An introduction to synthetic aperture sonar

DTI has demonstrated that synthetic aperture sonar (SAS) can provide orders of magnitude improvement in cross-range resolution when compared to conventional sonar beamforming. Like synthetic aperture radar (SAR), SAS processing requires coherence over multiple measurements, but has long been impractical due to the nature of the ocean environment. We have extended SAR processing ideas to accommodate the issues specific to the underwater environment, and have successfully synthesized apertures extending many thousands of wavelengths. We will present an overview of the theory of SAS processing, how it differs from SAR, and will show experimental results from SAS processing of sonar data.