriction in realigning the funding distribution among fiscal years, the government is not encouraging that this be done and cannot guarantee that the realigned budget will be available.

------------------------------------------------------------------ID: 2409 Date Recvd: 2/28/97 Status: Closed

Reference:

DRFP Version 2 - V2 page 220, Section L, 3.5.2.8 Attachment 8- Award Fee Plan

Offeror Fill-ins

Recommendation:

"Offerors shall fill in the required sections of the plan. No other changes to the Award Fee Plan will be allowed." Other that filling in the Offeror's name on page 3 of 23, it is unclear which open elements of the Plan are to be filled in at this time, and which are not to be changed at this time. Would appreciate amplification.

Rationale:

Response:

The Offeror's name on page 3 is the only place in the Award Fee Plan that shall be fill in at this time. Other changes to the plan will occur when the contract is definitized.

------------------------------------------------------------------ID: 2410 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 2.3.5.2 Proposal Information

Page Limit

Recommendation:

Increase Section 1 - Technical Approach page limit to the original 100 pages

Rationale:

The short delivery date, the extensive and supplemented evaluation criteria, and clarification to scope beyond the PDR down select make the task of reducing the technical volume to 75 pages a difficult task. It is harder to write a shorter proposal. It is hard to redirect a team, once the initial page allocation is made. Efforts to begin proposal activities before the release of the RFP are always difficult because changes to the interim drafts mean more cost. Some changes are absolutely necessary. Page count seems like a preference. We recommend a 100 page limit.

Response:

The previous limit of 100 pages was reduced to 75 pages because the oral presentations are now considered an integral part of the overall proposal. Technical and management information that are covered in the presentations should not be repeated in the written proposal thus allowing the reduction in the written proposal.

------------------------------------------------------------------ID: 2411 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 p. 218, Section 3.4.2 "NOTE"

Contracts in Development

Recommendation:

Please clarify. Do you mean "in development" or "currently in production"

Rationale:

It is unclear whether the phase "in development" refers to the development phase of a program or is just a general way of referring to ongoing work.

Response:

The wording will be changed to "in development/production"

------------------------------------------------------------------ID: 2412 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 p. 199, Section 1.2 Oral Presentations

Timing

Recommendation:

Please specify the date for the presentation of the oral presentations, in addition to the date when the requests to schedule a presentation time should be made.

Rationale:

Response:

Contact the PCO between 14-18 Apr 97 to schedule a presentation time. The presentations are scheduled at the ANSER Corp, Arlington, VA during the week 28 Apr - 2 May 97. Offerors for each sensor suite will be scheduled on a specific day.

------------------------------------------------------------------ID: 2413 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 P. 217, Section 3.4.2a

Government contracts

Recommendation:

Is the IPO interested in the ultimate Government contact, or the organization with whom we had our contract (if this was a university or private corporation)?

Rationale:

In Section 1, Contract Descriptions, the list of 12 items to be supplied for each contract discussed in Volume IV applies exclusively to contracts with the Government. We have held contracts with universities who hold the Government contract. We have been the prime instrument contractor to a firm that is, in turn, under contract to the Government. What information should be supplied in these cases, since information on the Government contract may not be readily available and they do not represent our immediate customer.

Response:

The offeror is only obligated to provide the contractual information for their contract entity, whether it be with a university, commercial, or government. If the information that is available is similar to the information requested for Section 1, then provide as much as possible. In most cases, a contract number or point of contact, with an address or phone number is sufficient for the PRAG to obtain the necessary information.

------------------------------------------------------------------ID: 2414 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 Paragraph 2.3.3, Proposal Test Period

Electronic Testing?

Recommendation:

In order to perform electronic testing on the Government's hardware configuration, are we required to send a representative to the site? Where will the testing take place?

Rationale:

Response:

The instructions will be revised to indicate that the offerors are invited to send in copies of sample files on disk or CD ROM for the government team to test on their electronic evaluation system. The offerors will not be required to send any representatives to the testing site at ANSER Corp. The testing period will be from 1 - 4 Apr 97. The government will provide feedback to the offerors on the readability of the files and the ability/failure of the hypertext links to transfer to the proper location.

------------------------------------------------------------------ID: 2415 Date Recvd: 2/28/97 Status: Closed

Reference:

L - V2 Paragraph 1.2, Oral Presentations

electronic copy of the presentation material

Recommendation:

Is that copy required on the date of the oral presentation AND on the CDs submitted with the rest of the proposal on 4/21/97?

Should the copy provided on the date of the oral presentation be prepared on a high density diskette or on a CD?

Rationale:

Response:

The copy of the electronic presentation will be submitted with the rest of the proposal as part of Vol I with the file name ORAL.PDF. The copy provided on the date of the presentation is not required. The offeror is free to have copies of the presentation available during the brieifng if he so desires.

------------------------------------------------------------------ID: 2416 Date Recvd: 2/28/97 Status: Closed

Reference:

Model Contract - V2 page 159, Section I, FAR 52.245-19 Government Property Furnished "As Is" (APR 1984)

Inclusion of this Clause in the Listing at (1), I. i.e. those Clauses that apply to all CLINs.

Recommendation:

The authorizing language at 45-308-1, (a) seems to limit the use of this Clause to fixed-price, T&M, Labor Hour and certain Facilities contracts. It is believed that the Clause should be included in the third listing, i.e., Clauses applying to all fixed-price development CLINs (if exercised). Please clarify.

Rationale:

Financial risk of program impact due to other than suitable GFP is believed to be inappropriate within the cost-type environment, absent allowable "contingency" costs.

Response:

The FAR clause 52.245-19 will be moved from the subset clauses applying to all CLINs to the subset of clauses applying to fixed-price (option) CLINs, as recommended, consistent with the prescription at FAR 45.308-1(a).

------------------------------------------------------------------ID: 2417 Date Recvd: 2/28/97 Status: Closed

Reference:

NPOESS RFP comments & Section M - V2 ID 1835 & p. 223 Section 1.0 General Basis for Contract Award

Past performance

Recommendation:

Please clarify? Is past performance equal to 50% of the evaluation?

Rationale:

The response to Question ID 1835, says, "Past Performance is equal to all these areas (technical, management and cost). Page 223 says, "equally with other areas."

Response:

No. Past performance is a major aspect in the source selection decision. The assessment of past performance (performance risk) is of equal importance to either the factor assessment (proposal rating) or the proposal risk within each of the areas (technical, management, and cost). Past performance is not considered another area but will be assessed at the factor level and rolled up to the area level, ie, a performance risk rating for the technical, management, and cost areas.

------------------------------------------------------------------ID: 2418 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 page 29, Section 3.2.1.25.4-1

NEDN discrepancies

Recommendation:

Table 3.2.1.25.4-1 on page 29 gives the maximum allowed NEDN values for each band and as a function of two test target temperatures. Problems with the table are:

a. Units at the top of the table - should be mW/m2-sr-cm-1, not mW/cm2-sr-cm-1.

b. Table entry, Column 3 T=233K should be 0.03, not .003.

Rationale:

NEDN values in the table are not in agreement with those shown in Figure 3.2.1.25.3-3 on page 28. In particular, the NEDN value for band 2 (1210 - 1540) at T=233 K is probably a typo, and the values for band 1 at 233 K are unachievably low.

