Accession Number : AD1011416


Title :   APL - North Pacific Acoustic Laboratory


Descriptive Note : Technical Report


Corporate Author : Applied Physics Laboratory, University of Washington Seattle United States


Personal Author(s) : Mercer,James A ; Andrew,Rex


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1011416.pdf


Report Date : 04 Mar 2015


Pagination or Media Count : 104


Abstract : The ultimate limitations to the performance of long-range sonar are due to ocean sound speed perturbations and the characteristics of the ambient acoustic noise field. Scattering and diffraction resulting from internal waves and other ocean processes limit the temporal and spatial coherence of the received signal, while the ambient noise field is in direct competition with the received signal. Research conducted in the North Pacific Acoustic Laboratory (NPAL) program at the Applied Physics Laboratory (APL-UW) is directed toward a complete understanding of the basic physics of low-frequency, long-range, broadband acoustic propagation, the effects of ocean variability on signal coherence, and the fundamental limits to signal processing at long-range that are imposed by ocean processes. The long-term goal of NPAL is to optimize advanced signal processing techniques, including matched-field processing and adaptive array processing methods, based upon knowledge about the multi-dimensional character of the propagation and noise fields and their impact on long-range ocean acoustic signal transmissions.


Descriptors :   North Pacific Ocean , Underwater acoustics , laboratories , acoustic signals , acoustic tracking , ambient noise , deep water , acoustic measurement , acoustic propagation


Distribution Statement : APPROVED FOR PUBLIC RELEASE