Quantifying the Impact of Range and Azimuth Ambiguities on Multichannel SAR and SAS Image Quality

Abstract:
The area-coverage rate of synthetic aperture radar (SAR) and synthetic aperture sonar (SAS) systems is constrained by along-track sampling requirements, which must be met to mitigate azimuth/Doppler ambiguities. This paper discusses new results in computing the impact of ambiguous returns on synthetic aperture image quality through the ambiguityto-signal ratio (ASR). Standard approaches for ASR calculation are extended to include effects from nonuniform sampling and a novel spatial-frequency based approach is proposed. These new contributions are based on results from the theory of sampling stochastic processes. This paper also extends the analysis to the multibeam case for the standard multiple receive channel case as well as the multiple transmit channel case of multiple-input, multiple-output (MIMO) SAR.