Application of ERS and Envisat cross-interferometry to generation and accuracy assessment of digital elevation model over northern Alaska

The accuracy of a digital elevation model (DEM) generated from synthetic aperture radar (SAR) interferometry (InSAR) crucially depends on the length of the perpendicular baseline between SAR acquisitions. ERS-2 and Envisat cross-InSAR (CInSAR) are superior methods to create high precise DEM because the perpendicular baseline can be extended sufficiently long by compensating a slight difference in radar carrier frequency. We have assessed the accuracy of DEM generated by using ERS and Envisat satellite CInSAR techniques using the ice, cloud, and land elevation satellite global elevation data, which has an absolute vertical accuracy of about 2 cm. The study area is high flat land covered up with ice and snow in northern Alaska. Our result shows that the CInSAR-derived DEM can achieve an accuracy of about 0.50 m. This is much better than that of the National Elevation Dataset (DEM) (1.95 m) and is slightly lower than that of the airborne InSAR DEM (0.36 m).