Lack of triangularity in SAR interferometric phases

Abstract

If three SAR images are available, it is possible to form three interferograms. In some cases the phases of the three averaged interferograms will not agree among each other and indicate a sort of phase excess or deficit (which we call "lack of triangularity"). In this paper we illustrate theoretically which models can explain such phenomenon and show some real-data examples. The observation of lack of triangularity might be useful to derive informations on the target and also as a warning that the scatterer presents a temporal covariance matrix which is not intrinsically real.