Image quality improvement for underground radar by block migration method

摘要

Abstract: Techniques have been developed which have been imaging optically opaque regions using an electromagnetic wave radar in order to estimate the location of the objects in those regions. One important application of these techniques is the detection of buried pipes and cables. In the case of underground radar, its image quality often becomes low because the nature of the soil is not uniform and an electromagnetic wave is attenuated in soil. Hence, the method which improves the quality of the radar images is required. In this paper, we point out that the quality of underground images can be improved significantly by means of the block migration method. In this method LOT (Lapped Orthogonal Transform) was applied. LOT is a new block transform method in which basis functions overlap in adjacent blocks, and it has a fast computation algorithm. In addition to above, we propose a method of estimating dielectric constant in soil using the processed images. The result of applying the block migration method to the underground radar images are presented. It points out the good capability for the image quality improvement and the application of LOT can improve the influence by blocking and the processing time. Also the dielectric constant in each block can be estimated accurately.!4