Quality Assessment of Digital Elevation Model Derived from ALOS PALSAR Interferometry

Popular public domain DEM includes Shuttle Radar Topography Mission (SRTM) with 3 arcsec grid and Terra ASTER GDEM with 1 arcsec grid, which can provide with fundamental topographic information. Finer grid DEM than ASTER GDEM may be required in some researches, but cloud-free stereo pairs of optical sensor images with very fine spatial resolution may be needed to create such fine DEM, and such satellite image data is usually costly. An alternative practical method of DEM calculation is SAR interferometry using satellite SAR data. The study shows an example of DEM calculation using ALOS PALSAR data (PALSAR DEM) for a mountainous area in UAE and Oman, and quality assessment of the DEM through comparison with SRTM and ASTER GDEM as well as field GPS data. Several ALOS PALSAR interferometry pairs with appropriate parameters for DEM calculation were selected, and calculated DEMs were stacked to decrease the effect of phase noise and to create 10 m/pixel grid DEM. By using 10m grid PALSAR DEM for terrain correction, detail complete gravity anomaly was obtained in northwestern Oman Mountains.