Spaceborne SAR Time-Series Images Change Detection Based on Log-Ratio Operator

Spaceborne SAR has the advantage of stable revisit period to obtain high-resolution images. For the long-time time-series images, the change information in the fixed area can be extracted by using the change detection technology. It is of great significance for environmental monitoring, disaster loss assessment and production capacity assessment. Most of the existing methods are aimed at large areas, and there are few target-level change detection methods. Therefore, this paper proposes a Log-Ratio (LR) operator based change detection method using spaceborne SAR time-series images to obtain the target-level change information. In this method, one of the time-series images in the sequence is taken as the reference image, and the change image is obtained by taking logarithm of the ratio of the input and reference image. Then, the CFAR algorithm is used to complete the detection on the change image. The proposed method is verified by the Sentinel1 dataset.