Geometric Correction on SAR Imagery
Ai Ling Choo, Yee Kit Chan, Voon Chet Koo · 2012
SAR images are generated through signal processing using the data collected by the SAR system from the target scenes on earth surface. However the SAR images generated may contain errors or distortions which cause the data in the present image to be inaccurate. These errors or distortions present in the SAR image also known as geometric distortion. Geo- metric distortions exist in all remote sensing images and broadly related to the target, sensor and platform. The objective of this research project is to reduce the error of SAR images through implementation of geometric correction on SAR. Geometric correction can be done by reposition of pixels form the uncorrected image location to the reference grid through geometric operations. There are few types of geometric correction methods such as registration, rectiflcation, geocod- ing and orthorectiflcation. The three main process of geometric correction are mathematical distortion model, coordinate registration and resampling. These three components also known as warping process. Mathematical distortion model such as polynomial distortion model has been generated using MATLAB for the geometric correction purpose. After coordinate registration the SAR image will be resampled. There are few types of resampling method such as nearest neighbour, bilinear interpolation and cubic convolution.