A model based bias field correction algorithm for SAR sea ice image

A novel algorithm using multi-exponential model is presented in this paper for correcting the intensity bias field, produced by the variation of SAR incidence angle along SAR range direction, in SAR sea ice image. In the algorithm, the image's mean values along SAR azimuth direction are calculated firstly. Then an one-dimensional correction field is modeled by a multi-exponential model. Whereafter, the one-dimensional correction field is calculated by applying entropy minimization method. After that the original image is corrected by the two-dimensional correction field derived from the one-dimensional correction field. The experiment result indicates that the proposed algorithm is effective in correcting SAR sea ice image's incidence angle bias field. Besides, the proposed algorithm has better correction result than Karvonen's method and it does not need the incidence angle information of the image pixels.