Coherent Active Sonar Waveform Analysis Using Pressure/Velocity Phase Comparison for Improved Detection and Classification

Navmar Applied Sciences Corporation was awarded a Phase I SBIR program for the Coherent Active Sonar Waveform Analysis Using Pressure/Velocity Phase Comparison for Improved Detection and Classification (Topic No. N091-010) under Contract No. N68335-09-C-0196, dated 14 April 2009 (based on Proposal N091-010-0513). The acronym CASPARS (Coherent Active Sonar Phase Analysis of Reactive Signals) was adopted for use on this program. The objective of this project was to develop a technique to exploit acoustic intensity to enhance the detection of submarines using particle-velocity information and acoustic pressure data. Scattering analysis included the vertical extent of the reactive intensity area and included a reduced frequency analysis to cover realistic source and target sizes. A processing string was developed for real or simulated data, and will accept individual sensor data or multiplexed DIFAR data. Results indicate there is sufficient vertical extent of the forward-scattered field in which a phase shift is detectable for a single DIFAR. An experiment was described to test the performance of the detection process in an ocean environment. This proposal continues this effort to prepare for and conduct a data acquisition sea test and conduct analysis on the data with recommendations for the development of an appropriate system.