High-resolution beamforming by fitting a plane-wave model to acoustic data
R. S. Hebbert, Leha T. Barkakati · The Journal of the Acoustical Society of America · 1986
The problem addressed in this paper is the representation of the acoustic field at an array of hydrophones as a background plus a small number of plane waves. As data, assume that a narrow-band covariance matrix has been observed. The covariance matrix implied by the model (i.e., background plus small number of plane waves) is adjusted to obtain the least-squares fit to the observed covariance matrix. Since the number of plane waves is not known, one plane wave is initially assumed and others added in succession until the error is no longer reduced. Each plane wave is described by two parameters: power and bearing. However, the power may be eliminated formally. The problem remaining is one of multidimensional optimization with bearings as unknowns.