4:00 PM - 4:15 PM
[SGD01-08] Evaluation of Precise GNSS Orbits and Clocks Estimated by MADOCA
Keywords:GNSS, MADOCA, Orbit Determination
The Geospatial Information Authority of Japan (GSI) operates over 1,300 CORS (Continuously Operating Reference Stations) in Japan. Information of daily CORS position is essential for connecting the current position to the survey results. In recent years, daily CORS position has also been used as the basis for real-time high-precision positioning services, such as the Centimeter Level Augmentation Service (CLAS).
Japan's Quasi-Zenith Satellite System (QZSS), the first launch was in 2010, will have seven satellites and full operation by the end of FY2023. It will not only complement GPS to improve positioning accuracy in Japan, but also complete domestic satellite operations. However, the IGS does not release precise orbit and clock for the QZSS in official.
GSI, in cooperation with the Japan Aerospace Exploration Agency (JAXA), is currently estimating precise orbit and clock of GNSS satellites using the JAXA-developed MADOCA software, and is having to join the IGS Analysis Center. Since the IGS products is combined with the products estimated by each Analysis Center, if the products estimated by MADOCA will be used to combine IGS products, the MADOCA-derived products will be consistent with the IGS products, and the QZSS orbits will be equivalent to the IGS products.
GSI estimated the precise orbit from 1994 to the present by using MADOCA. The reference frame is IGS Repro3, and we compare MADOCA products with the IGS products for evaluation. The products of each Analysis Center were also compared in the same way. As a result, the precise orbit estimation of GPS satellites was comparable to that of each Analysis Center, while the accuracy of GLONASS satellites was slightly worse than that of each AC, which is a future issue.
Japan's Quasi-Zenith Satellite System (QZSS), the first launch was in 2010, will have seven satellites and full operation by the end of FY2023. It will not only complement GPS to improve positioning accuracy in Japan, but also complete domestic satellite operations. However, the IGS does not release precise orbit and clock for the QZSS in official.
GSI, in cooperation with the Japan Aerospace Exploration Agency (JAXA), is currently estimating precise orbit and clock of GNSS satellites using the JAXA-developed MADOCA software, and is having to join the IGS Analysis Center. Since the IGS products is combined with the products estimated by each Analysis Center, if the products estimated by MADOCA will be used to combine IGS products, the MADOCA-derived products will be consistent with the IGS products, and the QZSS orbits will be equivalent to the IGS products.
GSI estimated the precise orbit from 1994 to the present by using MADOCA. The reference frame is IGS Repro3, and we compare MADOCA products with the IGS products for evaluation. The products of each Analysis Center were also compared in the same way. As a result, the precise orbit estimation of GPS satellites was comparable to that of each Analysis Center, while the accuracy of GLONASS satellites was slightly worse than that of each AC, which is a future issue.