Data volume reduction in high-resolution wide-swath SAR systems

High-resolution wide-swath (HRWS) synthetic aperture radar (SAR) systems are very attractive for the observation of dynamic processes on the Earth´s surface, but they are also associated with a huge data volume. In order to comply with azimuth ambiguity requirements, in fact, a pulse repetition frequency (PRF) much higher than the required processed Doppler bandwidth (PBW) is often desirable. The data volume can be drastically reduced, if on-board Doppler filtering and decimation are performed prior to downlink. A finite impulse response (FIR) filter with a relatively small number of taps suffices to suppress the additional ambiguous components and recover the original impulse response. This strategy is also applicable and especially relevant to staggered SAR systems, where on-board Doppler filtering and resampling can be jointly implemented.