Analyzing the Vector Intensity and Directionality of Beaufort Sea Ambient Noise Levels, 2008-2014, to Test Viability of an Arctic Passive Acoustic Navigation System
Abstract
This work will perform analytical modeling, numerical simulation, and archival dataanalysis on whether components of ambient noise" fields generated by diffuse (e.g. wind-driven)sources can provide information about the direction and potentially the range of coastlines andregions of ice cover. This information in turn could be exploited by a passive acousticnavigation system in arctic ice-free and ice-covered situations. The work will be broken downinto three stages: (1) Analyzing an existing seven-year vector sensor data set to measure thecorrelation between intensity and directionality of arctic ambient noise levels during ice-freeconditions. Preliminary analysis has found that during open-water conditions noise intensity anddirectionality are highly correlated in this s"hipping-free environment. Therefore, in principlepassive acoustic ambient noise data could be used as an ~acoustic compass~ to orie"nt anunderwater sensor in ice-free arctic environments. (2) Repeating the previous analysis usingsituations when the sensor arrays" were partially or fully covered by ice, to determine under whatconditions vector passive acoustic measurements collected under or" near ice can be used toidentify the direction of open-water/ice boundaries. (3) Combining modeling and data analysis todetermine whether vector intensity measurements of diffuse ocean noise can be used todetermine approximate distance from shore during open-w"ater conditions, or approximatedistance to open water under ice-covered conditions, by comparing active intensity levels withtotal" intensity levels as a function of boundary distance. The vector sensor data consists of over35 ~Directional Autonomous Seafloor Ac"oustic Recorders~ (DASARs), divided among five~sites~ over a 280 km swath in the coastal Beaufort Sea between 2007 and 2014. At eac"h siteDASARs were deployed on the ocean floor in triangular grids with a typical separation of 7 km.This long-term regional dataset provides historical perspective to any shallow-watermeasurements obtained from the CANAPE project.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 23, 2018
- Source ID
- N000141812064
Entities
People
- Aaron Thode
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego