The Communication and Measurement Architecture of BDS-3 Global Operations and Services

As the BeiDou Navigation Satellite System (BDS) is developed form BDS-2regional services to BDS-3 global services, the regional-serving GEO and IGSOsatellites are transformed into global-serving MEO satellites. The observation arcof MEO satellites by regional ground stations is about 1/3. The accuracy of MEOorbit determination and time synchronization would become worse, which wouldmake the global positioning accuracy become unacceptable. It is very hard to pro-vide Radio Navigation Satellite System (RNSS) service and effectively managethe satellite constellation. Different from GPS, GLONASS and Galileo adopt-ing a worldwide ground-stations method, BDS-3 creatively established a globaloperations and services architecture with regional stations and Ka-band Inter-Satellite Links (ISLs). The architecture's contributions to BDS-3 include not onlycombined orbit determination and time synchronization, but autonomous navi-gation, global operations and services. The BDS-3 on-orbit operation results arepresented in the paper to verify the designed capabilities. Compared with BDS-2,the orbit determination accuracy is improved from 0.6m to 0.15m, and the time synchronization accuracy is improved from 6.67ns to 1.16ns. Under autonomousnavigation, the 30-day orbit maintenance accuracy reaches 16m and the timesynchronization accuracy reaches 3.74ns. The success rate of data transmissionreaches 99%, and the delay is better than 12.9s. In the future, laser ISLs will beused to enhance the system structure and further improve global operation andservice capabilities.