SPODS Software and Its Result of Precise Orbit Determination for GNSS Satellites

Ruan, Rengui; Jia, Xiaolin; Wu, Xun; Feng, Lihui; Zhu, Yanbo

doi:10.1007/978-3-642-54740-9_27

Cited by 14 publications

(4 citation statements)

References 11 publications

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“…The analysis centers process the observations collected by tracking stations to generate high-precision GNSS products and submit the products to ISC. Currently, twelve ACs contribute products to iGMAS ISC routinely: Beijing Aerospace Control Center (BAC) [24], Chinese Academy of Surveying and mapping (CGS), Chang'an University (CHD) [25], China University of Mining and Technology (CUM) [26], Institute of Geodesy and Geophysics (CGS), Information Engineering University (LSN) [27], National Time Service Center (NTS) [28], Shanghai Astronomical Observatory (SHA), Tongji University (TJU), Xi'an Research Institute of Surveying and Mapping (XRS) [27], Xi'an Satellite Control Center (XSC) [29], and Wuhan University (WHU) [30].…”

Section: Overview Of Igmas Iscmentioning

confidence: 99%

Multi-GNSS Combined Orbit and Clock Solutions at iGMAS

Zhou¹,

Cai²,

Chen

et al. 2022

Sensors

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Global navigation services from the quad-constellation of GPS, GLONASS, BDS, and Galileo are now available. The international GNSS monitoring and assessment system (iGMAS) aims to evaluate the navigation performance of the current quad systems under a unified framework. In order to assess impact of orbit and clock errors on the positioning accuracy, the user range error (URE) is always taken as a metric by comparison with the precise products. Compared with the solutions from a single analysis center, the combined solutions derived from multiple analysis centers are characterized with robustness and reliability and preferred to be used as references to assess the performance of broadcast ephemerides. In this paper, the combination method of iGMAS orbit and clock products is described, and the performance of the combined solutions is evaluated by various means. There are different internal precisions of the combined orbit and clock for different constellations, which indicates that consistent weights should be assigned for individual constellations and analysis centers included in the combination. For BDS-3, Galileo, and GLONASS combined orbits of iGMAS, the root-mean-square error (RMSE) of 5 cm is achieved by satellite laser ranging (SLR) observations. Meanwhile, the SLR residuals are characterized with a linear pattern with respect to the position of the sun, which indicates that the solar radiation pressure (SRP) model adopted in precise orbit determination needs further improvement. The consistency between combined orbit and clock of quad-constellation is validated by precise point positioning (PPP), and the accuracies of simulated kinematic tests are 1.4, 1.2, and 2.9 cm for east, north, and up components, respectively.

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Section: Overview Of Igmas Iscmentioning

confidence: 99%

Multi-GNSS Combined Orbit and Clock Solutions at iGMAS

Zhou¹,

Cai²,

Chen

et al. 2022

Sensors

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“…Then, the BDS-3 UC POD result is presented for the first time. This work was conducted based on the software of the satellite positioning and orbit determination system (SPODS) (Ruan et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Uncombined precise orbit and clock determination of GPS and BDS-3

et al. 2020

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There is increasing concern about the uncombined (UC) observation model in the field of global navigation satellite system (GNSS). Based on the global positioning system (GPS) and the third-generation BeiDou navigation satellite system (BDS-3), this study processed the UC precision orbit determination (POD) for single and dual systems. First, a UC observation model suitable for multi-GNSS POD was derived, and the ionospheric-free (IF) combination observation model was presented. Although the ambiguity parameters of UC and IF strategies were different after reparameterization, the difference could be removed when processing ambiguity resolution, and the equivalence was proved theoretically. To demonstrate the accuracy of BDS-3 orbits fully, the observation data of approximately 1 month were selected for determining the precise orbit for global positioning system (GPS) only, BDS-3 only, and GPS/BDS-3 systems based on the UC and IF models. The orbit precision of BDS-3 satellites was validated by using metrics, including comparison with precision products released by Wuhan University, orbit boundary discontinuity, and satellite laser ranging (SLR) residuals. The results show that the orbit accuracies of the IF and UC models are almost the same, the difference in orbits is approximately several millimeters, and the clock difference is within 0.01 ns. The GPS/BDS-3 combined solution shows better accuracy compared to other solutions. The average accuracies in the R and 3D directions are approximately 4 and 15 cm, and the clock standard deviation is approximately 0.2 ns compared to external orbit product. The root mean square of SLR residuals is approximately 4 cm.

