CROSS TRACK INFRARED SOUNDER (CrIS)
Sensor Requirements Document (SRD)
for
NATIONAL POLAR-ORBITING OPERATIONAL ENVIRONMENTAL SATELLITE SYSTEM (NPOESS) SPACECRAFT AND SENSORS
Prepared by
Associate Directorate for Acquisition
NPOESS Integrated Program Office
17 March 1997
Integrated Program Office
Silver Spring MD 20910
Table of Contents i1 SCOPE 11.1 IDENTIFICATION 11.2 SENSOR OVERVIEW 11.3 DOCUMENT OVERVIEW 11.3.1 Conflicts 21.3.2 Requirement Weighting Factors 21.4 SYSTEM CLASSIFICATIONS N/A 22. APPLICABLE DOCUMENTS 32.1 GOVERNMENT DOCUMENTS 32.2 NONGOVERNMENT DOCUMENTS 42.3 REFERENCE DOCUMENTS 43 SENSOR REQUIREMENTS 73.1 DEFINITION 73.1.1 Sensor Description 73.1.2 Sensor Segments 73.1.2.1 Satellite interface adapter 73.1.2.2 Isolation System 83.1.2.3 Optical Bench 83.1.2.4 Scan Mirror and Motor 83.1.2.5 Scan Mirror Servo Subsystem 83.1.2.6 Interferometer Moving Mirror Assembly 83.1.2.7 Moving Mirror Servo Subsystem 83.1.2.8 Beamsplitter 83.1.2.9 Alignment Monitor Subsystem 83.1.2.10 Alignment Subsystem 93.1.2.11 Aft Optics 93.1.2.12 Cold Optics 93.1.2.13 Detectors & Preamplifiers 93.1.2.14 Visible Metrology & Sampling Electronics 93.1.2.15 Calibration Subsystem 93.1.2.16 Signal Processing 93.1.2.17 Housekeeping 93.1.2.18 Command & Control 103.1.2.19 Spacecraft Communications 103.1.3 Specification Tree. 103.1.4 Top-Level Sensor Functions 103.1.5 Common Sensor Modes 113.1.5.1 OFF MODE 113.1.5.2 OPERATIONAL Mode 113.1.5.3 DIAGNOSTIC Mode 113.1.5.4 SAFE HOLD Mode 113.1.5.5 CrIS Specific Sensor Modes (TBR) 113.1.6 Operational and Organizational Concept 123.1.6.1 Expendable Launch Vehicle Concept N/A 123.1.6.2 Launch Operations Concept 123.1.6.2.1 Pre Launch 123.1.6.2.2 Launch 123.1.6.3 On-orbit Operational Concept 123.1.6.3.1 On-orbit Tests 123.1.6.3.2 On-orbit Operations 133.2 CrIS CHARACTERISTICS 133.2.1 EDR Performance Characteristics 133.2.1.1 Performance Characteristics 133.2.1.1.1 EDR Requirements 133.2.1.1.1.1 Primary EDRs (CrIS with MW CrIMSS sensors) 133.2.1.1.1.2 Primary EDRs (CrIS with MW CrIMSS and/or other sensors) 173.2.1.1.1.3 Secondary EDRs 173.2.1.1.2 Operational Sensor Data Record (SDR) Requirements 173.2.1.1.2.1 Definition 183.2.1.1.2.2 Content (TBR) 183.2.1.1.3 RDR Requirements (TBR) 193.2.1.1.3.1 Definition 193.2.1.1.3.2 Content 193.2.1.1.4 Algorithms 193.2.1.1.4.1 Convertibility to Operational Code 203.2.1.2 Mission Sensor Calibration (TBS) 203.2.1.3 Data Formatting and Compression 203.2.1.4 Spectral Band 213.2.1.5 Number of Spectral Bands 213.2.1.6 to 3.2.1.17 NA 213.2.1.18 Spectral Range 213.2.1.19 Number of Detectors in the Field of Regard 213.2.1.20 Wavenumbers in a Spectral Band 223.2.1.20.1 Number of wavenumber channels in the Band 223.2.1.20.2 Aliasing 223.2.1.20.3 Wavenumber Step Size 223.2.1.20.4 Unapodized Spectral Resolution 223.2.1.21 Retrieval Spectral Channel Wavenumbers 223.2.1.22 Dynamic Range 223.2.1.23 System Linearity 233.2.1.24 Quantization (TBD) 233.2.1.25 Noise-Equivalent Difference Temperature/ Signal-to-Noise Requirements 233.2.1.25.1 Definition 233.2.1.25.2 Standard Earth Scenes 233.2.1.25.3 Earth Scene Variation 243.2.1.25.4 Noise Performance 263.2.1.26 Absolute Radiometric Accuracy, Precision, and Repeatability 273.2.1.26.1 Absolute Radiometric Accuracy 273.2.1.26.2 Unit Data Set 273.2.1.26.3 Precision 273.2.1.26.4 Short Term Repeatability 273.2.1.26.5 Long Term Repeatability 283.2.1.27 Channel Radiometric Noise Power Spectrum Diagnostic (TBR) 283.2.1.28 CrIS Sensitivity Validation and Calibration 283.2.1.28.1 Ambient Bench Tests (TBR) 283.2.1.28.1.1 Calibration Source Requirements 293.2.1.28.1.2 Electronic Noise 293.2.1.28.2 Thermal Vacuum Ground Calibration 293.2.1.28.2.1 Test Targets 293.2.1.28.2.2 Calibration Source Temperatures 293.2.1.28.2.3 Axial Temperature Gradients 293.2.1.28.2.4 Surface Temperature Gradients 303.2.1.28.2.5 Temperature Variability 303.2.1.28.2.6 Emissivity 303.2.1.28.3 On-orbit Calibration 303.2.1.28.4 Onboard Calibration Frequency 303.2.1.28.5 Onboard Target Emissivity 313.2.1.28.6 Onboard Target Temperature 313.2.1.28.7 Axial Temperature Gradients 313.2.1.28.8 Surface Temperature Variation 313.2.1.28.9 Temperature Stability 313.2.1.29 Scan Requirements 313.2.1.29.1 Type of Scan 313.2.1.29.2 Instantaneous Field of Regard 313.2.1.29.3 In-Scan IFOR Sampling Interval 313.2.1.29.4 Swath Width 313.2.1.29.5 Swath Width Repeatability 323.2.1.29.6 Scan Time 323.2.1.29.7 Scan-to-Scan Separation 323.2.1.29.8 Number and Types of Scan Modes 323.2.1.29.9 Scan Position Knowledge 323.2.1.30 CrIS Spatial Resolution and Sampling 323.2.1.30.1 Detector Geometric FOV 323.2.1.30.2 Geometric Ground Footprint 323.2.1.30.3 NA 323.2.1.30.4 FOV Modulation Transfer Function (MTF) 323.2.1.30.5 FOV Alignment 333.2.1.30.6 FOV Co-registration 333.2.1.31 Polarization NA 333.2.1.32 to 3.2.1.35 NA 333.2.1.36 Stray Light Rejection TBD 333.2.1.37 Earth Location Requirements (TBR) 333.2.1.37.1 Allocations (TBS) 333.2.1.37.2 Sensor Reference Axes Alignment 333.2.1.37.3 Orientation of the Reference Axes 333.2.1.37.4 CrIS Line-of-Sight 333.2.1.37.5 CrIS line-of-sight Pointing Knowledge 343.2.1.37.6 CrIS LOS Jitter 343.2.2 Sensor Capability Relationships 343.2.2.1 Reference Timelines 343.2.3 Interface Requirements 343.2.3.1 External Interface Requirements 363.2.3.1.1 METOP Spacecraft Bus External Interface Description (TBS) 363.2.4 Physical and Interface Characteristics 363.2.4.1 Mass Properties 37373.2.4.1.1 Sensor Mass Documentation 373.2.4.1.2 Sensor Mass Variability Documentation 373.2.4.1.3 Center of Mass 373.2.4.1.3.1 Center of Mass Allocation 373.2.4.1.3.2 Center of Mass Measurement and Documentation 373.2.4.1.4 Moments of Inertia 373.2.4.1.4.1 Moments of Inertia Measurement 373.2.4.1.4.2 Moments of Inertia Accuracy 383.2.4.1.4.3 Moments of Inertia Documentation 383.2.4.1.4.4 Moments of Inertia Variation Documentation 383.2.4.2 Dimensions 383.2.4.2.1 Physical Interface 383.2.4.2.1.1 Stowed and Critical Clearances 383.2.4.2.1.2 Mounting Provisions 393.2.4.2.1.3 Alignment 403.2.4.2.1.4 Structural Support 413.2.4.2.1.5 Sensor Structural Dynamics 413.2.4.3 Power 423.2.4.3.1 Sensor Internal Power 423.2.4.3.1.1 Peak Power TBD 423.2.4.3.1.2 Power Cycle TBD 423.2.4.3.1.3 On-orbit Power TBD 423.2.4.3.1.4 Launch Power TBD 423.2.4.3.1.5 End-of-life Power TBD 423.2.4.3.2 Sensor External Power 423.2.4.3.3 Electrical Power Interface Requirements 423.2.4.3.3.1 Electrical Interfaces 423.2.4.3.3.2 Electrical Current 443.2.4.3.3.3 Grounds, Returns, and References 443.2.4.3.3.4 Power Harnesses 453.2.4.3.3.5 Signal Cabling 453.2.4.4 Survivability 463.2.4.5 Endurance (TBR) 463.2.4.6 Protective Coatings and Finishes 463.2.4.7 Thermal 473.2.4.7.1 General 473.2.4.7.2 Thermal Isolation to Spacecraft 473.2.4.7.3 Heat Transfer 473.2.4.7.3.1 Heat Transfer 473.2.4.7.3.2 Radiation 473.2.4.7.4 Temperature Ranges 483.2.4.7.4.1 Spacecraft Temperature Range 483.2.4.7.4.2 Thermal Uncertainty Margins 483.2.4.7.4.3 Sensor Temperature Range 483.2.4.7.5 Temperature Monitoring 483.2.4.7.5.1 Mechanical Mounting Interface Temperature Monitoring 483.2.4.7.5.2 Sensor Temperature Monitoring 483.2.4.7.5.3 Temperature Sensor Locations 493.2.4.7.6 Thermal Control Design 493.2.4.7.6.1 Thermal Control Hardware 493.2.4.7.6.2 Survival Heater Design 493.2.4.7.6.3 Multilayer Insulation 503.2.4.7.6.4 Other Considerations 503.2.4.8 Data and Command Interface 503.2.4.8.1 General Command Electrical 503.2.4.8.1.1 Interface Conductors 503.2.4.8.1.2 Interface Circuitry Isolation 503.2.4.8.1.3 Interface Fault Tolerance 503.2.4.8.1.4 Power Bus 503.2.4.8.2 Command and Telemetry Data Bus Requirements 513.2.4.8.2.1 Bus Functions 513.2.4.8.2.2 Bus Type 513.2.4.8.2.3 Bus Configuration 523.2.4.8.3 General Bus Requirements 523.2.4.8.3.1 Electrical Interface 523.2.4.8.3.2 Data Bus Monitoring 533.2.4.8.4 Sensor Commands and Memory Load 533.2.4.8.4.1 Command Types 533.2.4.8.4.2 Packetization for Commands and Memory Loads 533.2.4.8.4.3 Documentation 533.2.4.8.4.4 Critical Commands 543.2.4.8.4.5 Frame Sync and Time Code Data 543.2.4.8.5 Health and Status Telemetry Data 543.2.4.8.5.1 Telemetry Diagnostic