Research on the elevation calculation method of unmanned aerial vehicle aerial survey image control points based on the EMG2008 model

In the field of large-scale topographic mapping, unmanned aerial vehicle (UAV) aerial surveying has become the mainstream technical means due to its advantages of high efficiency and flexibility. However, in the absence of regional conversion parameters, the determination of control point elevations still highly relies on the traditional multi-control point joint measurement method, which leads to problems such as low efficiency, sharp cost increase, and safety hazards when operating on complex terrains. In response to the above-mentioned bottlenecks, this paper proposes a method for calculating the elevation of image control points based on the EGM2008 correction model. By innovatively adopting the single-point joint measurement technology to determine regional elevation anomalies and combining it with the EGM2008 Earth gravity field model, it realizes the rapid solution of batch image control point elevations. Experimental data show that through strict theoretical derivation, scene measurement verification and error analysis, this method can accurately meet the requirements of elevation accuracy for image control points in large-scale topographic mapping, effectively reduce the operation difficulty and safety risks under complex terrain conditions, and improve the efficiency of aerial surveying operations.