Performance validation of High Mountain Asia 8-meter Digital Elevation Model using ICESat-2 geolocated photons

High Mountain Asia (HMA), recognized as a third pole, needs regular and intense studies as it is susceptible to climate change. An accurate and high-resolution Digital Elevation Model (DEM) for this region enables us to analyze it in a 3D environment and understand its intricate role as the Water Tower of Asia. The science teams of NASA realized an 8-m DEM using satellite stereo imagery for HMA, termed HMA 8-m DEM. In this research, we assessed the vertical accuracy of HMA 8-m DEM using reference elevations from ICESat-2 geolocated photons at three test sites of varied topography and land covers. Inferences were made from statistical quantifiers and elevation profiles. For the world's highest mountain, Mount Everest, and its surroundings, Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE) resulted in 1.94 m and 1.66 m, respectively; however, a uniform positive bias observed in the elevation profiles indicates the seasonal snow cover change will dent the accurate estimation of the elevation in this sort of test sites. The second test site containing gentle slopes with forest patches has exhibited the Digital Surface Model (DSM) features with RMSE and MAE of 0.58 m and 0.52 m, respectively. The third test site, situated in the Zanda County of the Qinghai-Tibet, is a relatively flat terrain bed, mostly bare earth with sudden river cuts, and has minimal errors with RMSE and MAE of 0.32 m and 0.29 m, respectively, and with a negligible bias. Additionally, in one more test site, the feasibility of detecting the glacial lakes was tested, which resulted in exhibiting a flat surface over the surface of the lakes, indicating the potential of HMA 8-m DEM for deriving the hydrological parameters. The results accrued in this investigation confirm that the HMA 8-m DEM has the best vertical accuracy and should be of high use for analyzing natural hazards and monitoring glacier surfaces.