Digital Elevation Model (DEM) Generation with Repeat Pass Interferometry Method Using TerraSAR-X/Tandem-X (Study Case in Bandung Area)

Abstract

Technological developments have developed to monitor and map the activities of earth movements. One of the technologies developed for deformation monitoring is using Synthetic Aperture Radar Interferometry (InSAR) technology. InSAR is an effective method for measuring surface deformation with sub-centimeter precision. Image processing with this technique produces DEM. DEM is a 3D digital elevation model that shows the physical situation and topography of the earth which is defined as a digital model dimensions obtained from surface elevation using the selected interpolation method. The resulting DEM will be validated in the test area using the appropriate reference DEM. The case study area used is the Bandung area. Data processing with SNAP software where image recording on June 12, 2018 is used as a master image and June 23, 2018 as a slave image. The difference in angle of incidence between the two images is 420 where the master image is Tandem-X and slave image Terrasar-X. Acquisition scenario for DEM generation, several data sets obtained in different TerraSAR-X modes with different incidences of angle combinations in different of times. The baseline value of these two data is 322 meters. Stages of processing starting from coregistration, interferogram generation, goldstein phase filtering, phase unwrapping, phase to elevation and geocoding with DEM output for the Bandung region. From 24 field data points, 20 points are use as validation correction and 4 points as accuracy correction. The DEM generated from the TerraSAR-X corrected using regression corrected and shifting correction. DEM generation from shifting correction is better than regression corrected with absolut error 3,24 m and RMSE 5,52 m.