Adaptive port-starboard beamforming of triplet arrays

Triplet arrays are single line arrays with three hydrophones on a circular section of the array. The triplet structure provides immediate port-starboard (PS) discrimination. This paper discusses the theoretical and experimental performance of triplet arrays. Results are obtained on detection gain and PS discrimination in several environmental conditions: sea noise, flow noise, coastal reverberation, jammers. New algorithms on adaptive triplet beamforming are applied to data of a sea-trial with a low frequency active sonar. The adaptive beamforming results are compared to other triplet beamforming techniques (optimum gain and cardioid beamforming). It shows that adaptive triplet beamforming outperforms the other beamforming algorithms, either in PS discrimination or in detection. In conclusion, adaptive beamforming appears to be the ultimate solution for triplet beamforming.