Research on fusion strategy of ascending and descending multi-baseline multi-frequency insar results to generate high quality DEM

Compared with DEM generated from single frequency or single baseline repeat pass inteferometric SAR data, the quality of DEM fused with multi-baseline multi-frequency InSAR has been improved effectively. However, the quality of fused DEM by using same orbital and illuminating direction has still been constrained by some factors, among of which the layover and shadow effects are the most important ones, especially in areas where topography reliefs change rapidly. In this paper, we proposed an innovation method to fuse ascending and descending multi-baseline multi-frequency InSAR results to generate higher quality DEMs, which included how to access the effective information in the DEMs generated by using ascending and descending interferometric data, and to complement each other to eliminate potential deficient in layover and shadow areas. The key point of the fusion strategy was to set fusion weight for each resolution element according to the reliabilities, effective mean coherences and resolution ratios of ascending and descending DEMs to be fused. Experiments with real SAR data proved that the proposed method could improve the DEM quality effectively.