Data 543.2.4.8.6 Low Rate Science Data 543.2.4.8.6.1 Telemetry and Low Rate Data Packetization 543.2.4.8.7 Data Bus Sampling Rate 543.2.4.9 High Rate Bus 553.2.4.9.1 Bus Functions 553.2.4.9.2 High Rate Data Bus Transmission Rate 553.2.4.9.3 Bus Type 553.2.4.9.4 High Rate Data Packetization 553.2.5 Sensor Quality Factors 553.2.5.1 Reliability 553.2.5.1.1 Operational Service Life 553.2.5.1.2 Maintainability 553.2.6 Environmental Conditions 563.2.6.1 Natural Environment Characteristics 563.2.6.1.1 Total Ionizing Dose Environment 563.2.6.1.2 Cosmic Ray and High Energy Proton Environment 573.2.6.1.2.1 Single Events Radiation Environment 573.2.6.1.2.2 Displacement Damage 583.2.6.2 Launch Environment 583.2.6.2.1 Thermal (TBS) 583.2.6.2.1.1 Temperatures 583.2.6.2.1.2 Heat Flux (TBS) 593.2.6.2.1.3 Free Molecular Heating 593.2.6.2.2 Shock (TBS) 603.2.6.2.3 Acceleration Load Factors 603.2.6.2.4 Vibration 603.2.6.2.5 Acoustics 603.2.7 Transportability 623.2.8 Flexibility and Expansion 633.2.8.1 Operational Computer Resource Reserves 633.2.8.1.1 Computer Resource Reserves for Operational Space Elements 633.2.8.1.1.1 Data Processing Processor Reserves 633.2.8.1.1.2 Data Processing Primary Memory Reserves 633.2.8.1.1.3 Data Processing Peripheral Data Storage (Secondary Memory) Reserves 633.2.8.1.1.4 Data Processing Data Transmission Media 643.2.8.1.1.5 Data Processing Software/Firmware 643.3 DESIGN AND CONSTRUCTION 643.3.1 Materials 643.3.1.1 Toxic Products and Formulations 643.3.1.2 Parts Selection 643.3.1.3 Material Selection 653.3.2 Electromagnetic Radiation 653.3.2.1 Electromagnetic Interference (EMI) Filtering of Spacecraft Power 653.3.2.2 Electromagnetic Compatibility 653.3.2.2.1 General 653.3.2.2.2 Baseline Requirements 663.3.2.2.2.1 Sensor Electromagnetic Compatibility 663.3.2.2.2.2 Interface Margins 663.3.2.2.3 External Environment 663.3.2.2.2.3 Spacecraft Charging from All Sources 673.3.2.3.3 Wiring 673.3.2.3.4 Conducted and Radiated Interface Requirements 673.3.2.3.4.1 Radiated Emission RE101 673.3.2.3.4.2 Radiated Emissions RE102 673.3.2.3.4.3 Radiated Susceptibility RS101 673.3.2.3.4.4 Radiated Susceptibility RS103 673.3.3 Nameplates and Product Marking (See 5.2) 683.3.4 Workmanship 683.3.5 Interchangeability 683.3.6 Safety Requirements 683.3.6.1 Design Safety Criteria 683.3.7 Human Engineering 693.3.8 Nuclear Control 693.3.9 Security 693.3.9.1 Communications Security (COMSEC) 693.3.9.2 Computer Security (COMPUSEC) 703.3.10 Government Furnished Property Usage 703.3.11 Computer Resources 703.3.11.1 Operational Computer Resources 703.3.11.1.1 Operational Computational Equipment 703.3.11.1.2 Operational Application Software (TBD) 703.3.11.1.3 Operating Systems Used in Operational Computers 703.3.11.1.3.1 Sensors Flight Software Requirements 703.3.11.1.3.2 Programming Language 703.3.11.1.4 Software Coding Conventions 713.3.11.1.5 Year 2000 Software Requirements 713.3.12 Sensor Design Requirements 713.3.12.1 General Structural Design 713.3.12.2 Strength Requirements 713.3.12.2.1 Yield Load 713.3.12.2.2 Ultimate Load 713.3.12.3 Stiffness Requirements 723.3.12.3.1 Dynamic Properties 723.3.12.3.2 Structural Stiffness 723.3.12.3.3 Component Stiffness 723.3.12.4 Structural Factors of Safety 723.3.12.4.1 Flight Limit Loads 723.3.12.4.2 Pressure Loads (TBR) 733.3.12.5 Design Load Conditions 743.3.12.6 Sensor Fluid Subsystems 743.3.12.6.1 Tubing 743.3.12.6.2 Separable Fittings 743.3.12.7 Moving Mechanical Assemblies 753.3.12.7.1 Actuating Devices (See 3.3.6.1) 753.3.12.7.2 Sensor Disturbance Allocation 753.3.12.7.3 Sensor Mechanisms 753.3.12.7.4 Uncompensated Momentum 753.3.12.7.5 Sensor Disturbance Allocations 753.3.12.7.5.1 Constant and Periodic Disturbance Torque Limits 753.3.12.7.5.2 Torque Profile Documentation 763.3.12.7.5.3 Thrust Direction Definition 763.3.12.8 Magnetics 763.3.12.9 Access 773.3.12.9.1 Access Identification 773.3.12.9.2 General Access 773.3.12.10 Mounting/Handling 773.3.12.10.1 Handling Fixtures 773.3.12.10.2 Mounting Orientation 773.3.12.10.3 Sensor to Spacecraft Integration and Test Mounting 773.3.12.10.4 Non-Flight Equipment 773.3.12.11 Venting 783.3.13 Operational Ground Equipment: General Design Requirements (TBD) 783.3.14 Non-operational Ground Equipment: (TBD) 783.3.15 General Construction Requirements 783.3.15.1 Processes and Controls for Space Equipment 783.3.15.1.1 Assembly Lots 793.3.15.1.2 Contamination (TBR) 793.3.15.1.2.1 Contamination Control Requirements 793.3.15.1.2.2 Facility Environmental Requirements 803.3.15.1.2.3 Sensor Inspection and Cleaning During I&T 803.3.15.1.2.4 Sensor Purge Requirements 803.3.15.1.2.5 Fabrication and Handling 803.3.15.1.2.6 Device Cleanliness 813.3.15.1.2.7 Outgassing Sensor Sources of Contamination 813.3.15.1.2.8 Atomic Oxygen Contamination 813.3.15.1.3 Electrostatic Discharge 823.4 DOCUMENTATION 823.4.1 Specifications 823.4.2 Interface Control Documents 823.4.3 Drawings and Associated List 823.4.4 Software (Including Databases). 823.4.5 Technical Manuals 823.5 LOGISTICS (TBD) 823.5.1 Maintenance Planning (TBD) 823.5.1.1 Sensor Maintenance Concepts (TBD) 833.5.2 Support Equipment (TBD) 833.5.3 Packaging, Handling, Storage, and Transportation (PHS&T) (TBD) 833.5.4 Facilities (TBR) 833.6 PERSONNEL AND TRAINING (TBD) 833.7 SENSOR SUITE COMPONENT CHARACTERISTICS (if required) (TBD) 834. QUALITY ASSURANCE AND TESTING PROVISIONS 844.1 Quality Assurance 844.1.1 SPECIAL TESTS AND EXAMINATIONS 844.1.1.1 Inspections and Tests of the Sensor 844.1.1.1.1 Sensor Parts, Materials, and Process Controls. 844.1.1.1.2 Sensor Records. 844.1.1.1.3 Sensor Manufacturing Screens 854.1.1.1.4 Non-conforming Material 854.1.1.1.5 Sensor Design Verification Tests 854.2 TESTING 854.2.1 Philosophy of Testing 854.2.2 Location of Testing 854.2.3 Physical Models 854.2.3.1 Engineering Development Unit (EDU) 854.2.3.2 Mass Model 864.2.3.3 Spacecraft/Sensor Mechanical Interface Simulator (TBS) 864.2.3.4 Spacecraft/Sensor Electrical Interface Simulator (TBS) 864.2.4 Math Model Requirements 864.2.4.1 Finite Element Model 864.2.4.2 Thermal Math Model 864.2.5 Structural Analyses 874.2.6 Developmental Testing 874.2.7 Acceptance and Protoqualification Testing 874.2.7.1 Random Vibration Testing 884.2.7.1.1 Acceptance Level Random Vibration Testing 884.2.7.1.2 Protoqualification Level Random Vibration Testing 894.2.7.2 Sine Vibration Testing 904.2.7.2.1 Acceptance Level Sine Vibration Testing 914.2.7.2.2 Protoqualification Level Sine Vibration Testing 914.2.7.2.3 Design Strength 914.2.7.3 Acceleration Testing 914.2.7.4 Shock Testing 924.2.7.4.2 Protoqualification Level Sensor Shock Testing 924.2.7.5 Acoustic Testing 934.2.7.5.1 Acceptance Level Acoustic Testing 934.2.7.5.2 Protoqualification Level Acoustic Testing 944.2.7.6 Thermal Testing 944.2.8 EMC/EMI Testing 944.2.9 Current Margin Testing 954.2.10 Deployment Testing 954.2.11 Outgassing 954.2.12 Requalification of Existing Designs. 954.2.13 Lifetime Testing 954.2.14 Pre-launch Validation Tests. 954.2.14.1 Sensor Pre-launch Validation Tests. 964.3 VERIFICATION 964.3.1 Standard Scenes 964.3.2 Verification Methods 964.3.3 Requirements Validation 974.3.4 Data Bases 974.3.5 External/Built-in Testing 984.3.6 Burn-in 985. PREPARATION FOR DELIVERY 985.1 PRESERVATION AND PACKAGING 985.2 MARKINGS 98
LIST OF FIGURES
Figure 3.1.2 Notional CrIS Sensor Diagram 7Figure 3.1.3 Specification Tree 10Figure 3.2.1.19 Field of Regard (Notional Layout for nine detector case) 22Figure 3.2.1.25.3-1 Three earth radiance profiles for the long wavelength band 24Figure 3.2.1.25.3-2 Three earth radiance profiles for the mid wavelength band 25Figure 3.2.1.25.3-3 Three earth radiance profiles for the short wavelength band 25Figure 3.2.1.25.3-4 Nominal estimated earth scene NEDN for point design and maximum allowable NEDN for black body test targets. 26Figure 3.2.3 Partial System Internal Interfaces 35Figure 3.2.4.3.3.1. Spacecraft-Sensor Electrical Interfaces 43Figure 3.2.4.8.2. Data Transfer Interface 51Figure 3.2.4.8.2.3. Command and Data Handling Interface Topology 52Figure 3.2.6.2.1.1 Maximum PLF Inner Temperatures 59Figure 3.2.6.2.3 MLV Quasi-Static Load Factors 60Figure 3.2.6.2.5 MLV Acoustic Levels 61Figure 3.3.12.7.5.1 Allowable Transmitted Torque 76Figure 4.2.7.1.1 Random Vibration - Acceptance Levels 89Figure 4.2.7.1.2 Random Vibration - Protoqualification Levels 90Figure 4.2.7.2.2 Sinusoidal Protoqualification Test Levels 91Figure 4.2.7.4 Shock Spectrum (Q=10) 92
