High-Accuracy Laser Altimetry Global Elevation Control Point Dataset for Satellite Topographic Mapping

As the accuracy of satellite laser altimetry is susceptible to real-time atmospheric conditions, within footprint topography fluctuation, detector noise, and so on, we proposed a method by comprehensively analyzing the laser ranging error and evaluation labels to extract high-accuracy elevation control points that is suitable for satellite imagery-based topographic mapping applications. Using the ICESat laser altimetry data, a global high-accuracy laser altimetry dataset, including more than 60 million control points, based on the laser altimetry ranging error model and waveform quality analysis is proposed in this article. For land areas, except for areas of water, snow/ice, and polar ice sheets, the dataset can provide the elevation control points for worldwide satellite topographic mapping using high spatial resolution imageries or other science research that depend on accurate Earth’s elevation information. We further used airborne LiDAR data from six study areas around the world to carefully validate the datasets’ accuracy. The results showed that this dataset can meet the accuracy requirement of global mapping using high spatial resolution satellite imageries in terrains with a slope below 25°. Compared to the raw dataset, the proportion of footprint elevations that conform to the accuracy standard (0.5 m @ slope < 2°, 1.5 m @ 2° $\le $ slope < 6°, and 3 m @ $6^{\circ } \le $ slope $< 25^{\circ }$ ) is increased from 68.24%, 59.97%, and 26.52% to 87.58%, 90.04%, and 83.91%, respectively. This method can assure that its extracted results’ accuracy is either very close to or better than that obtained by the methods proposed in relevant studies, with a much larger number of laser footprints (LFs) that have been reserved.