Simulation Study for Missing Sample Estimation and Resampling in NISAR Perspective

NISAR (NASA-ISRO Synthetic Aperture Radar) is world's first Dual frequency (L-band 1.25 GHz & S-band 3.2 GHz) SweepSAR mission which will be operating in staggered PRI (Pulse Repetition Interval) mode in order to distribute the blind ranges uniformly across swath. Blind ranges result in missing samples in the received SAR echo data which can generate artifacts in the processed image. Thus it calls for estimation of missing samples. This paper presents the methodology for estimation of missing samples using optimum interpolator in non-uniformly sampled data. The interpolator is futher used to resample non-uniformly sampled data to uniform grid. Efficacy of the interpolation process has been demonstrated through simulation.