Response:

Concur. Typographical errors which resulted in incorrect units and numerical values cited by comment generator in this section have been reviewed, corrected, and revised.

------------------------------------------------------------------ID: 2419 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 page 36, Section 3.2.4

Physical and Interface Characteristics

Recommendation:

Does the volume specification include electronics or is an additional volume available for these located elsewhere?

Rationale:

Page 36 gives the volume specification as 57 x 36 x 37 cm and a mass of 68 kg. Converting to lbs/cu-inch gives a density of 0.032 lbs/cu-inch. Historical values for other densely packed instruments are lower by a factor of approximately 1.5. It is therefore possible that the SRD intends for the mass requirement to include the optics module and a separate electronics module, but specified the volume for only the optics module.

Response:

------------------------------------------------------------------ID: 2420 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 P. 36, Section 3.2.4 Physical and Interface Characteristics

Dimensions

Recommendation:

The 57 X 36 X 36 cm dimensions are too restrictive. Please leave them open as part of the design activity.

Rationale:

Our review of the ITS study conducted by the University of Wisconsin and SBRS and the CrIS Draft 2 RFP/SRD shows that the physical dimension and other parameters are almost identical.

Much has happened since the original 1991 ITS study. We have conducted extensive study and development of the flat plate interferometer approach, completed two Thermal Emission Spectrometers (TES) for the Mars missions (that use flat plate and corner cubes for interferometry and phase measurement), and recalculated critical parameters for the ITS based on advanced conceptual designs, and the inclusion of a 95 degree gamma angle in the CrIS SRD.

All these evolutions contribute to a baseline CrIS approach that is more mature than ITS and whose dimensions exceed those of the Draft-2 SRD.

At the current dimensions and our recalculated heat load including 95 degree gamma:

(1) A passive radiative cooler, usually a low risk component, will be a high risk item, and

(2) The density of the instrument, including an active cryocooler would, at the 68 Kg mass limit and the stated dimensions exceed our most densely packed planetary instrument by a factor of 1.5.

As a builder of tens of thousands of tactical cryocoolers, as a builder of long life Split Stirling active cryocoolers, as a buyer of competitive coolers (TRW pulse tube) for special military applications, and as a builder of the highest performance, long-life passive radiative coolers we understand the difficult decision between the passive approach that has served us exceptionally well for long-life space sensors and the isn't-it-ready for operational service appeal of the active approach.

Based on this broad experience with active and passive coolers we can objectively address trades. We look forward to engaging the IPO in discussing these design issues during phase 1.

However, we feel that the Draft-2 SRD dimensions causes a premature decision to be made favoring the active cryocooler approach. Because so much of the SRD contains directive information (shall use an alignment monitor, shall ...) and is silent about the nature of the cooling approach, we believe the IPO really sees the type of cooling as a trade.

We therefore recommend that the dimensions of the CrIS be left open as part of the design activity and that the decision be deferred to the Phase 1 study when the IPO's views can be explicitly contributed.

Response:

Physical and interface characteristics values to remain unchanged. Weight, power, volume, and data rates described in section 3.2.4 are nominal values (with contingency) which were developed during initial studies at the Integrated Program Office. All values are defined as: (TBR), indicating that specific allocations are negotiable. It is presently planned that definitive allocations will be defined by the IPO, in consultation with sensor contractors, by the time of SRR. In the interim, contractors should keep in mind that relaxation from nominal allocations will only be possible if changes are consistent with the requirement to accommodate the full NPOESS payload suite of instruments on a spacecraft which can be placed into a nominal 833 Km orbit by an EELV class launch vehicle.

------------------------------------------------------------------ID: 2421 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 P. 37, Section 3.2.4 Physical and Interface Characteristics

Data rate

Recommendation:

The 1150 kilobits per second is too restrictive.

Rationale:

There is no loseless way to transmit the interferograms in this bandwidth which implies the interferograms will be converted to spectra prior to transmission. This requires complex high power processors, where as a modest relaxation would allow transmission of the interferograms and would perhaps, offer a lower life cycle cost.

Response:

Note that the SRD calls out the use of decimation and the use of other compression schemes. The data rate is consistent with estimates made in phase 0. Note the value is marked TBR and is subject to further study.

------------------------------------------------------------------ID: 2422 Date Recvd: 2/28/97 Status: Closed

Reference:

SRD - V2 Schedule

CrIS Flight Unit #001 Refurbishment

Recommendation:

Please clarify the required refurbishments of the protoqualification unit. Are any refurbishments other than those referenced in MIL-STD-1540B for excessive test time and potential fatigue type failures required?

Rationale:

It is possible that no refurbishments will be required pending successful protoqualifcation testing and component history review.

Response:

What ever examination and refurbishment is necessary to verify that the instrument can meet the EDR and Lifetime requirements. MIL-STD -1540 can be used as a guide. It may be that no refurbishment will be required, but that would have to be shown in some way.

------------------------------------------------------------------ID: 2423 Date Recvd: 3/3/97 Status: Open

Reference:

Section L- V2 5352.215-9014, Program Budget Profile

Contracted Budget Levels

Recommendation:

Add statement to clarify if budget profiles represent that available for the total contracted effort for each instrument suite (multiple contracts) or represent the funding available to each of the contractors.

Rationale:

At present, it is unclear if the budget levels reflect the total program or are on a per contract basis.

Response:

------------------------------------------------------------------ID: 2424 Date Recvd: 3/3/97 Status: Open

Reference:

Section M- V2 Paragraph 4.1.1 Factor 1: Performance against EDR Requirements Paragraph 4.2.5.1 Factor 1: OMPS performance EDR Requirements

Inconsistency of Paragraph 4.2.5.1 with Paragraph 4.1.1.

Recommendation:

Change Paragraph 4.2.5.1(a) to read: 'Define a conceptual design by PDR which meets the EDR threshold requirements of the OMPS SRD'

Rationale:

Paragraph 4.2.5.1 is inconsistent with Paragraph 4.1.1. Paragraph 4.2.5.1, a sub-paragraph to Paragraph 4.1.1, requires the offeror to show in the proposal how the proposed system will meet the EDR requirements.

Paragraph 4.1.1 describes a situation where the proposer must show 'an approach to meeting or exceeding EDR Requirements'; 'feasibility and viability of proposed conceptual design', 'ability of conceptual design to contribute to, or satisfy EDRs_' (Paragraph 4.1.1). This appears consistent with the intent of a proposal and the understanding that the offeror must show, by PDR, that the proposed design meets the threshold EDR requirements.

As it is currently worded, Paragraph 4.2.5.1, can be interpreted to require the offeror to show that the proposed design meets the threshold EDR requirements in the proposal. This leads to a question: If the offeror must show compliance to the EDR thresholds in the proposal, what will occur during the actual contract activity?

It is apparent in reviewing these paragraphs that Paragraph 4.2.5.1 is missing a time horizon when the proposed effort must demonstrate that it meets threshold EDR requirements.

