Real-time continuous active sonar processing

This work describes the development of continuous active sonar (CAS) processing at CMRE. The software uses subband processing to achieve a faster update rate than is possible with pulsed active sonar (PAS). The software development was based on CMRE's PAS processing software, CAINPro, which has been thoroughly tested during previous sea trials and in postprocessing data analysis. Computational efficiency was carefully considered and many optimizations were made so that the software can run in real-time using the constrained computing resources on board CMRE's Ocean Explorer autonomous underwater vehicles (AUV). The software was successfully tested during the REP14 Atlantic sea trial in July 2014, and was able to demonstrate real-time detection of an echo repeater on all nine sub-bands that were processed. The CAS algorithm runs in real-time on the processing board installed on the AUV.