On the challenges of Incomplet Sampling in SAR imagery

Incomplete Sampling (IS) is often associated with Compressive Sensing (CS), i.e. to a method to acquire directly a compressed description of a scene. In Radar, the main advantage highlighted in the literature is the reduction of the data-flow between the R.F. front-end and the signal processing that would be otherwise intractable. However, thanks to the technological progresses in fast Analog to Digital Conversion (ADC) and subsequent digital processing, the data-flow to handle is no longer a serious issue except in special cases. The true issue is that it is not always possible to sample the radar signal ideally for practical and uncontrollable reasons. This is particularly the case of high-resolution SAR imagery that requires both a broadband at transmission and a long coherent integration time (synthetic aperture). However, strictly speaking the SAR scenes are not compressible from a C.S. point of view.