Multibaseline phase unwrapping through robust Chinese remainder theorem

Multibaseline phase unwrapping (PU) is a critical processing procedure of multibaseline synthetic aperture radar interferometry (InSAR). The presence of phase noise makes Chinese remainder theorem (CRT) method not robust enough and inapplicable in practical cases. In this letter, a method based on a robust Chinese remainder theorem (RCRT) is presented to improve the noise robustness of the multibaseline PU. Experimental results prove the effectiveness of RCRT method and demonstrate that the RCRT method is more robust to noise than the CRT method.

I. Introduction

Interferometric synthetic aperture radar (InSAR) has been proposed as a technique for the reconstruction of the ground height profile with high spatial resolution and accuracy [1]–[3]. It exploits the fact that the DEM is related to the SAR interferometric phase. However, the interferometric phase in an InSAR interferogram is measured modulo ., In single-baseline phase unwrapping, it assumes that the (unwrapped) phase jumps between adjacent pixels are less than . This assumption implies the absence of strong discontinuities and high slopes in the ground elevation profile. However, this situation often appears in many applications such as the elevation mapping of mountainous areas and of urban areas.