Global 30m SRTM DEM correction product for vegetation areas in 2000

SRTM(shuttle radar topography mission) DEM(digital elevation model) It is a high-precision terrain product that covers a near global scope and is widely used in disciplines such as hydrological survey, disaster assessment, and ecological protection. However, previous studies have shown that SRTM DEM has significantly higher terrain in forest areas compared to real ground. The absorption and reflection of radar signals by tree branches, leaves, trunks, and other factors, as well as the influence of terrain such as slope and orientation, all contribute to errors in SRTM DEM data. This study collected over 150000 km2 of airborne LiDAR data worldwide as ground truth to correct the SRTM DEM of vegetation covered areas. Firstly, establish the regression relationship between SRTM DEM error and slope, vegetation coverage, and canopy height under different vegetation types, and obtain the error model. Based on this error model, the global SRTM error is calculated by combining global slope, vegetation coverage, tree height, and vegetation type, and then the SRTM data is corrected. The results showed that in vegetation covered areas, the uncorrected SRTM DEM had a height error of approximately 6 meters, while the corrected SRTM DEM significantly eliminated the influence of vegetation and terrain on the SRTM DEM, reducing the error to approximately 0 meters.