LIST OF TABLES
Table 3.2.1.18 Notional Spectral Resolution 21Table 3.2.1.25.3 Black body temperatures for equivalent in-band scene radiances. 24Table 3.2.1.25.4 Maximum (TBR) allowed NEDN (mW/m2-sr-cm-1)) 26Table 3.2.4.7.3.2 Worse-Case Hot and Cold Environments 48Table 3.2.4.7.6.1. Thermal Control Hardware Responsibility 49Table 3.2.6.1.1 Total Ionizing Dose Environment 56Table 3.2.6.2.5 Maximum Acoustic Levels 62Table 3.3.12.4.1 Structural Design Factors of Safety 72Table 3.3.12.4.2 Factors of Safety for Pressurized Components 73Table 4.2.7.1.1 Random Vibration - Acceptance Test Levels 88Table 4.2.7.1.2 Random Vibration - Protoqualification Levels 90Table 4.2.7.2.2 Sinusoidal Test Levels 91Table 4.2.7.5.1 Acceptance Acoustics Levels 931 SCOPE
This Sensor Requirements Document sets forth the requirements of the Cross-track Infrared Sounder (CrIS) which is part of the National Polar-orbiting Operational Environmental Satellite System ( NPOESS) series of polar-orbiting spacecraft. The CrIS instrument forms a key component of the larger Cross-track Infrared/Microwave Sounding Suite (CrIMSS) and is intended to operate within the context of the CrIMSS architecture.
The CrIS provides crosstrack measurements of scene radiance to permit the calculation of the vertical distribution of temperature and moisture in the Earth's atmosphere. It also provides supporting measurements for a variety of other geophysical parameters as listed in the Integrated Operational Requirements Document (IORD) (Paragraph 3.2.1.1). The CrIS shall consist of a Michelson interferometer infrared sounder covering the spectral range of approximately 3.5 to 16 microns. It will be operated together with a coregistered microwave crosstrack sounder suite of instrument(s). Note: The current notional baseline performance level assumed for this microwave suite specification will be no less than that currently projected for the Advanced Microwave Sounder Unit-A (AMSU-A) and the Advanced Microwave Sounder Unit-B/Microwave Humidity Sounder (AMSU-B/MHS) microwave sounders, as scheduled to fly on the National Oceanic and Atmospheric Administration (NOAA) K-N' series spacecraft.
One CrIS flight unit is intended to be provided to meet an early flight opportunity on the NOAA N' satellite to be available for launch in 2004. The NOAA N' microwave sounding sensor channels will be provided by the AMSUA and MHS instruments. Three additional CrIS flight units are needed for the NPOESS C1, C3 and C5 spacecraft which will be available for launch in 2007, 2009 and 2010. The microwave sensors to be used with the CrIS as part of the larger CrIMSS sounding suite are TBS. The purpose of a possible early flight opportunity on NOAA N' is to meet user requirements in advance of the first NPOESS launch and to provide early improved IR sounder capability. These data are processed and delivered to the users in the form of Raw Data Records (RDRs), Sensor Data Records (SDRs), and Environmental Data Records (EDRs).
This document contains all performance requirements for the sensor suite. This document also defines all sensor-spacecraft interfaces for the sensor suite. The contractor should use the document as the basis of a proposed sensor suite specification. The documentation listed in section 2.0 follows an approach of minimum specs and standards. The contractor may add to or revise the documents listed in section 2.0 in coordination with the government. The term "[TBD]" applied to a missing requirement means that the contractor should determine the missing requirement in coordination with the government. The term "[TBS]" means that the government will supply the missing information in the course of the contract. The term "[TBR]" means that the requirement is subject to review for appropriateness by the contractor or the government. The government may change "[TBR]" requirements in the course of the contract.
Appendix A contains a definition of the terms used throughout the document. Appendix B, NPOESS survivability requirements, is classified and will be made available after contract award. Appendix C is a Sensor Data Record Characteristics section presently (TBR). Appendix D contains the NPOESS EDR requirements. Appendix E contains the RDRs and EDRs required for each Central and Field Terminal (TBR). Appendix F defines the acronyms and abbreviations used throughout the document. Appendix G describes Potential Pre-planned Product Improvements. Appendix H is the Verification Cross Reference Matrix (TBD).
SRDX1.3.1-1
In the event of conflict between the referenced documents and the contents of this specification, the contents of this specification shall be the superseding requirements.
SRDX1.3.1-2
In the event of a conflict involving the external interface requirements, or in the event of any other unresolved conflict, the contracting officer shall determine the order of precedence.
The requirements stated in this specification are not of equal importance or weight. The following three paragraphs define the weighting factors incorporated in this specification.
a. Shall designates the most important weighting level; that is, mandatory. Any deviations from these contractually imposed mandatory requirements require the approval of the contracting officer.
b. Should designates requirements requested by the government and are not mandatory. Unless required by other contract provisions, noncompliance with the should requirements does not require approval of the contracting officer.
d. Will designates the lowest weighting level. These will requirements designate the intent of the government and are often stated as examples of acceptable designs, items and practices. Unless required by other contract provisions, noncompliance with the will requirements does not require approval of the contracting officer and does not require documented technical substantiation.
The following documents of the exact issue shown form a part of this SRD to the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, see Section 1.3.1. Tailoring of documents in this section is (TBR).
SPECIFICATIONS:
Military
DOD-E-83578A General Specification for Explosive Ordnance
May 96 for Space Vehicles,
Mil-A-83577B Moving Mechanical Assemblies for Space Launch
Feb 88 Vehicles
STANDARDS:
Federal
FED-STD-209E Airborne Particulate Cleanliness Classes in Sep 92 Cleanrooms and Clean Zones
Military
MIL-STD-461D Electromagnetic Emission and Susceptibility
Jan 93 Requirements for the Control of Electromagnetic
Interference
MIL-STD-462D Measurement of Electromagnetic Interference
Jan 93 Characteristics
MIL-STD-1540C Test Requirements for Launch, Upper Stage, and
Sep 94 Space Vehicles
MIL-STD-1541A Electromagnetic Compatibility Requirements for
Dec 87 Space Systems
MIL-STD-1553B Digital Time Division Command/Response
Jan 96 Multiplex Data Bus
MIL-STD-1773B Fiber Optics Mechanization of an Aircraft
May 88 Internal Time Division Command/Response
Multiplex Data Bus
Department of Commerce/NOAA: None (TBR)
OTHER PUBLICATIONS:
Regulations
AFM 91-201 Explosive Safety Standards
7 Oct 94
EWR 127-1 Eastern and Western Range Safety Requirements
31 Mar 95
Handbooks: None (TBR)
Bulletins: None (TBR)
Other
GPS ICD 200 REV "NAVSTAR GPS Space Segment/Navigation User
C, 19 January Interface"(U)
1995
GPS ICD 203, REV "NAVSTAR GPS SA/AS Requirements (S)
B 22 Dec 1993
(Contractors requiring copies of specifications, standards, handbooks, drawings, and publications in connection with specified acquisition functions should obtain them from the contracting activity or as directed by the contracting officer.)
The following documents of the exact issue shown form a part of this SRD to the Extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, see Section 1.3.1.
