Comparison of Integrating GF-7 and ICESat-2 Laser Altimetry Data with High-resolution Stereo Images for Stereo Mapping

Abstract. Currently, two types of satellite laser altimetry systems are in operation: the full waveform linear system and the single-photon-counting system, which exhibit significant differences in both data format and processing methodologies. It remains uncertain which satellite laser altimetry technology offers greater advantages in assisting stereo mapping of high-resolution optical imagery. To evaluate the effectiveness of those two satellite laser altimetry technologies in supporting optical imagery stereo mapping, this study extracted laser elevation control points from both GF-7 satellite and ICESat-2 laser altimetry data, and designed a specialized bundle adjustment workflow for GF-7 satellite stereo images incorporating laser elevation control points. Comparative experiments were conducted across both flat and mountainous regions. Results demonstrate that laser elevation control points derived from both GF-7 satellite and ICESat-2 effectively improved the elevation accuracy of stereo mapping of GF-7 satellite images. However, the ICESat- 2 laser altimetry data has advantages in quantity and distribution, and the combined bundle adjustment accuracy of the two survey areas is slightly better than that of the GF-7 satellite laser altimetry data.