Comparative Study on the Mosaic Methods of AW3D30 v2.2 and ASTER GDEM v3

Aiming at the problem that the current AW3D30 data has a cavity outside 60° north and south latitude, In experiments, different fusion methods, including direct mosaic, inverse distance weighting, inverse distance square weighting, gaussian inverse distance weighting and gaussian inverse distance square weighting methods, were compared using ASTER GDEM v3 and AW3D30 v2.2 data sets in the area around 60°north latitude. The fusion results are compared by longitudinal section and surface error information entropy. The results show that: 1) Among the five methods, the direct mosaic boundary is obvious, the other four methods adopt curve transition, and the transition at the boundary is relatively natural; 2) Further comparison in the four curve edge-connection modes, the two weighting methods using Gaussian function are better at the northern boundary of the transition zone. The mean value of the elevation difference is 1.3 m. The inverse distance weighting and the inverse distance square weighting effect are poor, and the elevation difference is poor. The mean value is 16.0 m; 3) Finally, using the surface error information entropy to compare the two Gaussian methods, the fusion result of Gaussian inverse distance weighting method is better, and the average surface error information entropy is 3.22 bit. Therefore, among the five fusion methods, the Gaussian inverse distance weighting method has the best effect.