Long Term Mine Reconnaissance System [LMRS]

Operational Requirements Document

for the

Long-term Mine Reconnaissance System (LMRS)


May 2, 1996



Operational Requirements Document

for the

Long-term Mine Reconnaissance System (LMRS)

1. General Description of Operational Capability

U. S. Naval Strategy emphasizes power projection "Forward...from the sea" and operations in the littorals of potential adversaries that are based upon seamless maneuver and coordination of forces. A basic tenet of this operational maneuver "Forward. from the sea" is that Naval and Amphibious operations will be conducted where the enemy's coastal defenses, including sea mines, are the weakest. To this end, Naval forces must possess an organic mine reconnaissance capability to quickly assess and monitor the extent of the sea mine threat, including the location of gaps in or around suspected minefields. Such an organic capability would be used in advance of dedicated mine countermeasure assets (such as minehunting ships and aircraft). An Organic Offboard Mine Reconnaissance Concept of Operations has been promulgated by the Office of the Chief of Naval Operations (N85, N86, and N87)1 which concludes that no single system can provide the required mine reconnaissance capability in all tactical situations, against the full scope of mine threats, and within the entire water column. As stipulated in the Mission Need Statement (MNS) for Mine Countermeasures (MCM)2, a clandestine capability is required in tactical situations when the conduct of reconnaissance operations would disclose operational intent and place future naval operations at risk. Development of a clandestine mine reconnaissance is furthermore identified as the "top priority" in the Navy's Mine Warfare Plan. To provide the required clandestine capability, the Mine Reconnaissance Concept of Operations calls for forward-positioned submarines to operate organic offboard mine reconnaissance Unmanned Undersea Vehicle (UUV) systems.

The Long-Term Mine Reconnaissance System (LMRS) will be a UUV system that will be clandestinely launched, operated, and recovered from an SSN. The LMRS Cost and Operational Effectiveness Analysis (COEA) investigated several alternative UUV approaches, and concluded that the most cost-effective approach consists of 2l-inch diameter autonomous vehicles that would be stowed in the submarine's torpedo room and launched and recovered via the submarine's torpedo tubes. Each self-powered, self-propelled UUV will be equipped with mine search, mine classification, and navigation sensors for locating mine-like objects in an area of interest. After launch, a vehicle would autonomously transit to the area of interest and begin mine reconnaissance operations. The mine reconnaissance data will be partially processed aboard the vehicle and will be recorded. The vehicle will, at specified intervals,


1CNO Memo 3900 Ser N852J/5U655273, "Organic Offboard Mine Reconnaissance," of 5 May 1995, UNCLASSIFIED

2MNS Ser. No. M042-85-93, "Mission Need Statement for Mine Countermeasures (MCM) (U)," 1 October 1993, CONFIDENTIAL






have the capability to transmit highlights of the mine reconnaissance information to the SSN (either acoustically and/or via direct or satellite-linked radio frequency RF)) for further processing and dissemination to the Fleet1. After completing its mission plan, the vehicle would transit back to rendezvous with the SSN, would be recovered into the torpedo room, and would then be refurbished and prepared for a follow-on sortie. While one vehicle is being refurbished, another vehicle would be conducting transmit mine reconnaissance operations. By refurbishing and recycling the vehicles in this manner, nearly continuous coverage would be provided, within the total system coverage requirements of the system. The primary recipients of LMRS reconnaissance information will be naval forces (other than the host SSN) and amphibious forces. The LMRS, as a secondary mission, should be supportive of providing self-protection, as needed, for SSN missions which are performed in minable waters.

Six to twelve LMRS systems will be procured to deploy on SSNs as the operational need arises. The LMRS will be "portable" and capable of installation in forward areas, but would normally be installed as part of normal pre-deployment preparations. The system will be developed for use by SSN 688/688I and NSSN submarines, but the LMRS vehicles will, by design, not be precluded for use from other submarine platforms or from surface ships.

