An adaptive beamforming (ABF) algorithm is described which can be used for active sonar, particularly a sonar which uses wideband source waveforms such as frequency-modulated (FM) pings, and a bistatic receiver composed of an array of acoustic sensors. The method for obtaining the sensor covariance matrix is critical to this algorithm, and one that works is described and justified. Results using real data with echoes from an undersea target are presented.
James M. Alsup,
"Adaptive beam forming for active sonar", Proc. SPIE 2027, Advanced Signal Processing Algorithms, Architectures, and Implementations IV, (1 November 1993); doi: 10.1117/12.160464; https://doi.org/10.1117/12.160464