J4 ›› 2012, Vol. 39 ›› Issue (5): 47-53.doi: 10.3969/j.issn.1001-2400.2012.05.009

• Original Articles • Previous Articles     Next Articles

A Hybrid Phase Unwrapping Algorithm Combining Branch-Cut and Surface-Fitting for InSAR

ZHANG Yan;FENG Dazheng;QU Xiaoning   

  1. (National Key Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2011-12-13 Online:2012-10-20 Published:2012-12-13
  • Contact: ZHANG Yan E-mail:zhangyan_candy@hotmail.com

Abstract:

A hybrid phase unwrapping algorithm that combines the branch-cut algorithm and surface-fitting method is proposed to slove the problem of phase wrapping in the Interferometric synthetic aperture radar (InSAR). The algorithm applies different methods in different quality regions to unwrap the phase. It first uses the branch-cut algorithm to unwrap the phases in high quality regions for the benefit of high accuracy, then uses the surface-fitting method to fit the phases in low quality regions and finally, optimizes the coefficients of the surface-fitting function using the gene algorithm to obtain the unwrapped phase. Both simulated and experimental results have shown that the new algorithm can avoid the "isolated island phenomenon" of the branch-cut algorithm and the phase gradient error of the least-mean-square algorithm. The proposed hybrid algorithm is more precise than other methods.

Key words: interferometric synthetic aperture radar, phase unwrapping, branch-cut, surface-fitting, genetic algorithms

CLC Number: 

  • TN 958