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“…In order to validate that the XRS product is competent to evaluate space clock stability, the XRS product precision is first analyzed. The multi-GNSS XRS precise orbit and clock product is calculated by the software Satellite Positioning and Orbit Determination System (SPODS) [27]. About 80 MGEX stations and 20 iGMAS stations with GPS, BDS, Galileo, and GLONASS satellite data are used to process precise orbit determination, including ultrarapid (XRU), rapid (XRR), and final (XRS) products in the daily routine.…”

Section: Precise Orbit and Clock Product Introduction And Analysismentioning

confidence: 99%

“…First, methodology is introduced. The ODTS product from Xi'an Research Institute of Surveying and Mapping (XRS) [27] is introduced and compared to the Wuhan University product (WUM) and the IGS final product. Then, the ODTS noise is calculated by a few ground stations which are attached to the high-precision active hydrogen masers (AHM).…”

mentioning

confidence: 99%

Atomic Clock Performance Assessment of BeiDou-3 Basic System with the Noise Analysis of Orbit Determination and Time Synchronization

et al. 2019

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The basic system of the BeiDou global navigation satellite system (BDS-3) with 18 satellites has been deployed since December 2018. As the primary frequency standard, BDS-3 satellites include two clock types with the passive hydrogen maser (PHM) and the rubidium atomic frequency standard (RAFS). Based on the final precise orbit and clock product from Xi’an Research Institute of Surveying and Mapping (XRS), the atomic clock performance of BDS-3 satellites is evaluated, including the frequency accuracy, frequency drift rate, and frequency stability, and compared with GPS block IIF satellites with RAFS, Galileo satellites with PHM, and BDS-2 satellites. A data auto-editing procedure to preprocess clock data and assess the clock performance is developed, where the assessed results are derived at each continuous data arc and the outliers are excluded properly. The stability of XRS product noise is given by using some stations equipped with high-precision active hydrogen masers (AHM). The best stability is 8.93 × 10−15 and 1.85 × 10−15 for the averaging time of 10,000 s and 1 day, which is basically comparable to one-third of the in-orbit PHM frequency stability. The assessed results show the average frequency accuracy and drift rate of BDS-3 with RAFS are slightly worse while the stability is better than BDS-2 medium earth orbit (MEO) satellites. The 10,000 s stability is better but the 1-day stability is worse than GPS, which may be related to the performance of the BDS-3 RAFS clock. As for BDS-3 with PHM, the frequency accuracy is slightly worse than Galileo PHM satellites; the drift rate, when excluding C34 and C35, is basically comparable to Galileo and significantly better than GPS satellites; the stability is comparable to Galileo, where the 10,000 s stability is slightly worse than Galileo and better than GPS. The 1-day stability among BDS-3 PHM, GPS IIF RAFS, and Galileo PHM satellites is basically comparable.

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SPODS Software and Its Result of Precise Orbit Determination for GNSS Satellites

Cited by 14 publications

References 11 publications

Multi-GNSS Combined Orbit and Clock Solutions at iGMAS

Multi-GNSS Combined Orbit and Clock Solutions at iGMAS

Uncombined precise orbit and clock determination of GPS and BDS-3

Atomic Clock Performance Assessment of BeiDou-3 Basic System with the Noise Analysis of Orbit Determination and Time Synchronization

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