SPECIFICATIONS: None (TBR)
STANDARDS:
CCSDS 203.0-B-1 CCSDS Recommendations for Space Data System
Jan 87 Standards. Telecommand, Part 3: Data
Management Service, Architectural Definition,
Issue 1
CCSDS 701.0-B-2 CCSDS Recommendations for Advanced Orbiting
Dec 87 Systems, Networks and Data Links, Architectural
Specification
National Hazardous Materials Management Program
Aerospace
Standard (NAS)
411
Rev 2, 29 Apr 94
DRAWINGS: None (TBR)
OTHER PUBLICATIONS: None (TBR)
The following documents are for reference only and do not form a part of this specification. They are listed here because various parts of the SRD refer to them.
SPECIFICATIONS:
Military: None (TBR)
STANDARDS:
DOD 5200.28-STD Department of Defense Trusted Computer System
Mar 88 Evaluation Criteria
MIL-STD-129M Marking for Shipment and Storage Notice 1, 15
1 Jun 93 Sep 89
MIL-STD 961D DoD Standard Practice for Defense
Aug 95 Specifications, w/ Notice 1
MIL-STD-498 Software Development and Documentation
5 Dec 94
MIL-STD-882c System Safety Program Requirements
Jan 93
MIL-STD-1246C Military Standard Product Cleanliness Levels
Apr 94 and Contamination Control Program
MIL-STD-1522A Standard General requirements for Safe Design
May 84 and Operation of Pressurized Missile and Space
Systems
MIL-STD-1542B Electromagnetic Compatibility (EMC) and
Nov 91 Grounding Requirements for Space Systems
Facilities
MIL-STD-1543B Reliability Program Requirements for Space and
Oct 88 Launch Vehicles
MIL-STD-1547A Parts and Materials Program for Space and
Dec 92 Launch Vehicles
MIL-STD-1809 (USAF) Space Environments for USAF Space
Feb 91 Vehicles
TM-86-01 Technical Manual Contract Requirements
Department of Commerce
DOC Sep 95 National Telecommunications and Information Edition Administration, Manual of Regulations for Sep 95 Federal Radio Frequency Management
NOAA
S24.801 Preparation of Operations and Maintenance
2 Dec 88 Manuals
S24.806 Software Development, Maintenance, and User
30 Apr 87 Documentation
S24.809 Grounding Standards
Dec 89
NASA
PPL-21 Preferred Parts List, Goddard Space Flight
March 1995 Center (Updated May 1996)
SP-R-0 022A General Specification, Vacuum Stability
(JSC) Requirements of Polymeric Material for
9 Sep 74 Spacecraft Application
NASA Tech Memo Orbital Debris Environments for Spacecraft
100471 Designed to Operate in Low Earth Orbit
SP 8031 NASA Space Vehicle Design Criteria/Structures
1969
OTHER PUBLICATIONS:
Regulations: None (TBR)
Handbooks
DOD-HDBK-263B Electrostatic Discharge Control Handbook for
(date) Protection of Electrical and Electronic Parts,
Assemblies, Equipment
MIL-HDBK-340 Application Guidelines for MIL-STD-1540B
1 Jul 85
DOD-W-83575 Gen Spec for Wiring Harness, Space Vehicle,
Jun 96 Design and Testing
MIL-I-46058 Insulating Compound. Electrical (for Coating
Printed Circuit Assemblies)
1985 Handbook of Geophysics and Space Environments
AFM 15-111 Surface Weather Observations
1 Sep 96
Bulletins
Other
TRD for NPOESS Technical Requirements Document (TRD) for
(current National Polar- Orbiting Operational
version) Environmental Satellite System (NPOESS)
Spacecraft Payloads
IRD for NPOESS Interface Requirements Document (IRD) for
(current National Polar-Orbiting Operational
version) Environmental Satellite System (NPOESS)
Spacecraft
IORD for NPOESS Integrated Operational Requirements Document
28 Mar 96 (IORD) for National Polar Orbiting Operational
Environmental Satellite System (NPOESS)
Spacecraft Payloads
ASTME-595-93 Standard Test method for Total Mass Loss and
(current Collected Volatile Condensable Materials for
version) Outgassing in a Vacuum Environment
Attachment C AMSU-A Instrument Performance and Operation
S-480-80 Revised Specification (for the EOS/METSAT Integrated
Programs); NASA GSFC
December 1994
SYS/AMS/J0105/BAE AMSU-B Instrument System Specification (British
Aerospace)
03 Feb 1993
(Technical society and technical association specifications and standards are generally available from reference libraries. They are also available in technical groups and using federal agencies. Contact the contracting officer regarding any referenced document not readily available from other sources.)
SRDK3.1.1-1
The CrIS shall be a passive infrared Michelson interferometer that measures the radiation data that is to be incorporated with other data to satisfy NPOESS EDR requirements (See Appendix D).
The primary system segments and subsystems of the instrument are illustrated in Figure 3.1.2.
Figure 3.1.2 Notional CrIS Sensor Diagram
SRDK3.1.2.1-1
The interface adapter assembly shall allow the instrument to interface to any of the standardized attachment points on the spacecraft.
SRDK3.1.2.1-1
The adapter assembly shall transfer loads, torques, and displacements in the sensor to allow flexible placement of the sensor on the bus.
SRDK3.1.2.2-1
Some form of mechanical isolation shall be incorporated into the instrument design to reduce vibrational input at the attachment points to the spacecraft to (TBD) levels.
A rigid metering structure holding interferometer subsystem and scan mirror assembly is required to maintain internal sensor pointing knowledge.
SRDK3.1.2.3-1
The optic bench orientation with respect to the satellite bus shall be known to 10% (TBR) of the ground pointing knowledge error.
SRDK3.1.2.4-1
The scan mirror shall scan cross-track to the satellite motion, sun side to space side. The interferometer and the cross-track microwave instruments should synchronize their start of scan at (TBS) intervals.
SRDK3.1.2.5-1
The scan mirror servo subsystem shall control the motion and velocity to the levels required to meet the performance specifications.
SRDK3.1.2.6-1
The interferometer moving mirror assembly shall employ a proven design approach with demonstrated lifetime and robustness.
SRDK3.1.2.7-1
The moving mirror servo subsystem shall move the mirror in a nearly linear fashion meeting specified velocity error specifications (TBR) during the inteferogram measurement.
SRDK3.1.2.8-1
The beamsplitter shall be optimized to meet the instrument requirements. An effort should be made to minimize the environmental impact of using hygroscopic materials.
SRDK3.1.2.9-1
The alignment monitor subsystem shall measure the relative alignment of the two interferometer arm mirrors continuously during interferometer operation.
SRDK3.1.2.10-1
The instrument design shall incorporate a concept for maintaining alignment to the accuracy required to allow EDR threshold values to be met.
Aft reflective optics after the interferometer may be employed to reduce the beam diameter into the cold optics.
SRDK3.1.2.12-1
The aft optics, including a field stop if required, shall be cooled to minimize background radiation on the detector.
SRDK3.1.2.13-1
No less than (TBD) infrared detectors per channel shall be used in the design.
SRDK3.1.2.13-2
Preamplifiers shall be located as close to the detectors as possible to minimize noise pickup.
SRDK3.1.2.14-1
The sampling electronics shall digitize the interferogram.
Calibration black bodies and controllers will operate continuously to calibrate the instrument on every cross track scan as required.
SRDK3.1.2.16-1
The signal processing shall be incorporated (or accomplished) in a manner that assures there is no information loss in the spectral bands. The downlink data stream should include all data required to apply a proper calibration on the ground and housekeeping data required to determine the health and operational state of the instrument as defined in 3.1.2.17. Data compression, either using filtering or decimation of the interferogram or FFTs, is desirable.
SRDK3.1.2.17-1
The housekeeping data stream shall include at a minimum all voltages, critical currents, and temperatures of the optic bench and optical subsystems, including the beamsplitter housing, the cold optics, and the detectors.
SRDK3.1.2.18-1
The command and control subsystem shall control every aspect of the instrument operation, data taking, and communication with the spacecraft as specified in section 3.2.4.8.
SRDK3.1.2.19-1
The instrument shall communicate with the spacecraft over a (TBS) interface.
As shown in the attached Figure 3.1.3, the requirements for this CrIS SRD flow from the NPOESS InterAgency Operational Requirements Document (IORD), the Interface Requirements Document (IRD), and the NPOESS Technical Requirements Document (TRD).
Figure 3.1.3 Specification Tree
SRDK3.1.4-1
The CrIS sensor shall measure emission from the earth and the earth's atmosphere in the infrared, provide calibration for these data, and provide (TBD) data for the NPOESS measurement missions.
The OFF, OPERATIONAL, DIAGNOSTIC, and SAFE HOLD modes are common to all NPOESS mission critical sensors.
SRDK3.1.5.1-1
In the sensor OFF mode, no power shall be supplied to the sensor.
SRDK3.1.5.2-1
In the OPERATIONAL mode the CrIS shall be in its full functional configuration.
SRDK3.1.5.2-2
In this mode earth scene radiance, calibration, and housekeeping data shall be acquired.
SRDK3.1.5.3-1
The sensor DIAGNOSTIC mode shall support housekeeping and software updates.
SRDK3.1.5.3-2
The DIAGNOSTIC mode shall support trouble shooting.
In the SAFE HOLD mode, health and status data are collected and transmitted. Mission and calibration data are not collected.
SRDK3.1.5.4-1
The SAFE HOLD mode is a power conservation mode. The sensor shall accept a command in the event the spacecraft enters an anomalous configuration or orientation as determined by the spacecraft computer. A power subsystem anomaly is such an event.
SRDK3.1.5.4-2
The spacecraft C&DH will issue power conservation re-configuration commands to the sensors via the data bus that will place the sensor in a safe configuration. The return to the OPERATIONAL mode shall require ground intervention.
SRDK3.1.5.4-3
In this mode most components shall be turned off, with survival heaters activated.
SRDK3.1.5.5-1
The CrIS contractor shall recommend to the Government additional CrIS-specific modes. The recommended modes may include System Test Mode, Storage Mode, Transport Mode, Pre-launch Mode, Launch and Ascent Mode, Deployment and Initialization Mode, and Calibration and Validation Mode.
The CrIS sensors will be delivered and integrated onto the specified satellite platforms.
SRDK3.1.6.2.1-1
During integration various CrIS verification tests shall be required.
