广域瞬时厘米级精密单点定位和服务系统

Wide-Area Instantaneous cm-Level Precise Point Positioning:Method and Service System

精密单点定位技术(precise point positioning,PPP)虽可以提供全球厘米级定位,但是需要数十分钟实现收敛,而PPP-实时动态定位(real-timekinematic,RTK)则依赖区域参考站以提供大气延迟改正信息,限制了系统服务范围。实现了一种多频多模观测值PPP方法,仅需要卫星轨道、钟差和信号偏差即可实现全球范围内的瞬时厘米级定位,解决了PPP收敛慢、PPP-RTK服务范围有限和成本高的难题。结合现有星基增强改正数编码和播发方式,构建了一个兼容北斗PPP-B2b服务的广域瞬时厘米级服务系统,并评估了其轨道、钟差和信号偏差等增强信息精度。中国区域静态和车载动态数据验证结果表明,该系统可以95%的置信率在1min内实现厘米级精密定位,可满足自动驾驶等领域对快速、高精度和高可信定位的需求。

Objectives:Although the precise point positioning(PPP)can provide global cm-level positioning,it takes tens of minutes to converge.While PPP-RTK(real-time kinematic)relies on regional reference sta-tions to provide atmospheric delay corrections to accelerate the convergency,however,only the regional service can be provided.Methods:PPP with multi-frequency and multi-GNSS observations is presented,and only the satellite orbit,clock and observable-specific signal bias(OSB)are needed to achieve instanta-neous cm-level positioning.This approach solves the problems of slow convergence of PPP as well as the limited-service scope of PPP-RTK.Furthermore,a wide-area instantaneous cm-level service system com-patible with BDS(BeiDou satellite navigation system)PPP-B2b service is proposed,and the perfor-mance of real-time orbit,clock and OSB is evaluated.Results:The results of static and in-vehicle kinematic data in China confirm that the system can provide cm-level precision positioning within 1 min.Conclu-sions:It's implied that our system bears the ability to meet the needs of fast,high-precision and high-confi-dence positioning in autonomous driving and other fields around the world.