A Novel DEM Extraction Method Based on Chain Correlation of CSAR Subaperture Images

Circular synthetic sperture radar (CSAR) can observe the target in 360° and obtain the target's total scattering information. By dividing the CSAR imaging data into subapertures, the target digital elevation model (DEM) information can be directly obtained. Aiming at the problems existing in the division and selection of subapertures when acquiring DEM, this article proposes a chain correlation method. First, the echo data of the full aperture is divided into multiple subapertures; then, the correlation between the two adjacent subapertures is used to perform correlation processing on the subaperture image, and then the DEM information is obtained. The chain correlation method proposed in this article takes advantage of the stronger correlation between adjacent subapertures, improves the accuracy of the algorithm, and effectively improves the overall efficiency of the algorithm. Finally, the effectiveness and reliability of the proposed method is verified by different measured data, and it is the first time our own collected Ku-band experimental data are used.