<![CDATA[This study analyzes the effect of UAV LiDAR flight altitude on surface model accuracy in steep terrain mining areas. Data were acquired at flight altitudes of 100 m, 150 m, and 200 m above ground level. Point cloud density was evaluated using point density and point spacing, while surface model accuracy was assessed using the Root Mean Square Error (RMSE) based on Independent Control Points (ICPs). The results showed that a flight altitude of 100 m produced a horizontal radial RMSE (RMSEr) of 0.064 m and a vertical RMSE (RMSEz) of 0.038 m. At 150 m altitude, the RMSEr and RMSEz values were 0.071 m and 0.065 m, respectively, whereas at 200 m altitude the RMSEr remained 0.071 m and the RMSEz increased to 0.124 m. The decrease in vertical accuracy was accompanied by a reduction in point density from 1124.25 points/m² to 155.75 points/m² and an increase in point spacing from 2.98 cm to 8.01 cm. The results indicate that increasing flight altitude has a greater influence on vertical accuracy than on horizontal accuracy of the surface model. Based on the accuracy classification of the Indonesian Geospatial Information Agency (BIG) Regulation No. 15 of 2014, the 100 m and 150 m flight altitudes satisfied the requirements for a 1:1,000 base map Class 1, whereas the 200 m flight altitude satisfied the requirements for a 1:1,000 base map Class 2. These findings indicate that all tested flight altitudes remain suitable for topographic mapping in mining areas.]]>