Response:

------------------------------------------------------------------ID: 2425 Date Recvd: 3/3/97 Status: Closed

Reference:

Sensor Requirements Document, Version 2.0- V2 Paragraph 3.2.4, Physical and Interface Characteristics , SRDO3.2.4-4

Data rate specification

Recommendation:

Are the units for the specified data rate (kbps) correct.

Rationale:

Clarification

Response:

The units for the data rate are specified in kilobits per second. Please note that the actual figure for the data rate will be changed to 20 kilobits per second (TBR).

------------------------------------------------------------------ID: 2426 Date Recvd: 3/3/97 Status: Closed

Reference:

CMIS SRD- V2 Paragraphs C40.2.4-9, C40.2.4-10, C40.2.2-11, page 16

Sea Surface Temperature Measurement Uncertainty, Accuracy, Precision

Recommendation:

The present allocations for the threshold values of Measurement Accuracy is too stringent in the microwave case.

The state of the art of using microwave imagery to obtain SST data is relatively immature. To specify a .2o K Measurement Accuracy is beyond the scope of present technology and research, and thus threshold.

To an operational user who may not have the advantage of multiple passes over the same area for long periods of time, it would be more consistent to have a Measurement Accuracy of .2o K when accompanied with a Measurement Precision of, say, .1o K, vice .5o K. Again, this would be pushing the threshold too far. A better allocation of variability would be an accuracy of .5o K and a precision of .2o K, or just a Measurement Uncertainty of .5o K.

Rationale:

Recommend paragraphs C40.2.4-10 and C40.2.4-11 be deleted or N/A ed.

Response:

As defined in the current TRD, "measurement accuracy" is the bias or mean in a measurement sequence and "precision" is the standard deviation. The current operational infrared (IR) Sea Surface Temperature (SST) algorithm has a 0 (zero) mean error (bias), and standard deviation around 0.38K. The IPO examined the current retrieval algorithm by performing ~20,000 Monte Carlo runs of different model atmospheres and input sea surface temperatures to get this answer. As a result, and given the TRD definitions, we believe an accuracy threshold to 0.2K, and the precision threshold to 0.5K are achievable. (Of course this applies to the current algorithm, which is IR not microwave.) We do not know what the performance will be achieved with a microwave SST algorithm, but since the HSR size is 50 km, you can get a lot of averaging, perhaps making it possible to reach the 0.2K accuracy. In any event, the threshold values for Measurement Accuracy and Measurement Precision have been revised to TBD in the CMIS SRD to allow for further examination of this issue.

------------------------------------------------------------------ID: 2427 Date Recvd: 3/3/97 Status: Closed

Reference:

Cover Letter- V2 Paragraph 3

Comments on FFP

Recommendation:

The implication of FFP on the risk reduction/preliminary design phase of the program is to have FFP during the detailed design phase. Due to the interactions and design tradeoffs with the spacecraft supplier during this phase, FFP is not practical. We have discovered in dealing with NASA and NOAA that FFP for technology insertion activities reduces the customer interaction and full IPT participation. We recommend that the risk reduction/preliminary design phase be CPIF and the detailed design phase be CPAF. FFP for production is very viable.

Rationale:

Response:

The contract type will remain as CPFF.

------------------------------------------------------------------ID: 2428 Date Recvd: 3/3/97 Status: Closed

Reference:

GPSOS SRD, version 2.0- V2 Paragraph SRDG 3.1.6.2.3-7, page 14 and Paragraph 3.2.1.1.3.1.1, page 17

Electron Density Profiles and Total Electron Content

Recommendation:

In page 17, it is given that profile measurements above the NPOESS altitude are not required.

Rationale:

Recommend that the following be added in page 17 for clarity. "The GPSOS data shall also be used to produce observations of TEC above the NPOESS altitude using data from the non-occulting GPS satellites."

Response:

Accept.

------------------------------------------------------------------ID: 2429 Date Recvd: 3/3/97 Status: Closed

Reference:

GPSOS SRD, version 2.0- V2 Table 3.1.1.1 page 9

GPSOS Sensor Characteristics

Recommendation:

In this table 2nd column heading "RT Navigation e)" be corrected to

"RT Navigation d)".

Rationale:

Footnote e) does not exist.

Response:

Corrected.

------------------------------------------------------------------ID: 2430 Date Recvd: 3/3/97 Status: Closed

Reference:

Section L- V2 Paragraph 2.1.1

Proposal Delivery Information

Recommendation:

Past Performance is due 15 days prior to the submission of the proposal. Is this submission to be made in paper form, electronic form, or both? Additionally, if the submission is to be made in electronic form, then the contractor should be able to perform tests in accordance with Paragraph 2.3.3 Proposal Test Period in time to take any corrective actions required.

Rationale:

Delivery instructions for the Past Performance are unclear. Please note that the response to this comment/question needs to be available prior to the final Request for Proposal due to the short proposal response time from that date and the testing time described above.

Response:

The past performance volume should be submitted in both paper and electronic form. The Volume IV will be separated from the basis proposal and submitted 15 days prior to the deadline for proposal submission. The government will test the files from 26 - 28 Mar 97.

------------------------------------------------------------------ID: 2431 Date Recvd: 3/3/97 Status: Closed

Reference:

Section L- V2 Paragraph 2.2.3

Foldouts

Recommendation:

Margins, as specified in Paragraph 2.2.2 are defined as ". . .3/4 inch margins on all sides. . .". Paragraph 2.2.3 states that the image size is 9 by 15 1/2. Should the image area be 9 1/2 by 15 1/2 in order to be consistent with 3/4 inch margins rule?

Rationale:

Consistency with Paragraph 2.2.2. A rapid response to this comment/question is necessary to support the submittal of the proposal in a timely manner.

Response:

Yes. The margins will be changed to 9 1/2 by 15 1/2.

------------------------------------------------------------------ID: 2432 Date Recvd: 3/3/97 Status: Closed

Reference:

Section L, Section M- V2 Section L: Paragraph 3.2.1.4.1 (Section L)

Section M: Paragraph 4.2.3.4, Subparagraph a)

Inconsistency of Paragraph 4.2.3.4 with Section L Paragraph 3.2.1.4.1

Recommendation:

Evaluation standard in Section M, Paragraph 4.2.3.4, subparagraph a) seeks a discussion on IR radiance values required to produce various EDR's. Section L calls for the identification of mission critical components. These elements, along with others in this area appear to be inconsistent.

Rationale:

Consistency in requirements of Section L to the evaluation standards in Section M are necessary for uniformity in the evaluation of proposals.

Response:

Within the discussion for Chapter 4 - Sensor and Sensor Subsystem Design, the offeror should address the items listed under Section L para 3.2.1.4. The government will use the criteria listed in Section M, para 4.1.4 to evaluate the proposal. It is these criteria that should be consistent with the requested discussion. The standards listed in Section M, para 4.2.3.4 a(1)(2) are what the government feels should be in the discussion to evaluate whether the proposal met the requirements satisfactorily for that criteria.

------------------------------------------------------------------ID: 2433 Date Recvd: 3/3/97 Status: Closed

Reference:

Section L-2- V2 Paragraph 2.3.5.2 (Page 203/4)

File Directory 1 -- Proposal Information (Note at end of table)

Recommendation:

Clarify the page limit for the past performance volume by changing last entry in the table and asterisk note below the table as follows: Remove the "20" from the table and leave the "*". Change the note to read: "* The narrative portion of the volume (sections 2, 3, and 4) are limited to twice the number of contracts (prime + subcontractor) discussed in the volume. The total number of pages in the entire volume shall not exceed 20 pages."

