Time Series Offsettracking of Baige Landslide Based on Sentinel-2 and Landsat 8
摘要
Objectives: Time-series offset tracking is a critical technique for landslide monitoring with optical images, which has been applied worldwide successfully in the recent years. The continued monitoring of landslide can provide early warning and emergency informationfor the nature hazard prevention. However, the resolution in the temporal domain is restricted by the single-platform datasets, especially in the case of bad weather. To solve this issue, this paper used the multi-source optical images, including Sentinel-2 and Landsat 8, to generate the long time-series deformation of landslides. The high resolution of deformation in the temporal domain can help us know more about the development process of the landslide. Methods: The method is executed based on the idea of small baseline subset (SBAS) in the interferometric synthetic aperture radar (InSAR) technique, aiming to reduce the influence of the temporal baseline and noise on the signal noise ratio (SNR). Meanwhile, to obtain the time-series deformation of the multi-platform optical images, we used a weighted singular value decomposition (SVD) method to obtain the time-series deformation of the multi-platform optical images. In this paper, a collection of 11 Sentinel-2 and 16 Landsat 8 datasets are used to generate two-dimensional horizontal time-series deformations of Baige landslide from 2014-11 to 2018-09. First, we calculated the time-series offset tracking of the single platform, i.e., Sentinel-2 and Landsat 8, and the dual-platform by considering the selection of the image pair, search window size, step length, and the threshold of SNR respectively. And a time-series deformation of 27 images are obtained with offset tracking technique of the dual-platform. Second, the accuracy of the results for the single-platform and the dual-platforms is evaluated by two commonly used methods:stable area statistics with a priori knowledge and cross-validation of independent datasets. Then, the developmental stages of B