A robust phase calibration algorithm for a dual-channel along-track interferometric FMCW SAR

A new robust phase calibration technique to estimate and correct the range-dependent phase differences between two receivers in an FMCW ATI SAR has been developed. Based on linear regression, this calibration scheme jointly estimates the phases for both SAR receivers and reproduces the range-dependent phase ripple seen in the ATI interfergrams. After applying the calibration results to the post-processing of SAR data, the phase ripple seen in the previous interferograms is significantly reduced (by about 10 dB). This work has relevance to implementing compact low-cost FMCW interferometric SAR systems for geophysical research measurements.