GPS/BDS精密单点定位技术在滑坡变形监测中的应用研究

Application of GPS/BDS Precise Point Positioning Technology in Landslide Deformation Monitoring

分别探讨了GPS精密单点定位技术、GPS/BDS精密单点定位技术及BDS精密单点定位技术在地形较为陡峭、有部分卫星被遮挡的滑坡体特殊环境中的应用能力。选用四川西山村8个监测站,总时长跨度16个月的观测数据进行试验及分析,结果表明:西山村滑坡体整体正以平均9.2mm/月的速度向南滑动,并伴随着垂向上的整体下沉。精度区间统计结果显示,平均5.93h时长的GPS精密单点定位的解算精度基本能达到较高水平且相对稳定,可以有效监测变形较缓慢的滑坡体。GPS/BDS的解算结果的精度接近于单GPS的水平,但由于BDS的数据可利用率整体上不稳定,拉低了GPS/BDS的解算结果的整体精度,表明了当前的单BDS精密单点定位的精度受地形等外界环境变化的影响更大。利用观测时长及数据的可利用率指标加权处理解算结果,降低了观测质量不高的结果对整体结果的贡献比,提高了定位结果的精度和容错率。

In this paper, the application ability of GPS PPP, GPS/BDS PPP and BDS PPP technology in the special environment of steep terrain with part of satellites blocked is discussed. Eight monitoring stations in Xishan village, Sichuan province are selected for the experiment and analysis with the observation data of a total span of 16 months, the results show that the overall slope of Xishan village is sliding southwards at an average speed of 9.2 mm/month, accompanied by an overall vertical subsidence. The results of precision interval statistics show that the precision of GPS precision point positioning with an average length of 5.93 hours can basically reach a high level and be relatively stable, and it can effectively monitor the slope body with slow deformation. Although the results of GPS/BDS are close to the level of single GPS, with the unstability of the data availability of overall BDS precise point positioning, the overall accuracy of GPS/BDS solution is reduced, which indicates that the accuracy of BDS precise point positioning can be more affected by the change of external environment such as terrain. Using observation duration and data availability index to weight process results of calculation, the contribution ratio of low observation quality results to the overall results is reduced, and the accuracy and fault tolerance rate of positioning results are improved.