Combining spectral estimation and BLU interpolation for the reconstruction of low-oversampled staggered SAR data

Abstract:
The combination of SCan-On-REceive with continuous variation of the pulse repetition interval during transmission (staggered operation) is a viable option for the acquisition of high-resolution-wide-swath SAR data. The data acquired in staggered mode is not uniformly sampled and contain gaps within the synthetic aperture mainly due to the interruption of reception during transmission (i.e, due to blockage). Hence, proper reconstruction strategies must be considered in order to minimize artifacts. Conventionally, large oversampling rates are required to ensure low ambiguity levels, but this is not always feasible due to data-rate constraints. Based on an existing two-step (recovery/re-sample) methodology, this paper proposes an strategy for reconstructing low-oversampled staggered data which improves the reconstruction of point-like targets while ensuring the best performance for distributed scatterers.