During launch and injection to the operational orbit, the CrIS subsystems may be powered on or turned off in order to provide protection from the launch and injection environments or to comply with other specified requirements. Spacecraft telemetry to monitor sensor status will be provided during launch and injection. Spacecraft telemetry transmission to ground monitoring stations would be used to the extent practicable during the injection phase. After insertion into its operational orbit and separation from the launch vehicle, appropriate deployments would be initiated by memory command and/or ground command. Early orbit check-out will be conducted at the NPOESS primary SOC in Suitland, MD.
SRDK3.1.6.2.2-2
All CrIS specific requirements for power, telemetry, and (TBD) needed during launch shall be identified by the contractor.
The NPOESS spacecraft will operate in a near circular, sun-synchronous orbit. The nominal orbit for the spacecraft is 833 km altitude, 98.7 (TBS) degree inclination. The orbit will be a "precise" orbit (i.e., altitude maintained to TBS km, nodal crossing times maintained to 10 minutes throughout the mission lifetime ) to minimize orbital drift (precession). NPOESS must be capable of flying at any equatorial node crossing time. However, the nominal configuration is with the satellite orbits equally spaced, with 0530 and 1330 nodal crossing times for the U.S. Government satellites and 2130 for the METOP spacecraft.
The sun Beta angle, , is the angle between the solar vector (i.e. the spacecraft-sun line) and the orbit plane. For instrument thermal design purposes, the range of for the NPOESS missions is ± 90 degrees. The satellite will maintain the sun on the appropriate side of the spacecraft to meet the 'all beta' requirement. Sensor suite design will allow for approximately a 5 degree infringement of sun on the cold space side of the spacecraft in the case of a noon or midnight orbit.
The sensor shall be capable of operating under the above defined orbit and beta angle environment.
SRDK3.1.6.3-2
The sensor shall be capable of operating for 21 days (with an objective of 60 days) without additional commands.
The initial on-orbit period is devoted to a complete spacecraft checkout and to the calibration and performance verifications of the sensor(s), including the CrIS. The spacecraft and sensor performance verification tests may be repeated at appropriate times during the operational phase of the mission.
The on-orbit CrIS sensors continuously perform all required measurements. Real- time data are continuously sent to the spacecraft. The CrIS sensors receive commands from the spacecraft for either execution in real time or for subsequent on-board execution.
EDR requirements are broken into two categories: primary and secondary. Primary EDRs are those EDR attributes for which a sensor contractor has been assigned primary sensor and algorithm development responsibility. The algorithm may or may not require the use of additional data from other than the primary sensor. Secondary EDRs are those EDR attributes for which the sensor may provide data as a secondary input to an EDR algorithm assigned as a primary EDR to another NPOESS sensor contractor.
SRDK3.2.1.1.1-1
The modifications and clarifications of EDR Requirements in this section shall take precedence over any conflicting requirements or statements in Appendix D of this SRD, the TRD, and the IORD.
The contractor shall identify all sources of data required to meet threshold requirements for the primary EDRs, including data from other sensors, ancillary data sources, etc.
SRDK3.2.1.1.1-3
The contractor shall identify any multiple sensor constraints on the relationships between sensors within CrIMSS or between sensors in different sensor suites that are entailed by the contractor's algorithms for the CrIS primary EDRs which require data from multiple sensors. Such constraints might include, for example, relative pointing knowledge, relative pointing accuracy, co-boresighting, synchronization, etc. Based on this information and the corresponding information from other sensor contractors, the government may impose modified or additional requirements on the CrIS and/or other sensor suites. Secondary EDR requirements by one contractor to another shall be defined by no later than 60 days prior to SRR.
This category of primary EDRs is be satisfied by the CrIS, but may be augmented by data from MW CrIMSS sensors.
SRDK3.2.1.1.1.1-1
At a minimum, the threshold requirements for the following primary EDRs shall be satisfied by the CrIS in conjunction with potential CrIMSS sensors.
Atmospheric Vertical Moisture Profile Appendix D Section 40.2.1
Note: Supplemental information concerning conventions/general EDR requirements can be found in Section 40.1 of Appendix D and are to be followed unless found to be in conflict with modifications and clarifications of EDR requirements identified in this section. The specific EDR attribute values identified below over-ride the corresponding EDR attribute values as cited in Section 40.2.1 of Appendix D.
An atmospheric vertical moisture profile is a set of estimates of average mixing ratio in three-dimensional cells centered on specified points along a local vertical. For this EDR, horizontal cell size is specified at nadir only. The mixing ratio of a sample of air is the ratio of the mass of water vapor in the sample to the mass of dry air in the sample. Clear refers to cases in which the average fractional cloudiness in the array of CrIS spots falling within an "AMSU-A like" footprint is up to 50%. The instrument shall be capable of meeting sounding requirements in situations where none of the individual spots are clear. The sounding requirements represent errors in a given layer. There is no requirement that errors in adjacent layers be uncorrelated.
The attribute numbering in the tables below is consistent with Appendix D except for the preface letter which indicates it is under a unique requirement in this SRD. Any difference in these attributes takes precedence over Appendix D values as they reflect an intentional requirements allocation to this sensor.
Units: gm/kg
Para. No. Thresholds Objectives
K40.2.1-1 a. Horizontal Cell Size 15 km @ nadir 2 km @ nadir
K40.2.1-2 b. Horizontal Reporting (TBD) (TBD)
Interval
K40.2.1-3 c. Vertical Cell Size 2 km 2 km
d. Vertical Reporting
Interval
K40.2.1-4 1. surface to 850 mb 20 mb 5 mb
K40.2.1-5 2. 850 mb to 100 mb 50 mb 15 mb
K40.2.1-6 e. Horizontal Coverage Global Global
K40.2.1-7 f. Vertical Coverage Surface to 100 Surface to
mb 100 mb
K40.2.1-8 g. Measurement Range 0 - 30 gm/kg 0 - 30 gm/km
h. Measurement Uncertainy 10 %/ 2 km
(expressed as a percent of layers
average mixing ratio in 2 km
layers)
Clear (< 50% cloudy)
K40.2.1-9 1. surface to 600 mb 15% or 0.2g/kg 10%
(TBR)
K40.2.1-10 2. 600 mb to 300 mb 20% or 0.1g/kg 10%
(TBR)
K40.2.1-11 3. 300 mb to 100 mb 25% or 0.1g/kg 10%
(TBR)
Cloudy
K40.2.1-12 4. surface to 600 mb 20% or 0.2g/kg 10%
(TBR)
K40.2.1-13 5. 600 mb to 300 mb 40% or 0.1g/kg 10%
(TBR)
K40.2.1-14 6. 300 mb to 100 mb 40% or 0.1g/kg 10%
(TBR)
K40.2.1-15 i. Mapping Uncertainty 5 km 1 km
40.2.1-16 j. Maximum Local Average 8 hrs (TBR) 3 hrs
Revisit Time
40.2.1-17 k. Maximum Local Refresh (TBD) (TBD)
K40.2.1-16 j./k. Minimum Ground 2,200 km (TBR) (TBD)
; Swath-width
K40.2.1-17 (833 km, circular, polar-orbit
altitude)
Note: Supplemental information concerning conventions/general EDR requirements can be found in Section 40.1 of Appendix D and are to be followed unless found to be in conflict with modifications and clarifications of EDR requirements identified in this section. The specific EDR attribute values identified below over-ride the corresponding EDR attribute values as cited in Section 40.2.2 of Appendix.
An atmospheric temperature profile is a set of estimates of the average atmospheric temperature in three-dimensional cells centered on specified points along a local vertical. Clear refers to cases in which the average fractional cloudiness in the array of CrIS spots falling within an "AMSU-A like" footprint is up to 50%. The instrument shall be capable of meeting sounding requirements in situations where none of the individual spots are clear. The sounding requirements represent errors in a given layer. There is no requirement that errors in adjacent layers be uncorrelated.
Units: K
Para. No. Thresholds Objectives
a. Horizontal Cell Size
K40.2.2-1 1. Clear, nadir 18.5 km 5 km
K40.2.2-2 2. Clear, worst case 100 km (TBD)
K40.2.2-3 3. Cloudy, nadir 40 km (TBR) 5 km
K40.2.2-4 4. Cloudy, worst case 160 km (TBR) (TBD)
K40.2.2-5 b. Horizontal Reporting (TBD) (TBD)
Interval
c. Vertical Cell Size
Clear (< 50% cloudy)
K40.2.2-6 1. surface to 300 mb 1 km (TBD)
K40.2.2-7 2. 300 mb to 30 mb 3 km (TBD)
K40.2.2-8 3. 30 mb to 1 mb 5 km (TBD)
K40.2.2-9 4. 1 mb to 0.01 mb 5 km (TBR) (TBD)
Cloudy
K40.2.2-10 5. surface to 700 mb 1 km (TBD)
K40.2.2-11 6. 700 mb to 300mb 1 km (TBD)
K40.2.2-12 7. 300 mb to 30 mb 3 km (TBD)
K40.2.2-13 8. 30 mb to 1 mb 5 km (TBD)
K40.2.2-14 9. 1 mb to 0.01 mb 5 km (TBR) (TBD)
d. Vertical Reporting
Interval
K40.2.2-15 1. surface to 850 mb 20 mb 15 mb
K40.2.2-16 2. 850 mb to 300 mb 50 mb 15 mb
K40.2.2-17 3. 300 mb to 100 mb 25 mb 15 mb
K40.2.2-18 4. 100 mb to 10 mb 20 mb 10 mb
K40.2.2-19 5. 10 mb to 1 mb 2 mb 1 mb
K40.2.2-20 6. 1 mb to 0.1 mb 0.2 mb 0.1 mb
K40.2.2-21 7. 0.1 mb to 0.01 mb 0.02 mb (TBR) 0.01 mb (TBR)
K40.2.2-22 e. Horizontal Coverage Global Global
K40.2.2-23 f. Vertical Coverage surface to 0.01 mb Surface to
(TBR) 0.01 mb (TBR)
K40.2.2-24 g. Measurement Range 180 - 335 K (TBR) (TBD)
K40.2.2-25 h. Measurement Uncertainty 0.5 K
Clear (< 50% cloudy)
K40.2.2-26 1. surface to 300 mb 1.0 K/ 1 km layers 0.5K/1km
K40.2.2-27 2. 300 mb to 30 mb 1.0 K/ 3 km layers 0.5K/1km
K40.2.2-28 3. 30 mb to 1 mb 1.5 K/ 5 km layers 0.5K/1km
K40.2.2-29 4. 1 mb to 0.01 mb 3.5 K/ 5 km layers 0.5K/1km
(TBR) (TBR)
Cloudy
K40.2.2-30 5. surface to 700 mb 2.5 K/ 1 km layers 0.5K/1km
K40.2.2-31 6. 700 mb to 300 mb 1.5 K/ 1 km layers 0.5K/1km
K40.2.2-32 7. 300 mb to 30 mb 1.5 K/ 3 km layers 0.5K/1km
K40.2.2-33 8. 30 mb to 1 1.5 K/ 5 km layer 0.5K/1km
mb
K40.2.2-34 9. 1 mb to 0.01 mb 3.5 K/ 5 km layers 0.5K/1km
(TBR) (TBR)
K40.2.2-35 i. Mapping Uncertainty 5 km 1 km
40.2.2-36 j. Maximum Local Average 8 hrs (TBRI) 3 hrs
Revisit Time
40.2.2-37 k. Maximum Local Refresh (TBD) (TBD)
K40.2.2-36 j./k. Minimum Ground 2,200 km (TBR) (TBD)
; Swath-width
K40.2.2-37 (833 km, circular,
polar-orbit altitude)
Pressure (Surface/Profile) Appendix D Section 40.3.5
Note: Supplemental information concerning conventions/general EDR requirements can be found in Section 40.1 of Appendix D and are to be followed unless found to be in conflict with modifications and clarifications of EDR requirements identified in this section. The specific EDR attribute values identified below over-ride the corresponding EDR attribute values as cited in Section 40.3.5 of Appendix D.