Rationale:

The current table entry and note are confusing, and the answer to RFP Comment #1817 conflicts with the current note. The main difficulty is that the interpretation of which sections are included in the definition of the "narrative portion" is confusing. A rapid response to this comment/question is necessary to support the early submittal of the Past Performance volume in accordance with the requirements of the draft RFP.

Response:

The page limit for the past performance volume was changed. The only limit applies to the narrative portions (Sections 2, 3, 4) with the pages limited to twice the number of contracts discussed in the volume. There is no limit on the total number of pages nor the number of contracts.

------------------------------------------------------------------ID: 2434 Date Recvd: 3/3/97 Status: Closed

Reference:

Section M- V2 Paragraph 4.1.1, Factor 1: Performance against EDR Requirements

Paragraph 4.2.1.1, Factor 1: VIIRS Performance against EDR Requirements

Recommendation:

Inconsistency of Paragraph 4.2.1.1 with Paragraph 4.1.1

Rationale:

Change Paragraph 4.2.1.1(a) to read: 'Provides complete and credible substantiation that, by PDR, the proposed conceptual design and algorithms meet (or exceeds, if applicable) all threshold requirements of the VIIRS primary EDRs as given in the VIIRS SRD for a broad and representative range of environmental conditions.'

Response:

Paragraph 4.2.1a was changed to clarify what is expected.

------------------------------------------------------------------ID: 2435 Date Recvd: 3/3/97 Status: Closed

Reference:

SRD- V2 VIIRS SRD

40.7.11.6 Accuracy; Mass Loading: 30%

Recommendation:

Reduce this accuracy requirement to 50%.

Rationale:

The accuracy requirement for Mass Loading and Littoral Sediment Transport should be the same.

Response:

Reject. EDRs reflect customer products and there is no requirement for consistency between EDRs. If two EDRs require measuring the same physical phenomena, then the more stressing EDR is the driving requirement.

------------------------------------------------------------------ID: 2436 Date Recvd: 3/3/97 Status: Closed

Reference:

- V2 Comments on CPFF versus FFP

Recommendation:

We recommend the CPFF contract type to FFP for this phase of the program. There are advantages and disadvantages to both contract types but we feel that the IPPD/IPT process is best served in a CPFF environment. The following table is our attempt to view a FFP contract from a government perspective.

Advantages: Less Cost Risk, Less government oversight resources required, Competitive Environment/Adequate Motivator, Potential "buy-in" by large Aerospace companies

Disadvantages: Reduced visibility into cost, Degraded IPT environment - tendency for buck passing instead of stepping up, No assurance that buy in will result in lower LCC, Encourages conservative designs/limits trade-offs, Difficult to implement multifunctional, empowered, and responsible teams, Establish walls between government and industry, Lead to more change proposals, Reduced flexibility

Rationale:

Response:

The contract type is planned to be CPFF.

------------------------------------------------------------------ID: 2437 Date Recvd: 3/3/97 Status: Closed

Reference:

5352.243-9000 - V2

Advance Change Adjustment Agreement

Recommendation:

In the original draft RFP, a $25,000 limit per change was established; this has been increased to $500,000. This is an extraordinarily high limit.

Rationale:

Confirm is this reference is correct, as a $50,000 limit may have been what was intended.

Response:

The value of $500,000 represents an editorial error in the DRFP. The intended value was $50,000. The clause will be revised for the final RFP.

------------------------------------------------------------------ID: 2438 Date Recvd: 3/3/97 Status: Closed

Reference:

Appendix II-E - V2 Section L, 3.2.3.5

Make or Buy Plan

Recommendation:

Is the Make Buy Plan required for the risk reduction phase only or for all program phases?

Rationale:

Recommend process description for all phases of program and specific plan through PDR.

Response:

The Make or Buy Plan is required for the total program. Most the details and specificity will certainly be for the risk reduction phase. However, the government is also interested on how the offeror intends to make production make or buy decisions and the processes to be followed after PDR thru delivery.

------------------------------------------------------------------ID: 2439 Date Recvd: 3/3/97 Status: Closed

Reference:

CLIN - V2 0003, 0007, 0018, 0022, 0033, 0037, 0046, 0050

Direct Material and ODC

Recommendation:

These CLIN's direct material and ODC for the risk reduction studies. However, the material and ODC will be developed for the systems design task.

Rationale:

Recommend that these CLIN's be changed to support the system design and development CLIN's, 0001, 0005, 0016, 0020, 0031, 0035, 0044, 0048.

Response:

The ODC and direct materials associated with design effort up to PDR is distinct from the ODC and direct materials in the referenced CLINs. The risk reduction studies are separate special studies from the design effort and are included in two separate CLINs. The first CLIN has hours as the deliverable, and the second CLIN has the associated direct material and ODC related to these special studies. These studies will be incorporated into the contract only by unilateral direction by the PCO and are include additional effort above and beyond the effort included in the definition and design CLINs.

------------------------------------------------------------------ID: 2440 Date Recvd: 3/3/97 Status: Closed

Reference:

CLIN Delivery Schedule - V2

Recommendation:

CLIN 0051 schedules protoflight unit delivery for OMPS only 1 Apr. 04. Section L, Paragraph 1.8 schedules protoflight unit delivery for 1 April 02.

Rationale:

Recommend that the CLIN be changed, consistent with Section L.

Response:

The schedule is correct. The first unit available for OMPS is 1 Apr 02 and is Flight Unit #2 (CLIN 054). The protoflight unit is the first unit tested at the protoqualification levels. This unit is assumed to need some refurbishment and will be delivered later on 1 Apr 04 since it is not the first flight unit available.

------------------------------------------------------------------ID: 2441 Date Recvd: 3/3/97 Status: Closed

Reference:

CMIS Technical Evaluation Standards - V2

Recommendation:

The following inconsistencies between Section L & Section M may make it difficult to evaluate proposals.

Rationale:

Section M (4.1.4), Factor 4e: This factor appears to be more appropriate to Chapter 3.

Section M (4.2.2.4), Factor 4a: This standard appears to be more appropriate to Chapter 1 and Factors 4b, 4h: those standards appear to be more appropriate to Chapter 1.

Response:

Section M, Para 4.1.4e asks for the integration and test planned for the sensor and whether it is adequate. This matches with Section L, Para 3.2.1.4.4. This factor is appropriate as is. Section M, para 4.2.2.4a and h were deleted. Para 4.2.2.4h is appropriate for this factor since it asks whether the offeror demonstrates their understanding of actual sensor design versus the basic systems engineering processes.

