GPS单双频混合方法在地表形变监测中的应用

Single-and Dual-Frequency Mixed Mode GPS Network for Ground Deformation Monitoring

在地表形变监测中,若全采用双频GPS则费用过高,若全采用单频GPS则因电离层误差得不到较好消除而导致精度下降。针对这一问题,本文采用GPS单双频混合模式,即通过解算监测区域外围的双频GPS数据获取该区域大气延迟误差残余量,将其用于改正内部单频监测站点数据,从而在降低硬件成本的同时改善监测精度。利用研发的软件对实测数据进行处理分析,结果表明,改正后的高程分量精度优于1.24cm,三维位置精度优于1.59cm,较单频方法提高24%;且当单频站点位于双频站点组成的区域内部时改正效果更好,高程分量精度优于0.95cm,三维位置精度优于1.2cm,精度改善比例达到30%,最高可达58%。

Ground subsidence monitoring is costly if we use dual-frequency GPS receivers for all stations while positioning precision will decrease if we use single-frequency GPS receivers for all stations, as first-order term ionospheric error cannot be eliminated by combining observations. To solve this problem, we use a single- and dual-frequency mixed mode for subsidence monitoring. We get the residuals for atmospheric delay error by processing dual-frequency stations around the subsidence monitoring region and use the residuals to correct the single-frequency monitoring station observations. This mixed mode approach reduces hardware costs and improves the positioning precision. We processed real subsidence monitoring GPS data based on results show that the precision in the U direction was software developed by the authors. Numerical better than 1.24 cm, three-dimensional position precision was better than 1.59 cm, and precision was improved 24% overall using the single dual-fre- quency mixed mode. Furthermore, the precision results were better when single frequency monitoring stations are located within the dual-frequency station region, the precise in U direction was better than 0.95 cm, three-dimensional position precision was better than 1.2 cm, precise improved 30% overall and in the best case conditions, improved to 58%.