北斗GRAPHIC单频PPP全球时空特性分析与评估OA

With the widespread adoption of low-cost BeiDou Navigation Satellite System(BDS)application,the group and phase ionospheric calibration(GRAPHIC)single-frequency precise point positioning(PPP)model can provide decimeter-level positioning results,which provides an effective solution for high-precision location services for low-cost single-frequency devices.In order to analyze the difference of positioning performance of single BDS GRAPHIC single-frequency PPP in different regions of the world and in different ionospheric active periods,this paper comprehensively analyzed the spatial-temporal characteristics of the model in low,middle and high latitude region and ionospheric quiet and active periods,during the test period,by using the data of 50 Multi-GNSS Experiment(MGEX)stations evenly distributed.In the analysis of spatial characteristics,the positioning accuracy of BDS GRAPHIC single-frequency PPP is the best in the mid-latitude region(about 0.6 m),the worst in the low-latitude region(about 1.0 m),and in the high-latitude region,it shows good in the north and bad in the south;In the analysis of temporal characteristics,the positioning accuracy of BDS GRAPHIC single-frequency PPP is not much different between ionospheric quiet period and active period,only about 7 cm;In terms of convergence,the horizontal convergence speed is not significantly affected by the ionospheric activity,but the elevation direction converges faster in the ionospheric quiet period,especially in the high latitude region.