A pressure profile is a set of estimates of the atmospheric pressure at specified altitudes above the earth's surface. The requirements below apply under both clear and cloudy conditions. Pressure is assumed to be a derived quantity. The pressure profile is derived from the temperature and moisture profile as well as an external estimate of pressure at some level in the atmosphere.
Units: mb
Para. No. Thresholds Objectives
K40.3.5-1 a. Horizontal Cell Size 55 km (TBR) 5 km
K40.3.5-2 b. Horizontal Reporting (TBD) (TBD)
Interval
K40.3.5-3 c. Vertical Cell Size 1 km 0 km
d. Vertical Reporting
Interval
K40.3.5-4 1. 0 - 2 km 1 km 0.25 km
K40.3.5-5 2. 2 - 5 km 1 km 0.5 km
K40.3.5-6 3. > 5 km 1 km 1 km
K40.3.5-7 e. Horizontal Coverage Global Global
K40.3.5-8 f. Vertical Coverage 0 - 30 km 0 - 30 km
K40.3.5-9 g. Measurement Range 10 - 1050 mb 10 - 1050 mb
h. Measurement Accuracy
K40.3.5-10 1. 0 - 2 km 1% (TBR) (TBD)
K40.3.5-11 2. 2 - 10 km 1% or 10 mb 3 % (TBR)
(TBR)
K40.3.5-12 3. 10 - 30 km 1% or 1 mb 0.5 % (TBR)
(TBR)
K40.3.5-13 i. Measurement Precision 4 mb 2 mb
K40.3.5-14 k. Mapping Uncertainty 7 km 1 km
40.3.5-15 l. Maximum Local Average 12 hrs 1 hr
Revisit Time
40.3.5-16 m. Maximum Local Refresh (TBD) (TBD)
K40.3.5-15 l./m. Minimum Ground 2,200 km (TBR) (TBD)
; Swath-width
K40.3.5-16 (833 km, circular, polar-orbit
altitude)
3.2.1.1.1.2 Primary EDRs (CrIS with MW CrIMSS and/or other sensors)
This category of primary EDRs is to be satisfied by the CrIS, but may be augmented by data from MW CrIMSS sensors and/or other NPOESS sensor suites identified by the contractor. These EDR requirements are (TBD).
Secondary EDRs are EDRS that might require data from the CrIS as an input to other NPOESS sensor suites. These requirements are (TBS).
In processing RDRs into EDRs the IDPS will generate intermediate-level satellite instrument data files, including Sensor Data Records (SDRs). SDRs are needed for retrospective processing, leading to improved methods, and for archival, for long-term sensor evaluation or troubleshooting. SDRs will be delivered to the same user destinations as the associated EDRs, as specified in the EDR/RDR matrix (Appendix E), which lists delivery destinations of RDRs/EDRs. The generation and delivery of operational SDRs will be the responsibility of the Interface Data Processing Segment (IDPS) Total System Performance Responsibility (TSPR) contractor, not the CrIS contractor.
Sensor Data Records (SDRs) are full resolution sensor data that are time referenced, earth located, and calibrated by applying the ancillary information including radiometric and geometric calibration coefficients and georeferencing parameters such as platform ephemeris. These data are processed to sensor units (e.g. radiance). Calibration, ephemeris and any other ancillary data necessary to convert the sensor data back to sensor raw data (counts) are included.
The operational SDR should at a minimum consist of the following information:
The IDPS (TSPR) contractor, not the CrIS contractor, will be responsible for defining the content of operational SDRs.
The CrIS contractor may recommend the content of operational SDRs. The government, at its discretion, may provide this recommendation to the IDPS (TSPR) contractor.
SRDK3.2.1.1.2.2-1
The CrIS contractor shall participate in technical interchange meetings with the IDPS (TSPR) contractor to support the definition of the operational SDRs with respect to both content and format, if so requested by the government.
The CrIS contractor will determine the content of SDRs generated by the contractor for requirements validation purposes.
SRDK3.2.1.1.2.2.1-1
The sensor shall be capable of allowing the EDR earth location requirements of 5 km mapping uncertainty for moisture profile measurements and 5 km for temperature profile measurements.
SRDK3.2.1.1.2.2.1-2
Mapping uncertainty requirements shall be consistent with the error budget allocation for the spacecraft given in Section 3.2.4.2.1.3. Mapping Uncertainty (as defined in Appendix A glossary) is the Root Mean Square (RMS) error (one sigma) in the geolocation of measured or derived data samples expressed in geodetic coordinates based on a large number of repetitions of the measurement and/or derivation under identical conditions. An "error" is defined as the difference between the measured or derived value and the true value of a parameter. Mapping uncertainty is due to the combined effect of all systematic and random errors affecting geolocation.
SRDK3.2.1.1.2.2.1-3
The CrIS shall support the mapping uncertainty requirements of all EDRs to which it contributes
Since RDRs are processed into EDRs, RDRs are considered to have met their requirements when they are of an appropriate format and quality to be adequately processed into their associated EDRs (i.e. the contractor is responsible for insuring that RDR's support EDR quality. The instrument supplier should determine data content for data that is supplied to the satellite. Quality is that which is adequate to produce EDRs at the threshold level as specified in 3.2.1.1.1).
SRDK3.2.1.1.3.1-1
The CrIS contractor shall be responsible for generating operational RDRs.
SRDK3.2.1.1.3.2-1
The operational RDR shall at minimum consist of the following information(TBR):
SRDK3.2.1.1.4-1
The contractor shall adopt or adapt existing algorithms or develop new scientific algorithms for all primary EDRs. (See Section 3.2.1.1.1.) Adopting an algorithm means using an existing algorithm without change. Adapting an algorithm means using an existing algorithm with some modification, such as different values of coefficients, inclusion of higher order corrections, fusion of additional data sources, etc.
SRDK3.2.1.1.4-2
The EDR scientific algorithms shall, when used on CrIS data in conjunction with data from the microwave component of CrIMSS, provide EDRs that satisfy the requirements of Section 3.2.1.1.1.
SRDK3.2.1.1.4-3
The contractor shall also adopt or adapt existing algorithms or develop new scientific algorithms for all intermediate level data products used to generate the primary EDRs, such as SDRs and flags indicating data quality, clear versus cloudy, etc. Since the CrIS contractor is not responsible for the content or format of operational SDRs, the CrIS contractor may select the appropriate intermediate-level data products needed as inputs to his scientific EDR algorithms in satisfying this requirement. The description of operational SDRs in Section 3.2.1.1.2.2 is provided as guidance. Algorithms need not be provided for data products that are generated by other sensor suites and utilized as inputs to the algorithms for CrIS primary EDRs.
SRDK3.2.1.1.4-4
The contractor shall also identify use of any auxiliary data. The government's Operational Algorithm Teams (OATs), may also recommend science algorithms. These teams have contributed to the definition of the instrument requirements of Section 3. The OATs may also provide advisory information on CrIS functional and calibration requirements.
SRDK 3.2.1.1.4-5
The performance of the scientific EDR algorithms delivered by the CrIS contractor shall meet EDR thresholds and shall be no worse than the performance of algorithms utilized for current (TBR) operational data products for these EDRs, if such operational products exist.
SRDK3.2.1.1.4-6
The contractor shall identify and quantify any EDR algorithm performance degradation resulting from the lack of any data base or other ancillary data.
The government considers the SDR and EDR algorithms adopted, adapted, or developed by the CrIS contractor to be scientific, rather than operational, algorithms. The CrIS contractor is not responsible for identifying or developing operational SDR and EDR algorithms for the CrIS. (Any operational algorithms necessary for the generation of RDRs will ultimately be the responsibility of the CrIS contractor, and the operational code implementing these algorithms will be part of the required flight software. This statement applies to the post-downselect phase of the CrIS program.)
SRDK3.2.1.1.4.1.-1
The scientific SDR and EDR algorithms delivered by the CrIS contractor shall be convertible into operational code 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.
SRDK3.2.1.1.4.1.-2
The means by which the contractor shall validate the requirement that scientific algorithms be convertible to operational code subject to the constraint specified in SRDK3.2.1.1.4.1.-1 is (TBR).
SRDK3.2.1.1.4.1.-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 SRDK3.2.1.1.4.1.-1.
