Focusing multiple receiver SAS data using extended range doppler algorithm based on series reversion and data fusion

An exact analytic solution for the two-dimensional (2-D) point target spectrum is usually difficult to obtain because of the existence of a double-square-root term in the multiple receiver synthetic aperture sonar (SAS) range equation. Unlike monostatic SAS, multiple receiver SAS data are more challenging to process because the “Stop-and-Hop” isn´t work. This paper discusses multiple receiver synthetic aperture sonar (SAS) processing using the extended Range Doppler Algorithm. One key step is to use an analytic form of the signal 2-D frequency spectrum derived by the method of series reversion, which can fully consider the space variant in azimuth direction. The other key step is to use a method of azimuth spectrum extension to solve the problem of azimuth undersampling and spectrum coupling. Besides, considered the coherence in the different sub-receiver, multiple receiver SAS data is to process based on data fusion. Simulations have shown that the extended RD algorithm can handle data with more complicated multiple receiver SAS than the previous algorithm.