PHASE DIFFERENCE AUTO FOCUSING FOR SYNTHETIC APERTURE RADAR IMAGING

摘要

The present invention discloses an autofocusing method and apparatus for Synthetic Aperture Radar which employs operation on two or three subarrays of the SAR compressed data to estimate quadratic and cubic phase errors in the data. Focusing of the SAR array may then be accomplished by removing the estimated phase error from the data to sharpen the image. Phase error is estimated by FFT filtering product arrays formed by multiplying the complex conjugate of one subarray by another of the subarrays to form a correlation function. The correlation functions are integrated. A peak detection of the integrated correlation functions yields a peak location in the filter which is proportional to the phase error which may then be calculated.