2. Threat

The threat to LMRS comes primarily from both obsolescent and highly sophisticated

modern mines. These weapons can be used in everything from anti-submarine warfare (ASW)

minefields to coastal defense and anti-invasion minefields. The primary mine threats which LMRS is required to detect and classify are volume, bottom, and near-bottom mines. LMRS will be designed to detect all types oft ethered mines. There is no requirement for LMRS to detect or classify the cases of tethered near-surface mines, floating mines, or buried mines. Approximately 50 countries have mining capabilities and more than half are producers. Many foreign countries have been trained with Soviet or U.S. mine warfare doctrine and are likely to use some derivative ofthese tactics in future operations. Others with little or no formal training may use unconventional approaches which could complicate mine countermeasure efforts. Details on the various LMRS threats are contained in the Office of Naval Intelligence (ONI) publication "Mine Countermeasures Systems Threat Assessment", ONI TA#015-94. The update for this publication is scheduled for dissemination by mid-1996.

3. Shortcomings of Existing Systems

There is currently no clandestine mine reconnaissance capability within the Fleet. In

response to this deficiency, the Navy's Unmanned Undersea Vehicle Program Plan identifies the development of a single stop-gap and limited-capability solution, the Near-term Mine

Reconnaissance System (NMRS), as a top priority to meet the urgent need on an interim basis, until a longer-term, more robust and more capable system, i.e., the LMRS, can be developed. Specifically, LMRS will improve upon NMRS in the following areas: system










reliability and availability, total system area coverage, area coverage rate, and vehicle sortie reach (from the host SSN).

4. Capabilities Required

a. System Performance2

Parameter Threshold Objective

*Vehicle Sortie Reach3 (nm) 75 120

*Total System Area Coverage4 (nm2) 400 650

*Area Coverage Rate5 (nm2/day) 35 50

*Minimum Mine Reconnaissance Water Depth6 (R) 40 40

Maximum Vehicle Operating Depth7 (A) 1000 1500

Nominal Single Vehicle Endurance8 (hr) 40 62

*Mine Positioning Accuracy9 (yds) 100 78

* = Key performance parameter

b. SSN Interface

LMRS operations should not compromise the inherent stealth of its host submarine. The LMRS system will be, as far as technically possible, a carry-aboard system; all SSN modifications necessary to accommodate LMRS will be permanent. The UUV will be required to operate at shallow depths periodically for the purpose ofnavigation updates and RF communications with the submarine. Periscope depth operations by the SSN will be required to communicate reconnaissance data to the Fleet. The frequency and duration ofthese shallow operations should be minimized for both the UUV and the SSN. Speed, heading, and depth constraints on the host SSN may exist during vehicle launch and recovery operations, but otherwise the SSN will be free to operate at any depth within assigned waters.

LMRS UUVs will be launched and recovered through standard SSN 688/688I and NSSN torpedo tubes. The UUV will be analogous to any other weapon in that it would be transferred from its stowed position and loaded into the torpedo tube (along with ancillary hardware that may be needed for launch and recovery) only when it is needed to conduct its mission. LMRS loading, stowage, and handling will be compatible with the SSN's existing weapons loading and handling system. The number of weapons displaced to accommodate LMRS will be kept to a minimum, and as a goal, will not exceed ten weapons. When LMRS is in operation, the torpedo tube(s) being used may be dedicated to the mine reconnaissance operation and may not be available for immediate weapons use. However, once the operation is complete, the tube(s) must be quickly reconfigurable for weapons use; no permanent torpedo tube modifications that would prevent weapons launch will be allowable for LMRS. Replacement of vehicle sections, including energy sections, may be conducted in the









torpedo room. There is no requirement for LMRS to interface with the SSN's fire control system.

