Journal of Systems Engineering and Electronics ›› 2014, Vol. 25 ›› Issue (3): 422-427.doi: 10.1109/JSEE.2014.00048

• DEFENCE ELECTRONICS TECHNOLOGY • Previous Articles     Next Articles

Azimuth resolution improvement for spaceborne SAR images with quasi-non-overlapped Doppler bandwidth

Yanyang Liu*, Zhenfang Li, Zhiyong Suo, Jinwei Li, and Zheng Bao   

  1. National Laboratory of Radar Signal Processing, Xidian University, Xi’an 710071, China
  • Online:2014-07-01 Published:2010-01-03


The azimuth resolution improvement problem is solved via a coherent combination of synthetic aperture radar (SAR) images with the quasi-non-overlapped Doppler bandwidth. Prior to the spectra combination, SAR images should be co-registered, while phase biases induced by topography, atmospheric propagation delays and baseline measurement errors should be calibrated. However, the coregistration accuracy suffers from large Doppler decorrelation caused by the quasi-non-overlapped Doppler bandwidth. Furthermore, the method used to estimate phase biases from interferogram of azimuth pre-filtered SAR image pairs will fail when there is no overlapped spectrum. The fringe simulation and maximum sharpness optimization are adopted to deal with the problems. Accordingly, a novel algorithm to coherently synthesize SAR images is presented. The experiment with the Terra SAR X-band (TerraSAR-X) satellite data validates the performance of the presented method.