A study on high-precision DEM generation using ERS-envisat SAR cross-interferometry

Cross-interferometry using ERS-2/Envisat is a method for generating the high-quality interferogram in spite of a long baseline. Since the height ambiguity on long baseline is calculated about 5m, the high precision DEM could be generated. In this paper, we proposed an efficient method for processing the cross-interferometry and attempted to generate high-precision DEM based on cross-interferometry using ERS-2/Envisat SAR data in flat Alaska area and compared with NED(National Elevation Dataset) DEM. As a result, the difference between CInSAR(Cross-Interferometry SAR) DEM and NED DEM has been calculated to 2.63m of standard deviation due to error of NED DEM on the stage of generating differential interferogram. However, the standard deviation of difference on the whole test area showed about 1m and it is similar to NED DEM. The result of precision is similar because the test area is flat and high-quality DEM exists. However, in spatial frequency analysis, CInSAR DEM showed high power spectrum on the high frequency region above 0.08 rad/m(about 40m) but NED DEM didn't. It means that CInSAR DEM constructed to have 16m resolution and two-and-a-half times precise than NED DEM in spatial frequencies aspect. In conclusion, Cross-interfer- ometry is generate high-precision DEM in flat-area.