Performance Assess of BDS-3 PPP-B2b Signal Service and Its Application in Precipitable Water Vapor Retrieval

The BDS-3 PPP-B2b signal provides the high-precision real-time precise point positioning (RTPPP) service for China and its surrounding areas, without relying on the internet communication to data reception. This technology can provide precise positioning services and Precipitable Water Vapor (PWV) retrieval services for open seas in eastern China, remote areas in Asian countries, as well as regions where communication system destroyed by disasters. For the limited studies exploring the BDS-3 PPP-B2b performance of signal service and application in PWV retrieval, this paper used one-month observation data from 8 IGS MGEX stations in China and neighboring countries to analyze the service capability of the PPP-B2b signal. The results show that the B2b orbit product’s precision in radial (R), along (A), and cross (C) directions are better than 0.08, 0.25, and 0.30 m, respectively. The standard deviation (STD) of clock offsets is better than 0.23 ns. The accuracy of static PPP solutions is at the centimeter level, while it is at the decimeter level for the dynamic PPP solutions. The central stations have better results than those at the boundary of the service areas. For exploring the application of the PPP-B2b signal in the retrieval application service of PWV, the zenith tropospheric delay (ZTD) is estimated based on the PPP-B2b signal, which is highly consistent with the results from the WUM analysis center products. The accuracy of the root mean square (RMS) is 3.41mm and the STD is 2.84 mm for PWV retrieval products based on PPP-B2b, which compared with the post-production. The RMS for the boundary station is less than 4 mm, meeting the accuracy requirements. The experiments indicate that the PPP-B2b signal can provide precise positioning services for the service areas, where lack of communication, and provide more reliable data for applications such as real-time numerical weather prediction.