Automated Robust Procedure for SAR Image Filtering and Preliminary Analysis

摘要

In some practical situations it is often necessary to process radar images for which a priori information about noise characteristics is limited. Evaluating these characteristics, in particular, estimating speckle noise variance, is quite a complicated and time consuming task. In order to carry out both tasks efficiently enough for typical practical situations an automated robust procedure for SAR image filtering and preliminary analysis is proposed. It consists of several stages: a) blind evaluation of speckle relative variance for the original image, b) pre-processing using the local statistic Lee filter, c) blind evaluation of the residual noise relative variance for the pre-processed image, d) post-filtering. It is shown that the proposed procedure provides rather accurate estimations of noise characteristics. The effectiveness of the filtering scheme is confirmed for both simulated and real scene SAR images.