InSAR DEM and Spaceborne LiDAR Registration Method in Complex Terrain

Spaceborne Light Detection And Ranging (LiDAR) data can be used as control points for accuracy evaluation and correction of the digital elevation model (DEM) of Interferometric Synthetic Aperture Radar (InSAR), but achieving effective registration of the two is a key prerequisite for fusion applications, especially in areas with complex terrain. Because the changes in plane offset and elevation difference in the region are more pronounced, and are related to the terrain slope. Existing registration models have not fully considered this variation. Therefore, this article proposes a fixed weight model based on terrain slope, combined with a linearized registration model, to solve the offset using the least squares adjustment method. To verify the effectiveness of the registration method, two study areas with different terrain conditions in Spain were selected for testing. The experimental results showed that the root mean square error (RMSE) in the elevation direction of the two study areas after registration reached 0.931 m, and 1.034 m, respectively. The experimental results verified the effectiveness of the algorithm proposed in this paper for the registration of spaceborne LiDAR and InSAR DEM in complex terrain.