Interferometric SAR adaptive filtering method for improved yield and detail

This paper presents a family of multiple scale adaptive filters which automatically adapt their impulse response width to the local data characteristics, optimizing the accuracy, yield, and/or detail of interferometric measurements. For interferometric SAR, under the best of conditions, significant filtering is required in order to make reliable phase measurements in topographic mapping and other applications. Typically a filter with fixed impulse response width is applied to the complex interferogram. Yet, interferometric SAR data is extremely variable in terms of signal-to-noise ratio (SNR), intrinsic coherence, amount of detail and severity of the relief present in the terrain. The optimum filter width-even the feasible width-can vary from one resolution element to another in areas of high relief or high deformation gradients