Continuous Active Sonar Signal Processing

Current acoustic localization systems utilize a traditional pulse type sonar approach. A low power alternative, which would be more environmentally friendly toward marine mammals while maintaining required performance, is desired. Continuous wave systems that operate at lower average power could provide a solution to these requirements. Continuous tracking will also be possible, resulting in potentially more accurate localization of the target. Doppler effects can be exploited more completely with continuous active sonar operation. Although continuous wave systems have been used for radar applications, their possible applicability to acoustic localization systems has never been determined. Self-jamming, and blind speeds difficulties must be addressed. High clutter rate continuous tracking must be developed. Signal Systems Corporation's approach is to emphasize the signal processing aspects of continuous active sonar (CAS). This allows us to address, in Phase I, the high-risk elements of self-jamming, blind speed and tracking issues. We will develop waveforms, direct blast cancellation, space-time adaptive, and track-before-detect algorithms for CAS operation. We will extend our existing multistatic simulations to assess the applicability of CAS operation to acoustic localization. We will demonstrate direct blast mitigation techniques in Phase I using air-coupled and underwater data.