Image coregistration in SAR interferometry only by means of arithmetic operations

An alternative interpolation technique for SAR image coregistration in interferometric processing is formulated and described. The proposed algorithm is based on the 1- D Farrow interpolator and, when combined with an adequate implementation, it involves a smaller computational burden than the conventional method and yields high accuracy. Basically, this technique enables to carry out the coregistration without resorting to a set of functional weights, and it only requires arithmetic operations and 2-D FFTs. This paper includes several results and comparisons that confirm its validity: the proposed technique is combined with two different polynomial interpolation procedures (Taylor and Chebyshev); bounds on its interpolation error in the 1-D and 2-D cases are derived; and, additionally, it is tested numerically with a synthetic image.