Abstract: The accuracy of InSAR baseline measurement or estimation is the key factor of digital elevation model (DEM) generation. In this paper, a locally knowledge-based InSAR baseline estimation method is proposed, which estimates the InSAR baseline using the interferogram with the flattened earth removal. Choosing two points with the same height after unwrapping the interferogram, and according to the relationship between the baseline and the target point height without knowing the absolute InSAR phase value or the relative difference of the two points, the method can estimate baseline parameters without knowing ground control points. Its validity is illustrated through computer simulations and the estimation accuracy can be achieved at the level of centimeters.

Key words: synthetic aperture radar, baseline estimation, flattened phase, interferometry