ASAR and PALSAR sensors assessment for landslide detection, monitoring using differential interferometry in Zagros Mountains

Launching satellites with Synthetic Aperture Radar (SAR) sensors onboard, purposely built for differential interferometry (D-InSAR) applications opened new opportunities for mapping and monitoring slow ground deformations and even high speed landslides, for the updating of regional landslide inventories as well as retrieving time series of landslide movements. The present work has been done by using DInSAR method, with objection of performance assessment of two radar sensors in order to detecting, monitoring and landslide inventory mapping in Dena Mountain of Zagros located in south of Isfahan province. For this purpose two sets of images including 17 and 21 RADAR images of PALSAR and ASAR sensors from ALOS and ENVISAT satellites were chosen and processed by D-InSAR method. The preliminary processing result showed that 16 interferometer images were suitable for the next processing stages from all applied data sets. The outcome of interfrogram analysis along with field checking showed that 914 segments are marked as landslides anomaly over the area of 13578 ha. The maximum land sliding activities was identified as 1.58 meter vertical displacement during May 2010 to September 2011. Furthermore, results showed differential interferometry method applied for above mentioned frequencies has sufficient accuracy and conform efficiency for landslide detection, monitoring and distribution mapping compared to other methods (field survey in extend area, aerial photo and optical satellite images). Out of this two frequency, low frequency of PALSAR images has better ability in landslide zonation due to its capabilities such as longer wavelength and reduced incoherency. Where the high frequency of ASAR images can offer more details of the landslides due to its shorter wavelength.