On the Benefit of a Slight PRI Variation for SAR Interferometry

Synthetic aperture radar interferometry is a well-established technique for producing high-resolution digital elevation models of the Earth’s surface. Observations of some interferograms, however, show that coherent azimuth ambiguities may determine phase biases and coherence losses that significantly degrade the interferometric performance. Whereas imposing very low ambiguity levels may represent a severe design constraint, a slight variation of the pulse repetition interval may suffice decorrelating ambiguities and thus reducing the phase biases and coherence losses without affecting the imaged swath width. This work is relevant for the design of future spaceborne interferometric systems and for the enhanced exploitation of current ones.