------------------------------------------------------------------ID: 2442 Date Recvd: 3/3/97 Status: Closed

Reference:

Draft RFP #2 - V2 Annex B

IMP/IMS Instructions

Recommendation:

Draft RFP #2 still contains some ambiguity with respect to the "tasks portion of the Integrated Master Plan (IMP). Is the IPO looking for a completely separate section within the IMP listing summary level tasks that read somewhat like a Statement of Work? Or is the IPO looking for a separate listing of the detailed tasks that would normally be added (and networked) into the IMP (one or more levels below the Accomplishment Criteria) to create an Integrated Master Schedule (IMS)? Or is the IPO looking for a separate listing of tasks augmenting (at the same level?) the usual Event, Accomplishment, Criteria structure of an IMP (recognizing that most accomplishments and criteria are in fact tasks stated as having been completed)? An outline and/or an example of what is expected in the IMP would also be very helpful.

Rationale:

Adding separate task statements to an unfamiliar variation of the usual structure and content of an IMP. More guidance on what is expected will prevent inappropriate responses by the offerors.

Response:

The government is looking for a completely separate Task section within the IMP, listing summary level tasks that read like a Statement of Work. The tasks should be traceable to the WBS elements.

------------------------------------------------------------------ID: 2443 Date Recvd: 3/3/97 Status: Closed

Reference:

Paragraph 3.4.3 - V2 Section L2

Recommendation:

It appears that Sections 3.4.4 and 3.4.5 of Section L-2 were inadvertently omitted. Is this correct.

Rationale:

Paragraph numbering appears out of sequence.

Response:

No sections were omitted. Paragraph 3.4.6 will be renumbered to 3.4.4.

------------------------------------------------------------------ID: 2444 Date Recvd: 3/3/97 Status: Closed

Reference:

Section L2 - V2 Paragraph 2.3.5.2

Recommendation:

Clarify the Past Performance Volume page allocation. The explanatory note at the bottom of the table showing page counts is subject to interpretation. Please specify the number of contracts allowed and the page allocation for the narrative and contracts sections.

Rationale:

Clarification of page count.

Response:

The only page limitation is for the narrative portions (Section 2, 3, 4) and will be limited to twice the number of contracts cited. For example, if the offeror cites 14 contracts, Sections 2, 3, and 4 are limited to 28 pages. There is no limit for Sections 1 or 5.

------------------------------------------------------------------ID: 2445 Date Recvd: 3/3/97 Status: Closed

Reference:

Section M - V2 Paragraph 5.1 (a)

Recommendation:

Factor 1 (a) includes the statement "(including co-location of key personnel and resources)". Is there a requirement for co-location or is an efficient electronic network a viable alternative.

Rationale:

Co-location is desirable but electronic communications can achieve efficient team interaction.

Response:

There is no requirement for co-location of personnel or resources. Although for separately located personnel, it is more important for the government to understand the offeror's management approach.

------------------------------------------------------------------ID: 2446 Date Recvd: 3/10/97 Status: Open

Reference:

Annex A - V2 Sensor WBS, F04701-96-R-0012, Page 5 of 10

Recommendation:

Issue: a) Is WBS 1.3 - 1.n intended to specify different sensors

within the same suite (such as potentially separate mapping and

profiling sensors within OMPS)? If so, where should common hardware

and/or activities be accounted for? As a separate 1.x, or within one

of the sensors?

Issue b) Is all risk reduction activity leading to PDR to be

proposed under WBS 1.1 and 1.2, or are some pre-PDR task elements to

be proposed under WBS 1.3 - 1.n? Items such as systems engineering,

preliminary design, and development hardware could all be interpreted

to have some pre-PDR task activity.

Rationale:

Response:

------------------------------------------------------------------ID: 2447 Date Recvd: 3/10/97 Status: Closed

Reference:

OMPS SRD - V2 Version 2.0, 3.2.4, Page 21, Physical and Interface haracteristics

Recommendation:

Issue: SRDO3.2.4-4 requires an OMPS data rate of less than or equal

to 1.0 kbps (TBR)

Section 3.2.4.8.6, Low Rate Science Data, page 38, seems to permit data

rates less than 100 kbps over the 1553 data bus. The specified 1.0

kbps, if governing, would severely limit the OMPS trade space of

potential sensor configurations - since mapping and profiling could

easily each consume 10 kbps with some on-board processing and mandated

RDR overhead and CCSDS formats. Please clarify whether the stated 1.0

kbps is the government's actual goal for OMPS (or a typo), or whether

data rates up to the 100 kbps called out in 3.2.4.8.6 should be

included in the proposed trade space.

Rationale:

Response:

The notional data rate for the OMPS was based on early studies done for the IPO. These early studies assumed a design with lower projected capability than the current OMPS, thus the lower data rate. The data rate for OMPS will be changed to 20 kbps (TBR). Note that this is not a hard number. Interaction between the IPO and contractors is expected/encouraged to determine the optimum data rate.

------------------------------------------------------------------ID: 2449 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 1.2. p1

Recommendation:

a) #1) Required position and time accuracy seems difficult to meet for a stand alone receiver. Is NPOESS a PPS user?? P(Y)- code available??

b) L5 at 1140 Mhz...is the frequency really established? This additional frequency puts tough filter requirements on the RF/IF front end (selectively, noise) since GNSS L2 band need to be wider.

Rationale:

Response:

a) Yes, P(Y) code is intended to be available and is required to meet the specified accuracy's.

b) The SRD has been revised to use potential future availability of L5 as a Pre-planned Product Improvement option if and when it becomes available. The baseline GPSOS sensor performance requirements require the use and processing of L1 and L2.

------------------------------------------------------------------ID: 2450 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 3.1.1.p7

Recommendation:

a) 5200 occultation events per 24 hours for 3 satellites implies an average of 1733 per satellite. the GRAS/MetOp-1 mission analysis gives significantly lower numbers, depending on the occultation antenna beam shape - which in turn is influenced by the gain required to over come the atmospheric attenuation/defocussing phenomena at lower tangent point altitudes. Numbers may be in the range 1200 to 800 per 24 hours - still being evaluated.

Rationale:

Response:

a) The 5200 number comes form orbital analysis of the maximum possible occultation events (GPS and GLONASS) over a 24 hour period. The actual number of occultations measured by the GPSOS is TBS, with a goal of measuring all possible occultations. [PRS: Delete the following sentence - Use of the L1 and L2 offers a significant enhancement in the receiver's SNR and this factor should be fully exploited in the sensor trade space.]

------------------------------------------------------------------ID: 2451 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 3.1.1.1-1.p7

Recommendation:

a) The received power level -130 dBM using a 0 dBi RHCP antenna can only be accomplished without atmospheric attenuation. In the real occultation scenario the required antenna gain may be as high as +15 dBi to have a signal power level of _134 dBM worst case.

b) "GPSOS Antenna design minimizes these multipath... LHCP shall be rejected by an additional 20dB:. We interpret this so that the antenna alone should have a cross polarization suppression of at least 20 dB in the angular coverage regions of interest.

Rationale:

Response:

Agreed. The specified power level of -130 dbm is provided as an estimate of the signal level required in the absence of the effects of atmospheric defocusing. The contractor analysis should assess the effects of deviations from this specification on the sensor ability to meet noise requirements for phase and pseudorange measurements associated with tropospheric occultations.

a) Primarily, the GPSOS sensor is intended to produce the electron profile EDR of the ionosphere where both the sensor and associated algorithms are well understood. The same sensor is expected to yield measurements supporting tropospheric characterization, i.e. secondary EDRs. Primary EDRs are designated as such because of relative uncertainty in the development status of the associated processing algorithms. Also see ANS to Section 3.1.1 above (ID# 2450). (Continuing monitored by the IPO)

b) Agree

------------------------------------------------------------------ID: 2452 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-6

Recommendation:

a) GPS time? For UTC only 1 microsec can be guaranteed.

