1. Research on UAV Free Image Control Aerial Survey Method Based on Global Gravity Field Model.
- Author
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PENG Xiaoqing, WU Zhenli, and FANG Huibing
- Subjects
AERIAL surveys ,GEODETIC satellites ,AERIAL photogrammetry ,MARKOV random fields ,GLOBAL Positioning System - Abstract
To address the issue of needing drone aerial photogrammetry in certain projects where there is a lack of basic control points around the survey area, or it is difficult for personnel to enter the area to set up photo control points, this paper proposed a fast aerial survey method for drones without photo control based on global gravity field models, and the accuracy of this method was verified through experiments. The research used three global gravity field models: EGM2008, XGM2019, and EIGEN-6C4, to calculate the height anomalies in six experimental areas and converted the geodetic heights in the image exterior orientation elements to normal heights, which were then input into the aerial survey software for aerial triangulation and 3D modeling. The analysis of the results shows that, the elevation accuracy of the photo control-free aerial survey results based on the EGM2008, XGM2019, and EIGEN-6C4 models is between 10 ~ 20 cm, which meets the requirements of 1:2 000 mapping precision. To further improve the accuracy of the results, this paper adopted a method based on the EIGEN-6C4 gravity field model and the "remove-fit-restore" normal height calculation method, which converted the geodetic heights in the exterior orientation elements of the images obtained by the drone aerial survey system into normal heights. The method calculated the height anomalies of 16 GNSS leveling points across the country, fitted a normal height model for the experimental area, and achieved higher accuracy drone aerial surveys without photo control. The experimental results show that, the elevation accuracy of the photo control-free aerial survey results based on the EIGEN-6C4 model "remove-fit-restore"method can reach the centimeter level, which is higher than the method based only on the EGM2008, XGM2019, and EIGEN-6C4 gravity models, and can meet the requirements of 1:500 mapping precision. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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