Advanced wavenumber domain processing for reconstruction of broad-beam, multiple-receiver synthetic aperture imagery

To boost the mapping rate of synthetic aperture sonars (SASs), systems employing multiple hydrophones are used. Images from these multiple-receiver SAS systems are reconstructed from the recorded data using the same algorithms as in single-receiver SAS. Currently the data-sets are converted (via interpolation) into a single-receiver equivalent before reconstruction using the phase centre approximation. Processing multiple-receiver SAS data with singlereceiver reconstruction methods causes image blurring and degradation. In this paper we propose an improved reconstruction method based on the bistatic sonar model. The new method is a refined wavenumber algorithm that avoids the need for the phase centre approximation. The improvement over current methods is significant for systems with many receivers but is traded off against increased processing. More work on the algorithm may show ways of reducing the processing required.