A frequency domain differential approach to the absolute phase retrieval in SAR interferometry

A key problem in SAR interferometry is the retrieval of absolute phase values from the interferometric principal phase field provided by pairs of complex SAR images. Because of possible multiple solutions allowed, the unwrapping of fringe patterns is an ill-posed problem. The paper concerns with a different approach to InSAR technique that it is unique in retrieving the height of ground points (except for a constant offset). The basic idea is to repeat raw data focusing by using a range sub-band B_p centered at different frequencies f_p, in order to figure out a point history of the interferometric phase variation vs. frequency. In the paper results will be reported about their current simulations performed with the aim to establish radar parameters (B, f₀, B_p, f_p) that lead to a DEM accuracy less than a fraction of the q_2π