A passive localization system has been developed at the UW-STREAM to locate sound sources underwater using a compact 4-element array. The localization system relies on both the Time Difference of Arrival (TDoA) algorithm to localize using impulsive signals, and a low-complexity implementation of the matched field processing (MFP) algorithm. The geometry of the array is investigated to optimize the localization accuracy, and the performance is also evaluated in presence of noise. The proposed algorithm is implemented in real-time on a System-on-Chip (SoC) which executes the algorithm. The performance of the algorithm has been assessed to locate harbour porpoises in different environments: the system was fixed in different locations at the bottom of the Bay of Fundy for extended periods of time; it has also been tested in controlled conditions at the mouth of the Halifax harbour; more recently, it was installed on trawl doors to detect Hector’s dolphins near fishing gear in New Zealand.
