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Non-acoustic, High Fidelity, Short Range Underwater Tracking System


RT&L FOCUS AREA(S): Autonomy

TECHNOLOGY AREA(S): Ground / Sea Vehicles

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a non-acoustic underwater Mine Countermeasures (MCM) tracking system with accuracies suitable for signature measurements within 1-2 yards.

DESCRIPTION: This SBIR topic seeks technology to reduce the susceptibilities of Explosive Ordnance Disposal (EOD) MCM equipment in a broad range of contested operational environments, specifically high-risk mine areas while improving EOD ability to enable fleet access and maneuver in challenged sea space. The technology will build a more lethal force and improve fleet readiness. Current available systems use various forms of acoustic tracking beacons which interfere with the acoustic data collection, require very accurate placement of additional hydrophones and do not have the centimeter or inch level of accuracy needed for the small items (UUVs, ROV Divers) used by Expeditionary Mine Countermeasures (EXMCM).

Navy Expeditionary forces responding to underwater threat objects require an ability to safely deploy and operate Maritime Expeditionary Mine Countermeasures Unmanned Undersea Vehicle (MEMUUV) systems and Maritime Expeditionary System of Systems Response (MESR) Remotely Operated Vehicles (ROVs) in a broad range of environments. Navy Expeditionary forces thus require stringent signature measurement and control, which can only be achieved with highly accurate tracking. Once high accuracy tracking is implemented, electromagnetic and acoustic signature reduction techniques can be applied at exactly known sources on the EXMCM EOD equipment.

After measuring first generation USN UUV and ROV signatures using arrays of acoustic sensors at multiple field tests, it became clear that the existing acoustic tracking techniques did not have the tracking range-position spatial resolution required to provide the level of signature fidelity necessary to adequately characterize for minefield suitability purposed, EOD systems for the purposes in which they are employed.

Existing systems normally involve the attachment of a known high-frequency, high-power, and narrow bandwidth acoustic transponder on the vessel under test, such that through the detections on multiple sensors located on the range, a determination of range can be accomplished. For fairly large USN vessels that create more noise than smaller units, increased stand-off ranges are possible, and errors or variations in range accuracy are much more tolerable.

A tracking system would help improve the ability to ensure minefield suitability of EXMCM EOD equipment (e.g., UUVs, ROVs, diver-held sensors as well as other equipment operating in mine danger areas [e.g., EOD boats]) and supports USN UUV systems as defined in the Secretary of the Navy Report to Congress on Autonomous Undersea Vehicle Requirements for 2025.

UUV tracking experience for measurements of <10 yards sensor to source highlighted that acoustic tracking technology achieved marginal accuracy, if at all, and required dynamic positional accuracy for close-in high-fidelity tracking. The goal of this SBIR topic is to design a system to provide accurate, real-time tracking capability in both sea water and fresh water locations. The tracking accuracy threshold is plus or minus 7 inches with an objective of plus or minus 3 inches at a 6-foot Closest Point of Approach (CPA) over a dynamic range of plus or minus 60 feet from CPA. This capability would allow signature reduction prioritization in the developmental stages of EOD equipment production as well as lowering the risk of expensive equipment loss when employed in combat. Naval Surface Warfare Center Carderock Division (NSWCCD) will test the prototype tracking at an appropriate site to verify 3” accuracy at 6 feet both static (in a tank [e.g., TRANSDEC]) and dynamically in a tank [e.g., CD tow tank]).

The Phase I effort will not require access to classified information.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. Owned and Operated with no Foreign Influence as defined by DOD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this contract as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advance phases of this contract.

PHASE I: Design a concept for a tracking system that can provide accuracies on the order of inches while tracking an underwater object in real time as detailed in the Description. Demonstrate the feasibility by modeling and simulation as well as technical and engineering design review. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Develop a prototype tracking system and validate it with accuracies suitable for signature measurements within 1-2 yds. NSWCCD will test the prototype in an appropriate tank and document the tracking algorithm and fidelity (improved range accuracy of 3 inches at 6 feet). Demonstrate the system with a full underwater acoustic measurement array. Plan and conduct a requirements analysis session with the Navy technical team to further refine source mounting, feasibility (e.g., determine if anything that’s attached to the unit for tracking affects the performance of the unit, if any additional sensor needed for the system should be added to systems being measured) and UUV interface requirements for a prototype tracking system. Refine the demonstration prototype of an improved tracking system with a designated small or medium-sized Government Furnished Equipment and Information (GFE/GFI) UUV and/or ROV asset.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: Work with the Navy personnel and contractor Field Service Representatives (FSRs) to transition the technology to Navy use and gain additional detail on the designated EOD systems that ultimately would be used for integrating the improved tracking system. Support the Navy testing and evaluation team with introduction of the tracking system as a potential ranging capability for UW EOD systems.

A potential platform for this tracking system is the Underwater Signature Measurement System (USMS), a prototype multi-influence point ranging sensor system developed jointly by the NSWCCD and industry partners, consisting of advanced magnetic, electric, pressure, and acoustic sensors that have been selected and integrated into two qualification units consisting of a cylinder (USMS#1) and a hemisphere (USMS#2). USMS#2 is the proposed unit to be upgraded and made suitable for EOD UUV/ROV vehicle tracking and underwater EM communication.

Additionally, several commercial companies produce UUVs and ROVs for U.S. and allied military applications including mine countermeasures, port protection, underwater unexploded ordnance remediation, and naval oceanographic mapping missions. These missions may benefit from the improvements in off hull tracking.

The tracking system could also be adapted to small and medium-sized UUVs used for underwater tracking and surveillance tasks by the gas and oil industry, fisheries, scientific research communities, commercial diving and salvage industries; and have a wide applicability in high accuracy tracking applications, even outside of signature applications.


  1. Luo, Junhai, Han, Ying and Fan, Liying. “Underwater Acoustic Target Tracking: A Review.” Sensors (Basel), 2 Jan 2018.  
  2. Mabus, Ray. “Report to Congress – Autonomous Undersea Vehicle Requirements for 2025.”
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