Single-station-augmented PPP-B2b considering the satellite-specific clock bias via short-message communication

Abstract

BeiDou Global Navigation Satellite System (BDS-3) PPP-B2b service greatly promotes the real-time precise point positioning applications. However, previous research works have revealed that a nonnegligible satellite-specific clock bias (SCB) exists in the PPP-B2b clock offset, causing the degradation of PPP-B2b positioning performance. In this paper, a single-station-augmented PPP-B2b considering the SCB via BDS-3 short-message communication (SMC) is proposed. Specifically, an easy-to-implement real-time extraction method of single-differenced (SD) SCB is proposed using a single reference station. Then, based on the extracted SCB augmentation information, a new full-rank estimable SCB-weighted model is proposed to enhance the PPP-B2b positioning. In addition, to effectively transmit the SCB augmentation information without regard to Internet, a delicate design of encoding and broadcast strategy is developed via the BDS-3 SMC function. The results show that the extracted SD SCB series of each satellite is highly stable over a certain period of observation arc. The precision of extracted SD SCB series of each satellite varies from 0.11 to 0.28 ns with a mean value of 0.18 ns. In addition, compared with the traditional PPP-B2b model, the proposed SCB-weighted model improves the positioning performance in the static and kinematic applications. Specifically, for the static application, the positioning accuracy of SCB-weighted model exhibits 35.3%, 66.7%, and 48.2% improvements in east, north, and up directions, respectively; the convergence time exhibits a 39.7% improvement. For the kinematic vehicle application, the SCB-weighted model exhibits a faster re-convergence speed. The positioning accuracy is improved from 0.421 to 0.208 m with a 50.6% improvement. In conclusion, the proposed single-station-augmented PPP-B2b using the SCB-weighted model is highly appreciated for enhancing the PPP-B2b positioning performance.