Document Type : Original Article
School of Surveying and Geospatial Engineering, University of Tehran, Tehran, Iran
Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, the Netherlands
During the last decades, time-series interferometric synthetic aperture radar (InSAR) has emerged as a powerful technique to measure various surface deformation phenomena of the earth. Early generations of time-series InSAR methodologies, i.e. Persistent Scatterer Interferometry (PSI), focused on point targets, which are mainly man-made features with a high density in urban areas and associated infrastructure. Later, methodologies were introduced aiming to extract information from other targets known as distributed scatterers (DS), which are associated with ground resolution cells occurring mainly in rural areas. For some terrain types, such as agricultural terrain or pastures, the feasibility of DS-methodologies is not straightforward. In this paper, we investigate the feasibility of DS exploitation in pasture areas over a case study area over a solution salt mining-induced subsidence field in Veendam, the Netherlands. Based on the temporal coherence behavior of the DS-pixels in the pasture areas, we assess the feasibility of exploiting the DS-pixels by different satellite missions. The results show that assuming a three-year stack of data, the information content in DS-pixels from current C-band and X-band missions is not enough for the successful utilization of their entire time-series. However by using intermittent series, e.g., by processing individual coherent periods, the results indicate that DS-pixels can be exploited: based on the proposed decorrelation model, the short repeat times of Sentinel-1 (6 or 12 days) results in a sufficient number of coherent interferograms over each winter period, enabling DS exploitation even over agricultural and pasture areas.