Wide-swath space-borne SAR and range ambiguity

The suppression of range ambiguities in space-borne SAR would permit a much larger swath, without loss of along-track resolution. Two previously suggested techniques for suppressing range ambiguities are investigated: the first relies upon SAR depth-of-focus; the second uses multiple transmit waveforms. We report that both techniques cause a severe integrated sidelobe ratio (ISLR) degradation, even though the range-ambiguity peak may be significantly lower than the mainlobe peak. Finally, we suggest a null-steering technique which forms nulls in the directions of range-ambiguous returns.