Target Localization in Depth and Range from Passive Sonar

This paper presents an active sonar localization method from a passive array. The main difficulty in the passive exploitation of the sonar pulse received and detected by an array is that the transmitted waveform is unknown. This difficulty may be overcome by considering as reference waveform the signal in the beam with maximal energy. We then compute the cross-correlation between the reference signal and the signals in all other beams and we get a constellation of angle-delay points corresponding to the multiple paths in the channel connecting the source to the receiver. We finally estimate the target position by minimizing the Hausdorff Distance between the observed angle-delay pairs and simulated pairs for a sampling of the source possible positions. This localization method has been tested on the real data collected during the ALMA 2015 campaign(shallow-water configuration) and on simulated data in several deep-water configurations.