Precise Point Positioning Performance Evaluation of QZSS Centimeter Level Augmentation Service

摘要

The Japanese Quasi-Zenith Satellite System (QZSS) provides Centimeter-Level Augmentation Service (CLAS) through L6 signal. The L6 augmentation messages includes satellite orbit correction, clock correction, phase bias, code bias, troposphere correction, ionosphere correction and other augmentation messages. These augmentation messages are used for a PPP-RTK service. Using PPP-RTK service, users in Japan can get high-precision real-time positioning results. Based on the measured data of AIRA, STK2, TSK2 and USUD of four MGEX stations in Japan, this paper analyzes the PPP augmentation performance of L6 augmentation signal by post static PPP, and compares it with the calculation results of QZSS final orbit and clock products. The results show that there is still a certain gap between the accuracy of orbit and clock augmented by L6 signal and the final products of QZSS. The static PPP based on L6 signal can realize centimeter-decimeter level positioning, and the positioning accuracy is lower than that of the final products of QZSS. Analysis reason: as CLAS are used to augment PPP-RTK services, PPP augmented service is out of scope of its pre-service. Therefore, the published orbit and clock correction are not a real-time precise orbit and clock correction, which leads to a gap between the corrected orbit and clock and the final products. Similarly, due to different application services, there are differences in positioning results.