Surface clutter suppression for ice sounding radars by coherent combination of repeat-pass data

This paper formulates a new approach for ambiguous surface clutter suppression for ice sounding radars. While surface clutter from the non-orthogonal direction is reduced by means of Doppler and/or SAR processing, the residual surface contributions from across-track may still mask the reflection of internal layers and the bedrock, both coming from the nadir direction. The suggested approach involves several repeated acquisitions separated by certain baselines. It uses a geometry model to derive a synthesized sparse array diagram with adaptive nulls in the direction of the ambiguities. Initial performance evaluations for a P-band space-borne mission indicates that clutter can be suppressed by 30-40 dB. The approach can potentially be demonstrated with airborne sounder data in case precise navigation and motion compensation is ensured.