Abstract
The precision in measuring SAR image shift between looks using three look correlation is analyzed and verified. In this method, in order to improve the measurement precision and to produce optimally focused SAR imagery, n pairs of two relative image shifts among three looks are measured and selected by the rule that the difference between the pair should be less than a threshold of T.
So, the precision of three look correlation is described as a function of, n, T and σ, where σ is a newly defined measure of difficulty in measuring image shift. This function leads to the optimal threshold that maximizes the precision in the method.
The results of the image shift measurement test shows that the proposed method can reduce the measurement error to up to 2/3 of a conventional one caused by two look correlation.
