TECHNOLOGY AREA(S): Battlespace, Electronics, Sensors

ACQUISITION PROGRAM: PEO IWS 5/PMS 401, Submarine Acoustic Systems Program Office

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 hydrophone (Acoustic Channel Assembly (ACA)) with embedded electronics that comply with the Open Architecture Telemetry (OAT) standard to support receive arrays with increased numbers of hydrophones and telemetry channels per unit length and reduced ACA cost.

DESCRIPTION: Currently, the acoustic channels in towed arrays deployed from surface ships and submarines consist of an acoustic section (hydrophones) and separate telemetry connected via micro-miniature connectors to exfiltrate acoustic information from the array. There are many Acoustic Channel Assemblies (ACAs) in a typical array [Ref. 1]. Innovation is sought to integrate telemetry electronics with acoustic channel assemblies to permit enhanced coherent processing.
Multiple towed array systems, both surface ship, surveillance, and submarine, could utilize the new ACA�s technology and performance. By integrating hydrophones with telemetry electronics as an acoustic channel assembly, towed array designers can achieve higher sensor density with increased coverage overlaps. This will enable processing enhancements of the towed array data.

Present commercial technology and hydrophones focus on single element hydrophone sensors. The designs are typically for stationary sensing and do not incorporate multiple elements or meet the required form factor.

The cost of the present channel assemblies and the associated electronics (telemetry) account for approximately 20 percent of the overall cost of a towed array. The development of an ACA with incorporated telemetry would allow a 5-10% reduction in the overall system cost by eliminating the separate assemblies and the touch labor associated with the wiring and connectors.

The performance of towed arrays improves when there are more ACAs and telemetry channels per unit length [Ref. 2]. Array performance and processing can significantly increase when single paired hydrophone telemetry channels with separate telemetry are replaced with improved acoustic sensors with embedded electronics to support data exfiltration. Integration of hydrophones with key telemetry electronics will provide for inherent redundancy and graceful degradation in the event of a sensor failure.

The Navy needs an innovative technology that combines the acoustic channel performance with an increased number of ACAs and telemetry channels per unit length. This capability will assist the Navy in maintaining or increasing its tactical advantage in the undersea Anti-Submarine Warfare (ASW) domain. The solution will consist of an acoustic sensing section and the associated electronics to acquire the acoustic information, convert signals to a digital format, and then transmit the data to the second-level telemetry backbone. The entire assembly will be packaged as a single unit. The Navy will provide an Interface Control Document (ICD) that defines the incoming power (estimated 100 milli-watts per ACA), channel performance requirements, and the digital output format, which complies with the Department of Justice Interface Control Document standard [Ref. 3]. The ACA acoustic improvement goal is to measurably improve noise rejection (e.g., improve noise rejection greater than 3 dB) of the turbulent boundary layer noise typical for acoustic sensor towed inside a towed array.

ACAs experience extreme environments; therefore, the system and/or sensors must be capable of functioning without damage or degradation in pressures (depth) up to 1200 psi, temperatures over a range of -28�C to 50�C, and accelerations up to 100 Hz over a range of 0.0 g to 25.0 g. The reliability of the ACA must support a Mean Time Between Failure (MTBF) of at least 7000 hours.

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 be implemented and approved by the Defense Security Service (DSS). 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 DSS 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: Develop a concept for an improved ACA that integrates the hydrophone with telemetry electronics identified in the Description. Demonstrate feasibility through modeling, development, and analysis. The Phase I Option, if exercised, will include the initial system specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Design, develop, produce, and deliver two dozen of the Improved Acoustic Channel Assembly prototypes. (Note: The Government will provide support for packaging the assemblies within a towed array as well as environmental testing as required.) Demonstrate the prototypes at a Government- or performer-provided facility. Provide technical support to the Government to conduct environmental testing at NUWCDIVNPT, Middleton, RI and performance testing at NSWC Acoustic Research Detachment, Bayview, ID.

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: Assist the government in transitioning the technology for Navy use. Conduct experimentation and refinement to qualify the system for use on towed arrays. (Note: The Government will provide the performer access to a Navy ship for validation and performance verification of the final system.) Support installation and removal from an at-sea test platform and assist in data recovery and processing using the system for towed arrays.

This system would prove useful for oceanographic research, oil and gas exploration, congested-area traffic monitoring, and other applications where data from multiple disparate sensors are fused to provide a more holistic awareness of the volume being monitored by said sensors, especially where said sensors are not in fixed locations.

REFERENCES:

1. Lemon, S. G. "Towed-Array History, 1917-2003." IEEE Journal of Oceanic Engineering, Vol. 29, No. 2, April 2004, pp. 365-373.� http://ieeexplore.ieee.org/abstract/document/1315726/

2. Burdic, William S. �Underwater Acoustic System Analysis.� Prentice-Hall, Inc.: New Jersey, 2002. https://www.worldcat.org/title/underwater-acoustic-system-analysis/oclc/70580566

3. �Interface Control Document, The Department of Justice Systems Development Life Cycle Guidance Document, Appendix C-16, January 2003.� https://www.justice.gov/archive/jmd/irm/lifecycle/appendixc16.htm

KEYWORDS: Towed Array; Acoustic Channel Assemblies; Turbulent Boundary Layer; Telemetry; Hydrophone; Embedded Electronics in Towed Arrays