Towed Array Position Estimation System
AREA(S): Battlespace, Electronics, Sensors
PROGRAM: PEO IWS 5, PMS 401: Submarine Acoustic Systems Program Office.
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.
Develop a system for determining the position of the headline of the towed
array relative to some fixed point on the towing platform for incorporation
into future towed arrays.
The Navy uses towed acoustic sensor arrays and hull-mounted acoustic sensors to
detect submerged and surface vessels. Each type of sensor provides unique
capabilities [Ref. 1]. In order to take advantage of capability overlap, it is
critical to know key parameters about both systems, including physical location
of towed acoustic sensors relative to each other. However, the ability to
combine these capabilities is limited because state-of-the-art technology
cannot accurately locate the towed array relative to the hull array.
Co-processing sensors provides two main benefits: increasing gain by increasing
the number of channels and aperture at the design frequency; and allowing for
target ranging and localization (triangulating). The required accuracy is a
function of the design frequency of the array. Two (2) wavelengths are
sufficient accuracy for position measurement for co-processing purposes [Ref.
The Navy seeks an innovative solution to determine the relative positions of
the towed and hull arrays to support coherent processing of the combined
arrays. This capability will assist the Navy in maintaining or increasing its
tactical advantage in the undersea warfare (USW) domain. While the Navy
currently has many capable hull-mounted and towed sensors, there is currently
no means to process the towed and hull sensors coherently with each other in
order to provide increased awareness of the battlespace and overall performance
improvement. The solution sought will provide, in three dimensions, accurate
(relative to the wavelength correlating to the design frequency of the array in
question), near real-time (less than one sample delay relative to the array
sample rate) position data of the towed array headline relative to some fixed
point on the towing platform. The array headline position is the most important
position, but fully locating the entire array would be of additional interest
to the Navy. The desired capability must also permit the desirable capabilities
in currently fielded technologies (such as the capability some multi-line towed
array systems use to report relative positions of each of several towed lines
to each other) [Ref. 3].
The proposed solution must be suitable for packaging within towed arrays (no
more than 5.1” long, 0.75” in diameter) and must not cause elevated signatures
(e.g., acoustic or electro-magnetic) in a manner that makes the towing platform
more detectable. Specifically, the system shall not generate any detectable
signals above ambient conditions at a range of 100 yards. While modeling
solutions may be part of the solution, it is anticipated that sensor-based elements
will be required to achieve sufficient accuracy to attain the desired coherent
Sensor elements associated with the proposed solution must survive extreme
environments (as described below) during deployment and must maintain their
accuracy within 10% of nominal (inclusive of drift) over the requirements
described below. The sensor element(s) must suffer no degradation over a
fifteen-year span from time of first use while operating at pressures 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 sensor
element(s) will need to support a Mean Time between Failure (MTBF) of at least
7,000 hours. Testing to validate the technology meets these requirements will
be performed at the Naval Undersea Warfare Center in Newport, RI, or at the
contractor’s facility if deemed sufficient by the Government.
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.
Develop a concept for determining the position of the headline of the towed
array relative to a fixed point on the towing platform. Demonstrate that the
concept can feasibly meet all requirements in the Description. Establish
feasibility through modeling 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.
Develop and deliver a prototype system for testing. (Note: The Government will
provide support for packaging the system within the towed array.) Validate the
prototype through testing. Demonstrate that the position of the headline of the
towed array does not negatively affect the detectability of the towing
platform. Perform testing and validation at a Government-provided facility.
It is probable that the work under this effort will be classified under Phase
II (see Description section for details).
DUAL USE APPLICATIONS: Assist the Government in transitioning the technology
for Navy use. Conduct experimentation and refinement to qualify the technology
for use on towed arrays within the Advanced Processing Build process. (Note:
The Government will provide the performer access to a Navy ship where the final
system validation and performance verification will be conducted.) Support
installation and removal from an at-sea test platform and assist in data
recovery and processing. Use the resulting data to verify the measurements and
accuracy of the system.
This technology 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 sensors, especially where sensors
are not in fixed locations.
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/
William S. “Underwater Acoustic System Analysis.” Prentice-Hall, Inc.: New
Jersey, 1991. https://www.worldcat.org/title/underwater-acoustic-system-analysis/oclc/299606993&referer=brief_results
Chandrasekhar, Vijay et al. “Localization in Underwater Sensor Networks —
Survey and Challenges.” 2006 Proceedings of the 1st ACM International Workshop
on Underwater Networks (WUWNet), pp.33-40. https://dl.acm.org/citation.cfm?id=1161047
Towed Array; Sensor Fusion; Position Measurement; Acoustic Detectability;