SRDK3.2.1.3-1
The data packets generated by the CrIS shall conform to the Consultative Committee for Space Data Systems (CCSDS) packetization per the (TBS) real-time interface specification and the (TBS) stored data interface specification.
SRDK3.2.1.3-2
If data compression techniques are utilized by the CrIS in generating data packets for storage on orbit, the compression shall be lossless.
A spectral band is defined as the radiometric pass band of the scene radiance for a single detector or group of detectors.
SRDK3.2.1.4-1
Multiple spectral bands shall be contained in the entire spectral range of the CrIS.
The number of spectral bands will be the minimum required to meet all sensitivity requirements.
SRDK3.2.1.5-1
There shall be a minimum of (TBD) bands spanning a spectral range defined notionally in paragraph 3.2.1.18.
(TBD). The minimum notional spectral range is defined in Table 3.2.1.18. The spectral resolution in each band should be sufficient to meet the EDR requirements. Note: A TBD visible band is also suggested for cloud clearing purposes.
Table 3.2.1.18 Notional Spectral Resolution
Wavenumber Range Wavelength Range Maximum Unapodized
(cm-1) (microns) OPD Resolution
(cm) (cm-1)
Band 1 635-1095 9.13-15.75 TBD TBD
Band 2 1210-1600 6.25-8.26 TBD TBD
Band 3 2155-2800 3.57-4.64 TBD TBD
3.2.1.19 Number of Detectors in the Field of Regard
The field of regard will have TBD fields-of-view (FOV) spaced as shown notionally in the Figure 3.2.1.19 below. In each band a separate detector is associated with each FOV. There shall be no significant differences in calibrated observations obtained from different detectors.
Figure 3.2.1.19 Field of Regard (Notional Layout for nine detector case)
There is no unique set of wavenumbers for an interferometer. The radiance spectrum obtained from the cosine transform of the sampled interferogram is continuous and well defined at all wavenumbers in the band.
A fast Fourier transform (FFT) of a sampled interferogram provides a set of spectral radiances uniformly spaced by the wavenumber step size across the band.
SRDK3.2.1.20.1-1
The spectral response at any wavenumber in the band shall be obtained by interpolating between these wavenumber values.
SRDK3.2.1.20.2-1
The analog interferogram signal shall be appropriately filtered to minimize noise aliasing after sampling.
SRDK3.2.1.20.2-2
The filter design shall minimize gain and phase variation in the signal bandpass caused by any moving mirror velocity variations. This potential noise should be addressed in the noise performance estimates of section 3.2.1.25.
The wavenumber step size is defined as the reciprocal of the maximum optical path difference from the first to the final sample in the raw interferogram. The wavenumber step size will vary with off axis field angle and each FOV must be calibrated.
SRDK3.2.1.20.3-1
The wavenumber step size shall be accurately determined to 5 parts in 106 for all FOVs.
The unapodized spectral resolution is defined as the reciprocal of the maximum optical path difference, i.e. if the Optical Path Difference (OPD) change is +/-L, the total double-sided maximum OPD change is 2L and the wavenumber step size is 1/(2L).
A (TBR) set of nominal retrieval spectral channel wavenumbers should be provided.
SRDK3.2.1.21-1
Radiance data from all detectors shall be interpolated to this standard set of spectral channel wavenumbers for retrieval studies and other EDR validations.
The dynamic range of the instrument should allow for the required sensitivity over a range of nominal scenes and calibration targets including a space look.
SRDK3.2.1.23-1
The nonlinearity of specific spectral bands across the instruments dynamic range shall be measured and demonstrated to be stable enough to meet all radiometric requirements.
The signal-to-noise (SNR) ratio requirements are defined at the aperture of the system by the noise equivalent difference irradiance (NEDN). The noise equivalent difference temperature (NEDT) at a given wavenumber is defined by dividing the NEDN at that wavenumber by the derivative of the Planck black body irradiance function evaluated at 250 degrees K at the same wavenumber.
The NPOESS IPO will provide up to 5 sounder data sets in each of the categories/areas listed below for use in developing sensor designs, and in verifying sensor and algorithm performance. There are 24 areas in all. For each area except polar, there will be day and night categories as well, making the total 44 areas or categories (TBR) of standard datasets. The government will create an additional set of up to 5 sounder data sets in each area/category which will be used by the government to determine sensor design performance and algorithm performance.
Location
Climate Area Spring Summer Autumn Winter (NW Corner)
Polar X X 70N 103E
Land: Siberia X X 72N 159W
Coast: Point X X 5S 65W
Barrow X X 5N 8E
Tropics X X X 8N 120W
Land: Amazon Basin X X X X 56N 56E
Coast: Cameroon X X X X 48N 126W
Ocean: E. Pacific X X X 41N 118W
Midlatitudes X 45N 30W
Land: W. Urals X 48N 8E
Coast: Olympic 25N 88E
Peninsula
Desert: Great
Basin
Ocean: Azores
Alpine: Swiss Alps
Sub-Tropical:
Bangladesh
Sounder datasets will have a Horizontal Spatial Resolution (HSR) of 7.5 km (TBR) and cover an area equal to 10X10 HSRs (TBR). Datasets will provide radiance values for each band requested by the contractor. The number of sounding bands modeled will not exceed 1500. Contractors with more than 1500 bands in their design must select which 1500 bands they desire as standard sounder datasets. After delivery of the initial set of sounding datasets, contractors may request copies of the executable models and the input datasets and commands used to create the soundings if they wish to generate additional data in other channels. Sensor responsivity will be assumed to be a top-hat (TBR), since alternate sensor response functions can be characterized and calibrated out.
Surface background data will be taken from the appropriate EO/IR image data file. Radiance data will be based on ground truth profiles of temperature, water vapor, and ozone, and will be computed with MODTRAN in the EO/IR for bands of 2 cm-1 or more. For EO/IR channels with less than 2 cm-1 bandwidth, FASCODE will be used to compute radiance. The temperature, water vapor, and ozone profiles will be available for each dataset given to the contractor. Cloud/no-cloud masks, at the smallest HSR, will be provided with each sounder dataset. Sounder dataset files will be supplied as binary data in raster format, with a 32 bit floating point value for each pixel, and with 1 band/channel per file (TBR). Files will be supplied on TAR tapes (TBR).
The noise performance for the instrument will depend on the Earth scene. The following Earth scenes are representative of the extremes in earth radiance. The interferometer noise will depend on the broad band integrated flux. The black body temperatures for equivalent in-band scenes radiances are given in Table 3.2.1.25.3. The radiance levels are plotted in figures 3.2.1.25.3-1 through -4.
Table 3.2.1.25.3 Black body temperatures for equivalent in-band scene radiances.
Hot (K) Nominal (K) Cool (K)
Band 1 635 - 1095 281 264 233
Band 2 1210-1540 273 254 234
Band 3 2155-2450 287 269 233
Figure 3.2.1.25.3-1 Three earth radiance profiles for the long wavelength band
Figure 3.2.1.25.3-2 Three earth radiance profiles for the mid wavelength band
Figure 3.2.1.25.3-3 Three earth radiance profiles for the short wavelength band
Figure 3.2.1.25.3-4 Nominal estimated earth scene NEDN for point design and maximum allowable NEDN for black body test targets.
SRDK3.2.1.25.4-1
The CrIS shall be designed to provide data to meet the EDR requirements. The maximum (TBR) allowed NEDN values are tabulated in Table 3.2.1.25.4. NEDN values should be sufficiently low to ensure EDR requirements are satisfied.
Table 3.2.1.25.4 Maximum (TBR) allowed NEDN (mW/m2-sr-cm-1))
TEST TARGET T=287 K T=233 K
TEMPERATURE
WAVENUMBER RANGE BIN SIZE NEDN NEDN
(cm-1) (cm-1)
650-900 0.625 0.17 (TBR) 0.10 (TBR)
900-1100 0.625 0.25 (TBR) 0.13 (TBR)
1210-1540 1.25 0.06 (TBR) .03 (TBR)
2155-2400 2.50 0.008 0.002 (TBR)
(TBR)
The following items reflect anticipated CrIS sensor on-orbit performance characteristics to be verified prior to flight through ground test(s).
The absolute radiometric accuracy is the estimate of the bound of the unknown bias error of the calibration process root-mean-squared with any random precision or repeatability component in a specific measurement period.
SRDK3.2.1.26.1-1
The manufacturer shall develop a detailed radiometric error analysis of the instrument, calibration sources, and calibration procedures and minimize errors in traceability to absolute National Institute of Standards and Technology (NIST) standards and estimate the bound on such errors.
SRDK3.2.1.26.1-2
The radiometric error analysis shall include:
SRDK3.2.1.26.1-3
The design shall reflect the absolute accuracy goal of less than 1%.
The unit data set is the measured spectral radiances for all channels, for specified background, mission operating conditions, and time period.
SRDK3.2.1.26.2-1
The sample size of the unit data set shall be no less than 512 (TBR) contiguous samples per spectral channel taken from 512 (TBR) successive processed interferograms.
The radiometric precision of a wavenumber channel is the standard deviation of the spectral radiances in the unit data set for that wavenumber channel. The radiometric precision is specified by the NEDN (section 3.2.1.25).
The short term repeatability of a wavenumber channel is defined as the standard deviation of the means of the spectral radiances in the unit data for that wavenumber channel.
SRDK3.2.1.26.5-1
An ambient reference target of 287 K (TBR) shall be used to measure short term stability.
SRDK3.2.1.26.4-2
The unit data sets from which the means are derived shall be taken every minute over a 60 (TBR) minute period.
SRDK3.2.1.26.4-3
The short term repeatability shall be better than 0.2% (TBR).
The long term repeatability of a wavenumber channel is defined as the standard deviation of the means of the spectral radiances in the unit data for that wavenumber channel.
SRDK3.2.1.26.5-1
An ambient reference target of 287 K (TBR) shall be used to measure long term stability.
SRDK3.2.1.26.5-2
The unit data sets from which the means are derived shall be taken at 12 hour (TBR) spacing over more than a 30 day period (TBR).
SRDK3.2.1.26.5-3
The long term repeatability shall be better than 0.5% (TBR) of the spectral radiances in the unit data.
