J4 ›› 2011, Vol. 38 ›› Issue (1): 110-116.doi: 10.3969/j.issn.1001-2400.2011.01.018

• Original Articles • Previous Articles     Next Articles

Coregistration of multiple-pass interferograms of a single-baseline InSAR system based on phase gradients

GUO Jiao;LI Zhenfang;BAO Zheng   

  1. (National Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2010-03-23 Online:2011-02-20 Published:2011-04-08
  • Contact: GUO Jiao E-mail:jiao.g@163.com

Abstract:

It is a practical and feasible way to acquire multibaseline interferometric data by utilizing repeat passes of a single-baseline InSAR system. Due to the high coherence, the single-pass pair of SAR images generated by a single-baseline InSAR can be coregistered using conventional methods. However, there exist extreme difficulties in the coregistration operation for multiple-pass SAR images due to the serious temporal and spatial baseline decorrelation, especially in the case of large effective cross-track baseline lengths. Fortunately, the repeat-pass interferograms obtained by a single-baseline InSAR correspond to the identical terrain, i.e., Digital Elevation Model (DEM). Hence the interferograms contain coherent information, even if the SAR images are decorrelated completely. Based on this point, we propose an innovative strategy to coregister the repeat-pass interferograms instead of the SAR images. Computer simulation results show that the proposed method has the ability to align multiple-pass interferograms of a single-baseline InSAR system accurately.

Key words: synthetic aperture radar interferometry (InSAR), digital elevation model(DEM), multibaseline, multiple-pass, interferogram coregistration