The pre-processing InSAR feasibility assessment method for wide-area slope displacement monitoring

The pre-processing feasibility assessment of interferometric synthetic aperture radar (InSAR) is important for predicting the quality of InSAR results and guiding the further accurate slope displacement monitoring. However, such kinds of pre-processing (i.e. before the interferometry data processing) assessment method are few, especially for the slope displacement in wide areas. In this article, a method for assessing the pre-processing feasibility of InSAR displacement monitoring is proposed, which mainly takes into accounts the maximum detectable deformation gradients (MDDG), SAR geometric distortions and vegetation coverage. Based on the above factors, the classification criteria employed for InSAR feasibility assessment are built. The approach is applied over Guangxi Province, China a landslide prone area, and an InSAR feasibility map categorized into four categories: high, moderate, low, and very low over the entire study area for pre-processing analysis is obtained. The feasibility results indicate that approximately 77% of areas are classified as very low in the four categories, while the high and moderate feasibility are mainly distributed in urban areas and regions with a NDVI value of less than 0.5. The feasibility results show great agreement with the time series InSAR monitoring results derived from the real Sentinel-1 data in the further validation. This developed methodology is useful for predicting the quality of time series InSAR measurements and providing important information before the SAR data collection and processing, especially in wide-area slope displacement monitoring.