The application specifically relates to a passive
synthetic aperture sonar direction finding method based on variational
message passing, and belongs to the technical field of
signal processing. The application adopts a broken
line model to fit a distorted array shape, and establishes an array receiving
data model containing array shape disturbance, in view of the problems that a traditional
algorithm can only process space-time coherent signals, is sensitive to array shape
distortion, and has high operation complexity; a
spatial domain super-complete dictionary is constructed to convert a direction finding problem into a sparse
reconstruction problem, a layered
probability model is established by using a
Gaussian scale
mixed model and is expressed as a
factor graph; each parameter
posterior probability is solved by using variational
message passing iteration, high-dimensional matrix inversion is avoided, and angle fine
estimation is realized by combining Laplace interpolation. The application can jointly estimate a
signal source direction and array shape
distortion parameters, keeps high precision in a random
signal and distorted array shape environment, significantly reduces operation complexity, and is suitable for
underwater passive synthetic aperture high-resolution direction finding
engineering application.