The ambiguities related to Closure-Phase Model Inversion

This paper discusses the ambiguities that arise when trying to invert simple soil moisture models from closure phases in SAR interferometry. It shows that, under reasonable assumptions, the closure phase information is enough to sort acquisitions according to increasing moisture except for a special kind of ambiguity. The reconstructed moisture sequence can be represented on a circle where the most dry and most wet acquisitions lay side by side. The identification of this special pair of acquisitions solves the ambiguity and opens a way to constrained inversions reducing the number of multiple solutions.