Improved Integration Method of Wide-area RTK/PPP with IMU and Odometer

Nobuaki Kubo, Daisuke Hatta, Kaito Kobayashi, Kyohei Aoki

Abstract: The Quasi-Zenith Satellite System (QZSS), Japanese positioning satellite constellation has two types of precise point positioning (PPP) services: centimeter-level augmentation service (CLAS) for land and multi-GNSS advanced demonstration tool for orbit and clock analysis (MADOCA). Currently, both CLAS and PPP correction data are broadcasted through the QZSS. It is highly good time to evaluate CLAS and PPP service in Japan. CLAS service has advantage in convergence time compared with PPP service. In the case of short gap like as overpasses, the convergence time is within 1 minute. The motivation of this research is to investigate the integration of CLAS or PPP results and our previous integration method using low-cost IMU/Odometer sensors. In reality, several commercial receivers capable of using CLAS or PPP correction services are already released in Japan. We used outputs of these receivers for absolute positions and loosely-coupled integration using Kalman filter is used to integrate them. The test data were obtained on the sea and expressway in 2019. Firstly, the performance of PPP and CLAS on the sea using the commercial receiver was evaluated. For the reference of these positions, normal RTK was obtained in parallel in this test on the sea. In the test on the expressway, POLSV was used in parallel to produce the precise positions as a reference. Looking at the test results on the sea, the fix rate of CLAS was from 63 % to 94. The standard deviation in horizontal was within 10 cm. On the other hand, the result of PPP was slightly worse than the result of CLAS. We didn’t evaluate the integrated navigation on the sea because it was impossible for us to obtain the speed information from the ship for now. Looking at the test results on the expressway, the fix rate of CLAS was also good over 70 %. The navigation performance of this integrated system was analyzed. The horizontal accuracy including some GNSS outages was stable and the standard deviation of all horizontal errors was 0.35 m. The 99 percentile value for the absolute horizontal errors was 1.34 m. 99.57 % of all solutions were less than 1.5 m. With regard to the test results of PPP and integrated system on the expressway, the results were introduced in Pacific ION 2019.
Published in: Proceedings of the 2020 International Technical Meeting of The Institute of Navigation
January 21 - 24, 2020
Hyatt Regency Mission Bay
San Diego, California
Pages: 772 - 786
Cite this article: Kubo, Nobuaki, Hatta, Daisuke, Kobayashi, Kaito, Aoki, Kyohei, "Improved Integration Method of Wide-area RTK/PPP with IMU and Odometer," Proceedings of the 2020 International Technical Meeting of The Institute of Navigation, San Diego, California, January 2020, pp. 772-786.
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