Exploiting Ambiguities for Along-Track Baseline Calibration of SIMO SAR Formations

Coherent compact Single-Input-Multiple-Output (SIMO) SAR formations have been studied as an attractive alternative to the standard monostatic SAR systems in terms of resolution and swath size. Significant gain in performance can be achieved given that the along-track (AT) spacing is well calibrated. We propose an innovative solution to the problem of AT position knowledge, using ambiguities of isolated point targets. A theoretical model of the interferometric ambiguity phase is provided, showing the direct relation to the AT baseline. Focusing the ambiguity allows us to increase its intensity, making the algorithm feasible even in the presence of clutter. The achievable accuracy is discussed theoretically and based on simulation.