单频到五频多系统GNSS精密单点定位参数估计与应用

全球导航卫星系统(GNSS)已发展至多频多系统时代,特别以我国北斗卫星导航系统(BDS)为代表的四大全球导航卫星系统可全天时、全天候播发十几个频率的伪距、相位和多普勒等观测信息。多频多系统GNSS为用户提供更多的观测数据和组合选择,为精密定位、导航和授时(PNT)应用带来了新的机遇,如高精度位置服务、大地测量、空间天气和灾害监测等。但多频多系统GNSS观测为精密单点定位(PPP)组合模型和系统偏差及大气延迟估计等带来诸多问题和挑战。本文给出了单频到五频多系统GNSS精密单点定位(PPP)模型,估计和评估了单频到五频多系统GNSS PPP定位精度、接收机钟差、对流层延迟、卫星和接收机硬件延迟,以及频间偏差。给出了GNSS PPP最新应用进展,包括GNSS气象学、电离层模拟、时间频率传递、建筑物安全和地震监测及其应用。结果表明,多频多系统极大地提高了GNSS PPP参数估计的精度和可靠性,具有重要的应用价值。最后给出了多频多系统GNSS PPP应用前景与展望。

Parameters estimation and applications from single- to five-frequency multi-GNSS precise point positioning

Global navigation satellite system (GNSS) has been developed into the era of multi-frequency multi-GNSS, particularly four global navigation satellite systems including China's BeiDou navigation satellite system (BDS) with broadcasting more than ten frequencies of all-day and all-time observation information about pseudo-range, phase and Doppler. Multi-frequency multi-GNSS provides users more observations with more combination choices and new opportunities for the applications of precise positioning, navigation and timing (PNT), such as high precision location-based services, geodesy, space weather and disaster monitoring. However, the multi-frequency and multi-GNSS brings numerous questions and challenges, e.g. the combination models and system bias of GNSS precise point positioning (PPP) as well as atmospheric delay estimation. This paper presents multi-GNSS PPP models from single- to five-frequency observations. The PPP performance, receiver clock difference, tropospheric delay, satellite and receiver hardware delay, and inter-frequency bias are estimated and assessed from single- to five-frequency multi-GNSS observations. The latest advances on GNSS PPP applications are presented, including GNSS meteorology, ionospheric modeling, time-frequency transfer, structure health and earthquake monitoring as well as their related applications. The results show that the multi-frequency multi-GNSS has greatly improved the accuracy and reliability of PPP in parameters estimation, which has an important application value. Finally, the application prospective and outlook of multi-frequency multi-GNSS PPP are given and discussed.