Establishment of Vertical Movement Model of Chinese Mainland by Fusion Result of Leveling and GNSS
The National Natural Science Foundation of China(41774004, 41574003, 41904040).
- Available Online: 2022-01-14
Abstract: The leveling and GNSS results are provided important data for studying the vertical movement in mainland. Give full play to the advantages of high-precision leveling points and uniform distribution of GNSS points and help improve the reliability of the vertical movement model. In the process of fusion, that the lack of coincidence points between leveling and GNSS causes joint adjustment of velocity fusion to fail, a fusion method based on final model is proposed. The method consists of two steps. Firstly, establish respective vertical movement model by leveling and GNSS with the method of inverse distance to a power. Secondly, fuse two types of models by weighted average according to the grid point precision and nearest point principle depending on the distance between grid point and measured point. Aiming at the problem that the weight associated with the distance and the velocity precision affects the final model when inverse distance to a power is applied, a method of multiplying the weight is proposed to determine reasonable weight value for each factor. The vertical movement model of Chinese mainland is established by comprehensively using the national first order leveling result, national GNSS geodetic control network and so on. In order to measure the improvement of GNSS results on the vertical movement model, utilize 20% of the modeling points selected from leveling and GNSS points uniformly to statistics the precision of leveling and fused vertical movement model. The results show that the fused vertical movement model has increased by 35.3% in Tibet, 53.6% in other region of China and 50.8% in Chinese mainland. Therefore, GNSS results can improve the precision and accuracy of the leveling vertical movement model, which is especially obvious inside the leveling loop. According to fused vertical movement model, the characteristic of vertical movement is analyzed:North China Plain and Jiangsu-shanghai area are severe subsiding, where the velocity of individual areas is up to 100 mm/a, the North-east of China and Tibet areas are uplifting, and the maximum velocity exceeds 5 mm/a in some local area, the vertical movement in other areas is relatively stable.
|Citation:||GUO Chunxi, GUO Xinwei, NIE Jianliang, WANG Bin, LIU Xiaoyun, WANG Haitao. Establishment of Vertical Movement Model of Chinese Mainland by Fusion Result of Leveling and GNSS[J]. Geomatics and Information Science of Wuhan University. doi: 10.13203/j.whugis20200167|