Rationale:

Response:

a) GPS P(Y) code receivers support a 100 ns accuracy. The enhanced accuracy is desired in order to support co-registration of other sensor data, primarily sounders and imager sensors also currently under development by IPO.

------------------------------------------------------------------ID: 2453 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-9

Recommendation:

a) The basic number of channels appear to be 26 to 28, with possible increase for L5 (1140 Mhz). By using a state-of-the-art channel processor ASIC it ends up with (2.5W*7) about 18W for the channel processing ASICs only.

Rationale:

Response:

a) The sensor power requirement allocation is designated as TBR in the revised SRD and should be included as one of multiple factors in an overall sensor design trade space.

------------------------------------------------------------------ID: 2454 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-11

Recommendation:

a) 50 Hz sample rate is sufficient from a user point of view.

Rationale:

Response:

a) Disagree. The selectable 100 Hz sampling rate comes about to redress a design limitation in the GPS-MET program and to support neutral atmosphere soundings close to the earth's surface, even during high rain rate events.

------------------------------------------------------------------ID: 2455 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-12

Recommendation:

a) Selective Availability will be removed by differential GNSS. Anti Spoofing (Y-code enabled) Implies codeless tracking techniques. Implemented in the channel processor ASIC for GRAS.

Rationale:

Response:

a) Simultaneous processing of L1 and L2 (encrypted) is required to support the positional accuracy and time requirements.

------------------------------------------------------------------ID: 2456 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-13

Recommendation:

a) Plus/minus 90 degrees of the velocity vector is too wide a coverage zone, to achieve sufficient Antenna gain (>10dBi). Most likely the limitation will be less than plus/minus 45 degrees in azimuth.

Rationale:

Response:

a) See answer to section 3.1.1 above (ID# 2450). The intent of the SRD is to maximize the number of observed occultations and not to pre-ordain a specific antenna implementation. This issue should be addressed as part of the overall sensor system trade space.

------------------------------------------------------------------ID: 2457 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-14

Recommendation:

a) Calibration possibilities and needs are presently being considered within the GRAS study.

Rationale:

Response:

a) None required.

------------------------------------------------------------------ID: 2458 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-16

Recommendation:

a) The actual probabilities depend very much/likely on the characteristics of the atmosphere through which the ray passes. Too early to specify numbers. Definition of acquisition, needed.

Rationale:

Response:

a) Acquisition accomplished when the sensor SNR > 3 dB for the occultation signal.

------------------------------------------------------------------ID: 2459 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-17

Recommendation:

a) GPS ICD 203 and 207 not available.

Rationale:

Response:

a) These documents will be made available after award.

------------------------------------------------------------------ID: 2460 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.1.1-19

Recommendation:

a) Power consumption is under estimated. By using a state-of-the-art channel processor ASIC, it ends up with (2.5W*) about 18W for the channel processing only.

Rationale:

Response:

a) See answer to Section 3.1.1.1-9 above (ID# 2453).

------------------------------------------------------------------ID: 2461 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 Table 3.1.1.1

Recommendation:

a) Troposhere 100 Hz sample rate not compatible with 1 sec carrier precision. Please clarify by rephrasing. 50 Hz sample rate sufficient from a user point of view.

b) Carrier phase precision for the Troposhere/Stratosphere can be relaxed from a user point of view. Remember also the technical problems due to the decreased SNR at low altitudes and the wider PLL BW due to higher sample rate (more noise).

c) Pseudorange position: For GPS or GLONASS??

Rationale:

Response:

a) See answer to Section 3.1.1.1-11 above (ID# 2454).

b) Part of the sensor developer's trade space for instrument design.

c) Both.

------------------------------------------------------------------ID: 2462 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.6.2.3-1. p13

Recommendation:

a) 60 days operation without additional commands. Why? (National security reasons?)

b) "The GPSOS Sensor sample rates are selectable by ground control....in four atmospheric regimes..." A change in the sample rate during an occultation must be controlled autonomously by the receiver since the ground station does not have a continuous contact with the space vehicle. Whether a sample rate change without loosing track is feasible or not is under consideration within the GRAS study.

Rationale:

Response:

a) Requirement revised to 21 days without additional commands, with 60 days listed as a "goal" to ensure uninteruppted service despite natural or manmade disturbances such as fire, flood, tornado at a ground station.

b) The sample rate is "commandable" from the ground or programmable for predicted occultation events.

------------------------------------------------------------------ID: 2463 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.6.2.3-4. p13

Recommendation:

a) The GPSOS contractor is responsible for producing EDRs (Environmental Data Records) from the GPSOS Sensor's RDRs (Raw Data Records). Really? See also SRDG3.1.6.2.5-6, 1)

Rationale:

Response:

a) For Electron Density Profiles/Ionospheric Specification, the contractor is responsible for both the sensor and the science algorithm for producing the EDR.

------------------------------------------------------------------ID: 2464 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.6.2.3-6. pp13-14

Recommendation:

a) The GPSOS contractor can take no responsibility for the accuracy of the c.o.m. location. The antenna characteristics will be referred to the mounting interface and to a specific RF environment.

Rationale:

Response:

The GPSOS Sensor vendor(s) shall be responsible to work with and fully integrate the sensor (and all its components, including support antennas) into the prime contractor's overall spacecraft design and implementation to assure that the sensor will perform on orbit.

------------------------------------------------------------------ID: 2465 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 SRDG 3.1.6.2.4-2. p14

Recommendation:

a) Text appears to be missing before "The GPSOS Sensors operate..."?!

Rationale:

Response:

a) Revised.

------------------------------------------------------------------ID: 2466 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 3.2.1.1.1. p15 (16 in some printouts)

Recommendation:

a) scientific algorithm responsibility - should rest with the scientific community which are to use the data.

Rationale:

Response:

a) Reject. NPOESS requirements are for operational environmental data record products. The GPSOS sensor contractor must demonstrate that the sensor design can satisfy the EDR requirement levied on that sensor and is therefore responsible for developing the science algorithm for that EDR.

------------------------------------------------------------------ID: 2467 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 3.2.1.1.3.1.1 and 3.2.1.1.3.1.2 on ionospheric observations:

Recommendation:

a) To be discussed in general.

b) TEC integrated above GPS altitude although profile measurement above NPOESS altitude is not required?! Somewhat confusing.

Rationale:

Response:

a) None required.

b) Issues clarified in revisions to SRD's text. Profile measurements above the NPOESS altitude are not required. However, the GPSOS sensor data from non-occulting satellites will be used to produce slant path TEC observations of the topside/plasmasphere.

------------------------------------------------------------------ID: 2468 Date Recvd: 3/12/97 Status: Closed

Reference:

GPSOS SRD - V2 3.2.5.1 Reliability <0.86 for 7 years

Recommendation:

a) To be investigated - MetOp-1 requires 0.80 if possible without redundancies. (Compare SRDG3.1.1.1-18... no single point failure allowed....)