The launch and recovery (L&R) process must be capable ofallowing multiple UUV

sorties to be conducted. In other words, the system must be capable of allowing the UUV to be launched, operated, recovered, removed from the torpedo tube, reconfigured, and then reloaded and relaunched for an additional sortie. Should an emergency situation require that the muzzle door be closed while the UUV is deployed, the system will quickly jettison any external connections and appendages that would prevent the muzzle door from closing. The UUV and other ancillary equipment inside the torpedo tube must also be quickly jettisonable in emergency conditions (including UUV jamming inside of the tube) such that the tube can be properly reconfigured for weapon (or another UUV) launch. The UUV will have the capability to scuttle under emergency conditions. The scuttle function will consist of actions to render the UUV software and memory unrecoverable and to flood the UUV, causing it to sink rapidly. The system will be designed to operate only a single UUV at a time during mine reconnaissance operations; however, the simultaneous use of multiple UUVs will not be precluded by design, recognizing that this would require tactical adjustments in the concept of operations and may require additional manning for timely vehicle refurbishment and recycling. Additionally, to expedite supporting continuous operations, a second UUV may be loaded in another torpedo tube and be ready to launch as soon as the first one is fully recovered. Alternatively, a second torpedo tube could be used to house launch & recovery equipment. LMRS will impact a maximum of two torpedo tubes at any given time.

Nominal launch and recovery of the vehicles will be performed with the submarine at

depths between 120 feet (maximum of sea state 2) and the maximum vehicle operating depth. However, vehicle launch and recovery with the submarine at periscope depth is desired. The goal for submarine speed during the L&R evolutions is 3 knots (through the water). However, L&R evolutions (except for at periscope depth) may require near-zero speed (through the water) for a limited period. Neither the launch nor recovery evolution shall take longer than 30 minutes. These evolutions are defined as commencing with the transfer of the UUV from inside a flooded tube until it is outboard or vice-versa.

c. Logistics and Readiness

Parameter Threshold Objective

*System Sortie Reliability10 0.93 0.96

*System Sortie Launch Availability11 0.86 0.92

System Performance Monitoring (PM)12 95% 97%

System Fault Localization (FL)13:

Hardware: 95% to 3 LRU 95% to 1 LRU

Software: 95% to CSU 95% to CSU

* Key Performance Parameter

LRU = Lowest Replaceble Unit

CSU' Computer Software Unit



d. Critical System Characteristics

LMRS will be capable of world-wide use in all submarine operating areas and will be

designed to allow for some amount of environment-induced sensor degradation without impact on mission capability. There will be no mutual acoustic interference between LMRS and own-ship's sonars, apart from presenting itself as a contact to the submarine's acoustic receivers. LMRS will comply with the Guidance Manual for Temporary Submarine Alterations. The LMRS UUVs are not required to withstand the shock of mine detonation, however, the UUV signature (acoustic, pressure, magnetic, or electric) shall be such that the UUV will not detonate a mine at a closest point-of-approach range of 20 yards. LMRS will be designed to be compatible with shipboard environmental requirements such as noise, temperature, electromagnetic interference, and humidity.

5. Integrated Logistics Support (ILS)

a. Maintenance Planning. LMRS will incorporate preventive and corrective maintenance at

the appropriate levels (organizational, intermediate, depot) based upon logistics support and

repair analyses. It will be maintained by ship's force personnel and shore-based maintenance

activities in accordance with a Reliability Centered Maintenance Plan structured for minimal

Level maintenance.

b. Manning. LMRS will be operated by a dedicated cadre supplemented by trained ship's

force. The size of the cadre will be kept to a minimum, and, as a goal, will not exceed 10


c. Support Equipment. LMRS will maximize use of Built-in-Test and Consolidated

Automated Support System in accordance with cost benefit analysis. Requirements for special purpose equipment associated with replenishment and handling, and calibration requirements for special test equipment will be minimized.

d. Human Systems Integration. In an effort to reduce the cost of ownership, a Manpower,

Personnel, and Training (MPT) analysis will be performed in accordance with the guidance of

