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Multi-Dimensional Ambient Noise Model


TECHNOLOGY AREA(S): Info Systems, Sensors, Battlespace 

OBJECTIVE: Develop and transition key building blocks of a Multi-Dimensional Ambient Noise Model. 

DESCRIPTION: In light of an increasingly competitive undersea operational arena, the Navy is in need of a replacement for the current omni-directional ambient noise model. The envisioned replacement will be a Multi-Dimensional Ambient Noise Model that in full form predicts the vector and statistics of the temporally dependent ambient noise field as a function of location, direction, and season over a broad range of tactical frequencies (10s of Hz to 100s of kHz) and operational environments. The fully formed model will include a comprehensive understanding of sea surface, volume, and bottom noise generation, attenuation and propagation to the underwater sound field (included but not limited to: biologics, acoustic seafloor loss mechanisms, and scattering). Additionally, the model and supporting database will be formed and informed via data assimilation from multiple sources (included but not limited to: Automatic Identification System (AIS) data, marine weather, dedicated passive listening systems, and feeds from tactical Navy sensors). 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 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 ONR 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 framework for a Multi-Dimensional Ambient Noise Model (MDANM). Analyze and specify the sonar or other data requirements necessary to develop and support it. In addition, provide details of the proposed techniques to be used to estimate one or more of the key MDANM parameters to include strategies for how this data can be obtained operationally. Identify architecture, protocols, and formats for MDANM output to the next-generation Submarine Tactical Decision Aid (STDA). Phase I should include plans for a prototype MDANM to be created in Phase II. 

PHASE II: Using operational sonar or other measurement data, refine the methodology and conduct proof-of-concept demonstrations and tests to estimate one or more of the key MDANM parameters and the impact of the increased granularity (in location down to a 5-km scale and direction to 10 degrees) of the predicted noise field on the design and operation of a candidate operational sonar system. Develop partnerships with Program Executive Office Integrated Warfare Systems Undersea Systems (PEO IWS-5) and other stakeholders in development of next-generation tactical decision aid (Advanced Processer Build – 2021 - APB 21). It is probable that the work under this effort will be classified under Phase II (see Description section for details). 

PHASE III: The Phase III effort will require coordination with the Naval Surface Warfare Center, Carderock Division to add the MDANM to the STDA for submarines, and potentially to the Sonar Performance Predictions Functional Segment (SPPFS-STDA) for surface ship configurations and the STDA for Integrated Undersea Surveillance System (IUSS), or STDA-I, for surveillance systems. 


1: Carey, W. M., J. W. Reese, et al. (1997). "Mid·frequency measurements of array signal and noise characteristics." IEEE J. Ocean. Eng. 22(3): 548-565.

2:  Carey, W. M. and R. A. Wagstaff (1986). "Low-frequency noise fields." J. Acoust. Soc. Am. 80(5): 1522-1526.

3:  Cox, H. (1973). "Spatial correlation in arbitrary noise fields with application to ambient sea noise." J. Acoust. Soc. Am. 54(5): 1289- 1301.

KEYWORDS: Noise; Sonar; Submarine; Sensor; Environment; Adaptive 


Robert Headrick 

(703) 696-4135 

Kyle Becker 

(703) 696-6823 

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