Rationale:

Response:

a) This has been revised to state that no single point failures in electronic components. This is an operational system with long lifetime.

------------------------------------------------------------------ID: 2469 Date Recvd: 3/14/97 Status: Closed

Reference:

IRD, V2, dtd 2/21/97 3.2.4.1

Spacecraft Temperature Range

Recommendation:

"a. 5 deg C (TBR) to +40 deg C during normal operations" the first number should be much lower; maybe " - 10 deg C (TBR) - - - ".

Rationale:

Although the given range may apply for many cases, it doesn't fit all conditions of location and sun angle. The payload equipment should be designed to operate properly over a larger recommended temperature range to allow sufficient flexibility and margin in the spacecraft payload accommodations.

Response:

This will be one area that will be resolved during the course of this contract as reflected with the TBR designation.

------------------------------------------------------------------ID: 2470 Date Recvd: 3/14/97 Status: Closed

Reference:

IRD, V2, dtd 2/21/97 3.3.2.1

Primary Sensor Voltage

Recommendation:

Recommend changing 28ñ1V to 28ñ6V.

Rationale:

Even tho there is a TBR noted, It might be better for the sensor contractors to plan for the worst case. It would have less sensor impact to change to a tighter tolerance than a looser tolerance at a later date.

Providing a 28ñ1VDC 'regulated bus' in the spacecraft requires some form of electronic regulation equipment; whereas 28ñ6VDC takes advantage of the normal range of battery regulation during sun and eclipse operation. The latter provides the highest level of reliability for the payload and spacecraft power. The payloads require their own conversion power supplies, in any case, to develop other voltages (e.g., 5V dc) for internal use.

An earlier reply to this question indicated an advantage to the sensor in EMI/EMC design, which may be valid; but there are numerous satellite systems that have have been successfully meeting EMI/EMC requirements using 28ñ6V bus for many years and is still the design of choice for many new programs. Some of these same type sensors are planned for the EOS Common Program; which is 28+7/-4VDC (as specified in the NASA GSFC EOS Common GIRD).

Response:

------------------------------------------------------------------ID: 2471 Date Recvd: 3/14/97 Status: Closed

Reference:

IRD, V2, dtd 2/21/97 3.9.1

Sensor Fairing Dynamic Envelopes

Recommendation:

The dimensions in Fig 6 (b) should be revised to represent the latest Delta 10L payload fairing. The dimensions 80 and 144 should be replaced with 82 and 201 inches, respectively.

Rationale:

McDonnell Douglas is replacing the aluminum fairing with a "10L" Graphite Epoxy fairing with a much longer straight section in concert with the additional boost capability to accommodate larger satellites.

Response:

The figure in the IRD do not represent any current launch vehicle fairing. These are projected fairing sizes for the EELV Medium Launch Vehicle class. The dimensions remain as is.

------------------------------------------------------------------ID: 2472 Date Recvd: 3/14/97 Status: Closed

Reference:

IRD, V2, dtd 2/21/97 3.9.8

Acceleration Load Factors

Recommendation:

Recommend a qualification level of ñ7 g in all three axis.

Rationale:

Recommend that the sensors be qualified to a slightly larger generic acceleration level to include all MLV boosters and be capable of any spacecraft mounting orientation.

Response:

Your recommendation will be taken under consideration. The values shown in fig. 8 of the IRD and fig. 3.2.6.2.3 of the SRDs are based on the best information we have at this time. If you believe you have better or more recent information we would like to see it. This is an item that can be discussed in the Interface Control Working Group that the IPO intends to set up.

------------------------------------------------------------------ID: 2473 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part I - THE SCHEDULE- V2 page 151, Section H, subparagraph (2)

5352.219-9001 (JULY 1992)--AFMC FAR SUPPLEMENT

Recommendation:

As discussed in ID: RHH-02, above, the Individual Plan and its goals and reporting requiremens for this Clause would be superseded by the Comprehensive Plan.

Rationale:

Response:

The goals included in the clause in the second Draft RFP have been deleted in the final RFP and will be inserted in the definitive contract, based on the results of discussions.

------------------------------------------------------------------ID: 2474 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part I - V2 page 151, Section H, subparagraph (2)

5352.243-9000 (JULY 1992)--AFMC FAR SUPPLEMENT

Recommendation:

Given the IPO's recent answer to original questions/comments regarding this clause, it is being considered in "a new light". However, the change in Version 2 of the DRFP, from $25,000 to $500,000 seems to be a "typo". Please advise.

Rationale:

$500 K, if not a "typo" would be a prohibitive level to consider for "no-change in negotiated cost or fee" transactions.

Response:

The $500K amount represented a typographical error. The correct amount of $50K has been incorporated into the final RFP.

------------------------------------------------------------------ID: 2475 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II - V2 page 159, Section I, (1), I.

FAR 52.245-19 (APR 1984)

Recommendation:

It is our understanding of the authorizing provision at FAR 45.308-1, that the Clause at 52.245-19 is not authorized for cost reimbursement contracts. Finding this Clause under the first grouping of Clauses, i.e., "The following set of clauses applies to all CLINS." appears to be incorrect. Please advise.

Rationale:

Response:

The clause has been relocated from the subset of clauses applicable to all CLINs to those applicable to the fixed-price (FPIF) option CLINs.

------------------------------------------------------------------ID: 2476 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II - V2 page 160, Section I, (1), I.

FAR 52.11-11 (APR 1984)(In the blank in paragraph (a) insert "$TBD")

Recommendation:

Given the nature of this procurement, the acquisition of R&D space instruments, the inclusion of a liquidated damages provision creates a financial risk critically disproportionate to the degree of unknowns and uncertainties associated with the development and delivery of such instruments. It is requested that this provision be deleted.

Rationale:

In effect, the inclusion of this cost prohibitive provision -- to protect against cost growth to the customer due to development, assembly and/ or I&T anomalies produces the very result to be avoided.

Response:

At this time, the program office believes the use of this clause is appropriate for the fixed-price option CLINs, if exercised. The risk associated with development should be sufficiently mitigated by the fabrication of the fourth or fifth flight units, when the CLIN type will shift to FPIF and this clause would be apply. Note that this portion of the effort will not be priced until the CFI.

------------------------------------------------------------------ID: 2477 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II - V2 page 160, Section I, (1), I.

FAR 52.245-2 (DEC 1989) ALTERNATE I (DEV) (JUL 1995)

Recommendation:

We are unable to locate a copy of the Alternate I Deviation. Is it possible for the PCO for forward the text of this material, perhaps via e-mail. Your assistance here would be greatly appreciated.

Rationale:

Response:

The clause may be found through the Air Force's FAR site on the World Wide Web at the following URL: http://farsite.hill.af.mil.

------------------------------------------------------------------ID: 2478 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II - V2 page 160, Section I, (1), I.

FAR 52.246-18 (APR 1984)

Recommendation:

The inclusion of this optional clause would require a prohibitive level of finanical protection for the contractor, again, producing the result to be avoided by both parties. Although the clause contemplates supplies of a "complex nature", the NPOESS Sensors are not comparable to complex, field reparable/replaceable avionics modules, for example. The application of this clause is not suited to the pending procurement; therefore, it is requested that the clause be deleted.