OPNAVINST 5311.7 (HARDMAN). This analysis will recommend options that maximize the



















cost-effective use of technology to reduce MPT requirements. Tradeoffs which cost-effectively

reduce MPT requirements will be favored during design and development. Final MPT

determination will be documented and validated in a Navy Training Plan in accordance with the guidance of OPNAVINST 1500.8 (series). The system design will analyze human interface

requirements in accordance with ASTM-F1162 (commercial for MIL-STD-1472).

e. Computer Resources. Use MIL-STD-498 to guide computer resource development and

maintenance. Life cycle management must recognize the impact of non-developmental items

NDI) on support.

f. Other Logistics Considerations.

(1) Supply Support. Design will implement Readiness Based Sparing and appropriate

standard supply procedures.

(2) Facilities and Packaging. Handling. Storage & Transportation (PHS&T). The

design will minimize the requirements for unique facilities or special PHS&T.

(3) Technical Data. Technical data for the system must support life cycle maintenance. All technical data shall be acquired or accessed digitally in a manner compatible with defense information infrastructure using accepted national and international standards.

(4) Environmental Protection Planning. In accordance with Part 6 Section I of

DoDINST 5000.2, the program shall incorporate environmental planning, including

pollution prevention, into all aspects of its management strategy for the life cycle.

(5) NDI/COTS. The design and development of the LMRS as well as its logistics

infrastructure should stress the use of NDI and commercial-off-the-shelf (COTS) items, where cost-effective. Furthermore, wherever it is cost-effective to do so, LMRS will utilize components and support infrastructure that is common with UUVs being used for other mission areas. The goal will be to maximize affordability of the system and minimize logistics infrastructure burden at the Fleet level.

6. Infrastructure Support and Inter-operability

The LMRS infrastructure will be established to support 6 month submarine deployments of the system over an operational life of 20 years. The LMRS program will use contractor and fleet support activities as required to ensure life cycle support. The system would normally be installed as part of pre-deployment preparations. The LMRS will require a rapid fly-away capability sufficient to place the ship-deployed equipment in-theater at a forward site for SSN installation. Once in-theater, the system will require forward-site installation and check-out within three (objective) to seven (threshold) days.









The LMRS will be transportable by standard military air, and standard military and/or commercial land and sea modes.

LMRS inter-operability is only required with its host platform, as the system is not intended to interface operationally with other platforms or directly with C4I assets. The LMRS should acquire, process, format, and prepare mine reconnaissance data for transmission to the Fleet in accepted MCM reporting formats". actual transmission of the mine reconnaissance data will be done by the submarine via its standard communications links, . The LMRS is assigned a Joint Potential Designator of Independent.

There are no unique mapping, charting, and geodesy (MC&G), or environmental support requirements for LMRS. LMRS will be supported with standard MC&G products from the Defense Mapping Agency. Digital products and supplemental data from the Navigation Sensor System Interface will be considered as they become available to SSNs.

Meteorological/Oceanographic support will be provided through the Submarine Fleet Mission

Program Library or as standard services and databases produced by Commander, Naval

Meteorology and Oceanography Command (COMNAVMETCOM). Data collected by the LMRS will be made available to COMNAVMETCOM for littoral warfare products.

7. Force Structure

A total of six to twelve LMRS systems will be procured to properly equip the SSN

688/688Is and NSSNs that are expected to operate in forward areas conducting clandestine mine reconnaissance missions. One or more ofthese systems will be used for shore-based training or will be in refurbishment at any given time.

8. Schedule Considerations

Initial Operating Capability (IOC) for LMRS will be achieved when: one LMRS system is deployed, operation and maintenance training completed, and initial shore maintenance training completed. Full Operational Capability (FOC) will be achieved when six LMRS are available for operation, all operation and maintenance training has been completed, maintenance and training facilities have been constructed (if required) and outfitted, and all supporting logistics and technical documentation has been developed.














