RTKLIB-B2b: open-source real-time decoding module for BDS-3 PPP-B2b in RTKLIB

The BeiDou Navigation Satellite System (BDS) offers precise point positioning (PPP) corrections via its public PPP-B2b service. However, the use of proprietary binary output formats by receiver manufacturers and the lack of corresponding open-source C/C++ decoding tools hinder the integration of these corrections into common processing workflows like RTKLIB. To overcome this limitation, we developed RTKLIB-B2b, an open-source toolkit built with C/C++ that extends the functionalities of RTKLIB. RTKLIB-B2b is specifically designed to decode proprietary binary PPP-B2b correction streams and associated navigation messages, including the global positioning system legacy navigation message and the BDS B1C signal NAV message (B-CNAV1), from prevalent ComNav Technology (ComNav) and Unicore Communications (Unicore) receivers. It supports both real-time and post-processing scenarios, integrates the decoded corrections for PPP, and outputs the corrections in an extended, BKG networked transport of RTCM via internet protocol client-compatible ASCII format. Validation experiments, using both real-time streams from global navigation satellite system (GNSS) receivers and GNSS observation files from International GNSS Service stations, confirmed RTKLIB-B2b’s capability to successfully decode and utilize PPP-B2b corrections, enabling decimeter-level PPP. The RTKLIB-B2b software provides an open-source C/C++ tool poised to facilitate the broader utilization of the PPP-B2b service within the GNSS research and application domains.