It was noted in reviewing the instructions for detailing the clause that the requirement to insert "45. . . " in paragraphs (b) and (d) seems to be in error. It is believed that such insertions would be made in paragraph (c) (3). (We still request, though, that the clause be deleted.)

Rationale:

Response:

At this time, the program office believes the clause is applicable. Note, however, that the clause applies to the fixed-price options CLINs for the fabrication of flight units to be priced at CFI. The clause is not applicable to the first phase of the effort to be awarded and the issue can be revisted prior to issuance of the CFI.

------------------------------------------------------------------ID: 2479 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II-CONTRACT CLAUSES - V2 page 157, Section I, (1), I.

FAR 52.203-9 (SEP 1995)(FAC90-30)

Recommendation:

It is our understanding, per FAC 90-45, dated 2 Jan 97, that the actual certification requirements have been deleted. Given this, it is assumed that the subject Clause will be deleted in the formal RFP. Please advise.

This deletion would also be noted in the Section K Certifications and Representations, page 174, cited as 52.203-8 [should be 52.203-9].

Rationale:

Response:

Subject clause was deleted from the final RFP, in accordance with FAC 90-45.

------------------------------------------------------------------ID: 2480 Date Recvd: 3/14/97 Status: Closed

Reference:

RFP Part II-CONTRACT CLAUSES - V2 page 158, Section I, (1), I.

FAR 52.219-9 (AUG 1996)(FAC 90-30); and FAR 52.219-16 (OCT 1995)(FAC 90-30).

Recommendation:

This Company is currently engaged in a Pilot Program with DoD, whereby the Corporate ACO and the Company have entered into an agreement that, during the period of the Pilot Program, supercedes the 52.219-9 and -16 individual contract Plan and reporting requirements, as well as the individual contract Liquidated Damages provision. This Comprehensive Plan is structured at the consolidated corporate level, with goals and reporting established at that level by the ACO and the Company. Periodic reporting is provided directly to the ACO, on a total corporate basis. With appropriate evidence of an approved Comprehensive Plan in place, it is assumed that 52.219-9 and 52.219-16 will be deleted in the pending NPOESS contract, for this Company. Please advise.

Rationale:

Innovative, Acquisition Reform at work for both parties.

Response:

Please include this information in your proposal and the Government will consider it.

------------------------------------------------------------------ID: 2481 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.5.1, Page 202

CD-ROM Root Directory

Recommendation:

Hypertext links are required from the Table of Contents (TBLCONT.PDF) located in the root directory. Are they also required from each of the tables of contents located in File Directories 1 and 2?

Rationale:

Response:

Yes. Hypertext links are also required from the tables of contents in Directories 1 and 2. Para 2.3.5 will be amended.

------------------------------------------------------------------ID: 2482 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 1.2, Page 199

Oral Presentations

Recommendation:

Will the oral presentation be interactive with the customer asking questions during the 1-hour time limit, or will questions be asked only after the presentation?

Rationale:

Presentation structure

Response:

Questions for clarification only will be allowed after the presentation.

------------------------------------------------------------------ID: 2483 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 1.2, Page 199

Oral Presentations

Recommendation:

We would like to present using 2 vugraph projectors and 2 screens with the presenter standing between the screens. Will the customer provide 2 vugraph projectors and 2 screens for our presentation?

Rationale:

Presentation structure

Response:

Audio-visual equipment needs should be coordinated with Mr Dave Furlong, (301) 427-2084, ext 160 or Lt Tim Bode, (301) 427-2084, ext 174.

------------------------------------------------------------------ID: 2484 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.5.2, Page 203

File Directory 1 - Proposal Information (Oral Presentation)

Recommendation:

Required file names for each of the files submitted electronically are provided except for the Oral Presentation. It should be in PDF format if it will be viewed by evaluators.

Rationale:

Response:

The oral presentation file should be named ORAL.PDF.

------------------------------------------------------------------ID: 2485 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 1.2, Page 199

Oral Presentations

Recommendation:

Please provide a diagram of the room in which the oral presentation will take place; including room dimensions, the seating arrangement for attendees, number of attendees, and placement of the vugraph projector(s) and screen(s).

Rationale:

The oral presentation will be more effective if we are aware of the arrangements before the day of presentation.

Response:

The offerors will have a half hour prior to the presentation to set up the conference room as they see fit.

------------------------------------------------------------------ID: 2486 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Sections 2.3.5.2 and 2.3.5.3, Page 203 and 204

File Directories 1 and 2

Recommendation:

Will all files required in directories 1 and 2 be viewed in Adobe Acrobat and evaluated electronically? If so, should they all be submitted in PDF format?

Rationale:

We are told by Adobe that files submitted in Excel spreadsheets (*.XLS) and MS Word (*.DOC) cannot be linked to the master table of contents (TBLCONT.PDF) located in the root directory. If the evaluators wish to view those documents, they should also be submitted in *.PDF format.

Response:

The government has used Adobe Acrobat Exchange on other programs and were able to link a Word document or an Excel spreadsheet to a PDF document (e.g. Table of Contents). The Create Link tool allows one to open up a PDF document or open other applications with hypertext links. There is no need to specify a PDF only format.

------------------------------------------------------------------ID: 2487 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.1, Page 202

Electronic submission

Recommendation:

Will evaluators be using Adobe Acrobat reader version 3 to view the proposal?

Rationale:

We would like to understand more about the evaluators' needs, and structure our electronic proposal to make evaluation as easy as possible.

Response:

Adobe Reader 3.0 and the Microsoft Office Pro for Windows 95 application suite will be used to view the proposals.

------------------------------------------------------------------ID: 2488 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.1, Page 202

Electronic submission

Recommendation:

What size monitor will evaluators use to view the proposal? Will on-line evaluation be at 100% view, or can the image be enlarged to 150%?

Rationale:

We would like to understand more about the evaluators' needs, and structure our electronic proposal to make evaluation as easy as possible.

Response:

The proposals will be viewed using 21" monitors and on 12.1" laptops. Adobe Reader 3.0 and the Microsoft Office Pro for Windows 95 suite of applications allow the user to adjust the viewing size of files.

------------------------------------------------------------------ID: 2489 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.1, Page 202

Electronic submission

Recommendation:

Please provide the location where contractors will be allowed to test electronic submissions.

Rationale:

Response:

The offerors are encouraged to send in a sample copy of their electronic proposal, whether it be on disks or CD ROM, to the IPO address specified in Section A, Item 9. The government will test the sample files and provide feedback on the proper structure, hyperlinks, readability, etc of the files.

------------------------------------------------------------------ID: 2490 Date Recvd: 3/17/97 Status: Closed

Reference:

RFP Section L - V2 Section 2.3.1, Page 202

Electronic submission

Recommendation:

Is it possible to speak with someone at the IPO concerning the structure of the electronic proposal?

Rationale:

We have a number of questions concerning how evaluators expect to view the proposals and how we can conform to their needs.

Response:

The electronic evaluation requirements are specified in Section L. The offeror should follow the instructions and submit written clarifications if required.

------------------------------------------------------------------