1. Communication between the UUV and the SSN should be as secure as possible, considering the clandestine nature of the mission. The communication mode (acoustic, direct RF, or satellite-linked RF) actually selected on a given UUV sortie will depend on the tactical situation, the urgency of the communication, the threat, and the capabilities of each mode.

2. System performance is characterized for Total System Area Coverage and Area Coverage Rate for the environmental conditions tabulated below, for bottom and near-bottom targets with target strengths of -20 dB, search sensor probability of detection of 0.85 with a false alarm rate of 1 x 10-5, and probability of classification of 0.95. Threshold performance will be achieved within the full range of environmental conditions specified for each parameter. The minimum/maximum values apply to each parameter in isolation; some level of performance degradation is expected for some combinations of minimum (or maximum) values of individual environmental parameters.

Parameter Minimum Maximum

Temperature (deg C): 0 25

Salinity (ppt): 33 39

Bottom Type (APL/UW index): Coarse silt (15) Cobble, gravel, pebble (3)

Sound velocity (A/s): 4750 5050

Sound velocity gradient: strong negative slightly positive

Sea State: 2 3

Volume Scattering Strength (dB): -60 -80

Furthermore, nominal mine reconnaissance for the measures defined in several endnotes below is characterized at a nominal search speed of 4 knots (through the water) with no current, with reconnaissance operations beginning and ending at a 5 nm range from the SSN. Nominal mine reconnaissance includes search sensor operation 100 percent of the time, and classification sensor operation 15 percent of the time, with the nominal vehicle altitude being 30 feet for search and classification operations.

3. Vehicle Sortie Reach is defined as the distance from the SSN which a UUV can travel

conducting nominal mine reconnaissance along the way, and subsequently return along a parallel path completing the sortie with complete vehicle recovery and a 10% energy reserve.

4. Total System Area Coverage is defined as the summation of the area reconnoitered by six

individual sorties of nominal mine reconnaissance over a single system cycle, not including any reconnaissance coverage overlaps.

5. Area Coverage Rate is defined as the Total System Area Coverage divided by the fractional

number of days (system cycle duration in hours divided by 24 hours) required to complete the

system's mission cycle. The system's mission cycle is defined as the period of time from the

launch (release from the SSN) of the first UUV sortie to the recovery (capture by the SSN) of the last UUV sortie, assuming a total of six consecutive sorties.


6. The minimum depth in which the vehicle is expected to operate and perform nominal mine

reconnaissance. Operation in this water depth is expected in Sea State 2 or less. The sensor field of-view shall extend from the vehicle into shallower water to the maximum extent possible, but is not required to meet the nominal mine reconnaissance requirements in shallower water.

7. The maximum operating depth of the vehicle.

8. Nominal Single Vehicle Endurance is defined as the period of time between separation of the UUV from the SSN and re-capture of the UUV by the SSN at the completion of a sortie, with the UUV performing nominal mine reconnaissance.

9. Mine Positioning Accuracy is defined as the Circular Error Probable (CEP) with a threshold fix reset interval (FRI) of 9 hours and an objective FRI of 12 hours.

10. System Sortie Reliability is the percentage of LMRS nominal sorties, consisting of a complete system cycle of vehicle preparation, launch, nominal mine reconnaissance mission execution, recovery, and post-mission activities, which are successfully completed without a mission critical fault, i.e., without a mission abort. An LMRS nominal sortie is defined to include launch, nominal mine reconnaissance mission execution, and recovery and to have a total endurance of 40 hours.

11. System Sortie Launch Availability is the probability that the system can successfully initiate any UUV sortie (i.e., launch the UUV) when called upon.

12. PM & FL apply to mission critical configuration items.

13. PM & FL apply to mission critical configuration items.

14. Joint Pub 6-04.22, U.S. Message Text Formatting Program - USMTF Message Preparation Instructions (I-O); Message Format C441, Joint Mine Countermeasures Operations [MCMOPS].