The CrIS sensor will require diagnostic ground tests.
SRDK3.2.1.27-1
The noise power spectrum of each spectral channel for each detector shall be determined to a resolution better than 1/128 Hz (TBR).
SRDK3.2.1.27-2
The required processing shall be done in near real time, independently and in parallel with any test equipment command and data taking functions.
SRDK3.2.1.27-3
The resulting interferogram shall be available for review within 15 minutes (TBR) of the completion of the data taking period.
SRDK3.2.1.27-4
Provisions shall be made to take such spectral measurements at any time by operator intervention.
SRDK3.2.1.27-5
The complete (undecimated) interferogram shall be provided for diagnostic purposes.
SRD K3.2.1.27-6
Up to four wavenumber operator defined channels shall be displayed simultaneously.
The CrIS sensor will require pre-launch (ground) and on-orbit calibration.
SRDK3.2.1.28-1
The on-orbit calibration source(s) shall be the primary calibration source(s).
SRDK3.2.1.28.1-1
The CrIS shall be tested under ambient conditions prior to thermal vacuum testing with the detectors cooled to mission operational levels.
SRDK3.2.1.28.1-2
These tests shall demonstrate full sensor functionality and validate the radiometric sensitivity of the CrIS over a selected range of expected on-orbit environmental conditions and instrument operational states/modes.
SRDK3.2.1.28.1.1-1
Calibration/test targets suitable for producing CrIS ground scenes flux levels on the detectors shall provide for emulation ground scenes from 270 to 330 K.
SRDK3.2.1.28.1.2-1
The noise performance shall be measured with zero photon flux level on the detectors (TBR).
SRDK3.2.1.28.2-1
The ground thermal vacuum calibration shall be a simulation of the on-orbit calibration.
SRDK3.2.1.28.2-2
The ground calibration shall consist of tests that will validate the radiometric accuracy of the CrIS over the range of expected on-orbit environmental conditions and instrument operational states/modes.
SRDK3.2.1.28.2.1-1
The brightness temperature targets shall provide references near the extremes of the expected scene brightness temperature range.
SRDK3.2.1.28.2.1-2
The calibration/test targets shall be equipped with sensors for National Institute of Standards and Technology (NIST) traceable absolute temperature and temperature uniformity measurements.
SRDK3.2.1.28.2.1-3
The absolute surface temperature knowledge shall be ± 0.1 K (TBR).
SRDK3.2.1.28.2.1-4
The uniformity shall be within ± 0.3 K (1 sigma) (TBR) of the target mean in the thermal vacuum environment.
SRDK3.2.1.28.2.2-1
Calibration/test targets suitable for all CrIS ground scenes shall be provided for at least the temperatures of (approximately and in Kelvin): 200, 240 280, 300, and 330. Cold space look targets near 77 K must be provided.
SRDK3.2.1.28.2.3-1
Temperature difference between the temperature controlled section of the target and the surface viewed by the radiometer shall be determined to +/- 0.05 K (TBR) using NIST traceable measurement techniques and standards.
SRDK3.2.1.28.2.4-1
The maximum temperature difference over the surface of the calibration/test standard shall be less than 0.5 K (TBR).
The surface temperature at monitoring points on or in the calibration/test standard must be able to be held to within 0.05 K over the calibration characterization period at any chosen brightness temperatures in paragraph 3.2.1.28.2.2.
SRDK3.2.1.28.2.6-1
Calibration/test targets shall have a demonstrated effective emissivity greater than 0.98 (TBR) at all wavenumbers in the band to minimize narcissus and stray reflected radiation.
SRDK3.2.1.28.2.6-2
The emissivity shall be known to 0.005 over all spectral bands.
SRDK3.2.1.28.3-1
Any external operational calibration techniques shall not affect the normal sensing performance for scene brightness temperatures through the interferometer nor cause sun glint into the sensor, or any other NPOESS sensor.
SRDK3.2.1.28.3-2
Any external calibration system shall have view angles and other properties that are compatible with the NPOESS spacecraft and all other on-board sensors.
SRDK3.2.1.28.3-3
The calibration standards employed for on-orbit calibration of the CrIS shall provide sufficiently accurate radiometric temperature to enable the CrIS to meet radiometric accuracy requirements listed in paragraph 3.2.1.26 over the expected on-orbit environmental operating conditions of the CrIS.
SRDK3.2.1.28.3-4
The CrIS shall incorporate a calibration system that uses a minimum of two signal levels (hot and cold effective scene brightness temperatures).
SRDK3.2.1.28.3-5
The CrIS shall incorporate at least one internal warm target with a temperature range from 290 to 310 K. The cold radiance level may utilize a cold space view.
SRDK3.2.1.28.4-1
The calibration target radiance in all channels shall be measured once per scan as required. A number of calibration samples taken during successive scans may be averaged to improve the calibration target signal-to-noise.
SRDK3.2.1.28.5-1
Calibration/test targets shall have a demonstrated effective emissivity greater than 0.98 (TBR) at all wavenumbers in the band.
SRDK3.2.1.28.6-1
The brightness temperature of the onboard calibration standard(s) shall provide an accurate references in the temperature range 290-310 K.
SRDK3.2.1.28.7-1
Temperature difference between the temperature controlled section of the target and the surface viewed by the radiometer shall be measured to 0.03 K (TBR) by a one-time test ground test using NIST traceable measurement techniques and standards.
SRDK3.2.1.28.8-1
The maximum temperature difference over the surface of the calibration/test standard shall be less than 0.5 K (TBR).
The surface temperature at monitoring points on or in the calibration/test standard must be able to be held to within 0.05 K over the calibration characterization period at any chosen brightness temperatures.
SRDK3.2.1.29.1-1
The CrIS shall be a cross track, scanning sensor, with step-and-stare compensation.
The CrIS Instantaneous Field of Regard (IFOR) is defined as 3.3 by 3.3 degrees (TBR).
SRDK3.2.1.29.3-1
The IFOR sampling interval along the scan shall be 3.3 degrees (TBR).
SRDK3.2.1.29.4-1
The scan extent shall be the minimum required to satisfy EDR requirements in section 3.2.1.1 but no less than +/- 49.5 (TBR) degrees from nadir.
SRDK3.2.1.29.4-1
The scan shall be repeated every 3.3 degrees (TBR).
The cross track scan time is the time required to move the nadir intersection with a ground IFOR width as referenced from nadir.
SRDK3.2.1.29.7-1
The Scan-to-Scan separation shall be the swath width defined in 3.2.1.29.5. as referenced from nadir.
SRDK3.2.1.29.8-1
The CrIS shall have the minimal number of scan modes required to meet the EDR requirements.
SRDK3.2.1.29.9-1
The CrIS shall provide a measurement and readout capability to determine the angular position of the CrIS LOS in the azimuth direction relative to the satellite velocity vector.
SRDK3.2.1.29.9-2
This measurement shall be accurate to (TBD) degrees and consistent with the Earth location and EDR requirements.
The geometric FOV is defined as the angle subtended by the maximum dimension of the geometric ground footprint.
The geometric ground footprint is the geometric projection of the detector field stop onto the earth at nadir.
SRDK3.2.1.30.4-1
The shape of the angular detector FOV shall be determined by an MTF measurement at (TBS) spatial frequencies.
SRDK3.2.1.30.5-1
The location of each FOV footprint relative to the optical boresight shall be known to less than 5% (TBR) of the geometric FOV.
SRDK3.2.1.30.6-1
The centroid of the FOV of all detectors with the same nominal FOV location shall fall in a circle with a diameter equal to 3% (TBR) of the geometric FOV. The goal is for spatial areas of the scenes observed by all detectors with the same nominal FOV location to overlap by at least 97% of the area observed by a given detector.
The alignment relative to the spacecraft, and knowledge of the CrIS Line-of-Sight (LOS) in conjunction with the spacecraft attitude and ephemeris data will allow the Earth location of the CrIS sensor data in geodetic latitude and longitude to be corrected for altitude within the accuracy specified for each EDR in Appendix D.
SRDK3.2.1.37.2-1
The CrIS shall have a well defined vertical reference axis and perpendicular azimuth axis.
SRDK3.2.1.37.2-2
These axes shall be used for alignment of the CrIS LOS and the overall alignment of the CrIS to the NPOESS spacecraft.
SRDK3.2.1.37.3-1
The CrIS shall have external optical alignment references to define the mechanical reference axis and establish the orientation of the mechanical reference axes relative to the spacecraft primary mechanical axes.
SRDK3.2.1.37.4-1
The CrIS line-of-sight (LOS) shall be defined by the location of the center of the Instantaneous Field-of-Regard (TBR).
SRDK3.2.1.37.5-1
The line-of-sight pointing knowledge shall be less than or equal to 0.1 degree (TBR) for all absolute measurements and less than or equal to 0.05 degrees (TBR) for all relative measurements in both in-track and cross track directions. Variations in the elevation plane angle of each FOV, which may be characterized and shown to be repeatable or which are predictable from a knowledge of the scan mirror position, spacecraft attitude, and/or orbital position, are not to be included in this uncertainty budget. These systematic variations are to be predicted as part of the CrIS design, but reach final characterization after launch for removal by data processing techniques.
SRDK3.2.1.37.6-1
The line-of-sight shall be stabilized to 1% (TBR) of the FOV during the interferogram measurement.
(TBD)
The system interfaces relevant to the sensors are depicted in Figure 3.2.3 below. Interface requirements for flight on other platforms (e.g. POES N and N') are (TBS).
Figure 3.2.3 Partial System Internal Interfaces
Weight, power, volume and data rates described herein 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 the 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.
SRDK3.2.4-1
The mass of the CrIS sensor shall be less than or equal to 68 kilograms (TBR)
SRDK3.2.4-2
The dimensions of the CrIS sensor shall be less than or equal to the following limits:
SRDK3.2.4-3
The power consumption of the CrIS sensor shall be less than or equal to 82 Watts (TBR).
SRDK3.2.4-4
The data rate of the CrIS sensor shall be less than or equal to the following limits:
Continued in File CRIS-B.DOC