GPS Campaigns for Validation of InSAR Derived DEMs

Interferometric Synthetic Aperture Radar (InSAR) is a rapidly evolving technique. Spectacular results that are obtained in various fields, such as the monitoring of earthquakes, volcanoes, land subsidence and glacier dynamics, as well as in the construction of Digital Elevation Models (DEMs) of the Earth's surface and the classification of different land types, have demonstrated its strength. As InSAR is a remote sensing technique, it has various error sources due to the satellite positions and attitude, atmosphere, and others, so it is important to validate its accuracy, especially for the DEM derived from SAR images before it can be used for various applications such as disaster prevention, flood mapping, and emergency map. In this study, Real Time Kinematic (RTK) GPS positioning and Kinematic GPS positioning were chosen as tools for the validation of InSAR derived DEM. The results showed that Kinematic GPS positioning had greater coverage at field test, i.e. larger number of usable sampling points than RTK GPS. However, tracking satellites and transmitting a data between reference-rover, under trees are still pending tasks to be overcome in GPS positioning techniques. Additionally, Airborne Laser Scanning (ALS) is expected to be an alternative as an effective tool for the validation of DEMs.