Convergence Time Analysis of Multi-constellation Precise Point Positioning Based on iGMAS Products

Ge, Yulong; Sun, Binyong; Wang, Shengli; Shen, Pengli; Liu, Jinhai

doi:10.1007/978-981-10-0940-2_26

Cited by 5 publications

(3 citation statements)

References 4 publications

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“…The positioning accuracy of multi-constellation PPP shows better performance than single constellation PPP. Compared with single constellation PPP, Multi-constellation PPP can obviously improve the convergence time [32]. The BDS-only PPP has poorer accuracy than the GPS-only PPP.…”

Section: Experimental Results and Analysismentioning

confidence: 99%

The Impact of Satellite Time Group Delay and Inter-Frequency Differential Code Bias Corrections on Multi-GNSS Combined Positioning

Zhou

Sun

et al. 2017

Sensors

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We present quad-constellation (namely, GPS, GLONASS, BeiDou and Galileo) time group delay (TGD) and differential code bias (DCB) correction models to fully exploit the code observations of all the four global navigation satellite systems (GNSSs) for navigation and positioning. The relationship between TGDs and DCBs for multi-GNSS is clearly figured out, and the equivalence of TGD and DCB correction models combining theory with practice is demonstrated. Meanwhile, the TGD/DCB correction models have been extended to various standard point positioning (SPP) and precise point positioning (PPP) scenarios in a multi-GNSS and multi-frequency context. To evaluate the effectiveness and practicability of broadcast TGDs in the navigation message and DCBs provided by the Multi-GNSS Experiment (MGEX), both single-frequency GNSS ionosphere-corrected SPP and dual-frequency GNSS ionosphere-free SPP/PPP tests are carried out with quad-constellation signals. Furthermore, the author investigates the influence of differential code biases on GNSS positioning estimates. The experiments show that multi-constellation combination SPP performs better after DCB/TGD correction, for example, for GPS-only b1-based SPP, the positioning accuracies can be improved by 25.0%, 30.6% and 26.7%, respectively, in the N, E, and U components, after the differential code biases correction, while GPS/GLONASS/BDS b1-based SPP can be improved by 16.1%, 26.1% and 9.9%. For GPS/BDS/Galileo the 3rd frequency based SPP, the positioning accuracies are improved by 2.0%, 2.0% and 0.4%, respectively, in the N, E, and U components, after Galileo satellites DCB correction. The accuracy of Galileo-only b1-based SPP are improved about 48.6%, 34.7% and 40.6% with DCB correction, respectively, in the N, E, and U components. The estimates of multi-constellation PPP are subject to different degrees of influence. For multi-constellation combination SPP, the accuracy of single-frequency is slightly better than that of dual-frequency combinations. Dual-frequency combinations are more sensitive to the differential code biases, especially for the 2nd and 3rd frequency combination, such as for GPS/BDS SPP, accuracy improvements of 60.9%, 26.5% and 58.8% in the three coordinate components is achieved after DCB parameters correction. For multi-constellation PPP, the convergence time can be reduced significantly with differential code biases correction. And the accuracy of positioning is slightly better with TGD/DCB correction.

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Section: Experimental Results and Analysismentioning

confidence: 99%

The Impact of Satellite Time Group Delay and Inter-Frequency Differential Code Bias Corrections on Multi-GNSS Combined Positioning

Zhou

Sun

et al. 2017

Sensors

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“…The IF pseudorange and carrier phase observation equations can be written as follows [ 24 ]:

where r and s indicate the receiver and satellite, respectively; Φ is the carrier phase observations; λ IF indicates the wavelength of the carrier phase;

is the unit vector from the receiver to the satellite; δ X r is the vector of the coordinate increments; B r,IF and

represent receiver and satellite uncalibrated code delays (UCDs); c is the speed of light; δ t r,IF is the receiver clock offset; δt s denotes the satellite clock offset; b r,IF and

indicate the receiver and satellite uncalibrated phase delays (UPDs); N IF denotes integer ambiguity; M w indicates the wet mapping function; T w refers to the tropospheric zenith wet delay (ZWD). Note that the B1I/B3I IF combination was employed to analyse PPP performance.…”

Section: Methodsmentioning

confidence: 99%

An Investigation of Precise Orbit and Clock Products for BDS-3 from Different Analysis Centers

Shen

Fang

et al. 2021

Sensors

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A quality evaluation of precise products for BDS-3 constellations is presented for the first time in this contribution. Then, the tropospheric delay retrieval and positioning performance of BDS-3 precise point positioning (PPP) solutions using the precise products (gbm, wum, iac, sha, cnt) with observations from 24 stations from DOY 280 to 317 in 2020 was comprehensively investigated. The orbit comparisons present consistencies of 0.09–0.22 m for the C19–C37 satellites and of 0.5–1.2 m for the C38–C46 satellites among the final products. The standard deviation (STD) values of the clock differences of iac showed the best agreement with those of gbm, followed by wum, sha. The clock differences performance of cnt was the worst. For BDS-3 PPP solutions with five Analysis centers (ACs) products, the median convergence times of static PPP mode incorporating the gbm, wum, iac, sha, and cnt products were 31.0, 33.5, 34.5, 37.8, and 72.0 min, respectively; the median convergence times of kinematic PPP model incorporating the same products were 40.5, 41.0, 50.5, 55.0, and 94.0 min, respectively. The positioning accuracies in the static and kinematic modes were approximately 1–4 cm, 2–6 cm in the horizontal and vertical components, respectively. With the final products in kinematic mode, the performance of PPP with real-time products (cnt) is poorer than all PPP with final products. The median of ZTD accuracies of the five products gbm, wum, iac, sha, and cnt were 7.84, 7.58, 7.04, 7.19, and 10.1 mm, respectively, and the accuracy differences were very small among five AC products (gbm, wum, iac, sha).

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“…To achieve services with various levels of precision, GNSS products with a specific precision are indispensable, and orbit, clock offset, and tropospheric delay services rely on such data. The International GNSS Service (IGS) and the International GNSS Monitoring and Assessment System have been providing products for many years [5][6][7]. In particular, satellite orbit information is the fundamental requirement of these products and is used to ensure that spacecraft can operate normally [8].…”

Section: Introductionmentioning

confidence: 99%

Analysis and improvement of the Bancroft algorithm for GNSS satellite orbit determination

Chen¹,

Sheng²,

Yi³

et al. 2022

Meas. Sci. Technol.

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Satellite orbit information is crucial for ensuring that global navigation satellite systems (GNSSs) provide appropriate positioning, navigation and timing services. Typically, users can obtain access to orbit information of a specific accuracy level from navigation messages or precise ephemeris products. Without this information, a system will not be able to provide normal service. In response to this problem, initial orbit information of a certain level of precision must be obtained to support subsequent applications, such as broadcasting or precise ephemeris calculations, thereby ensuring the successful subsequent operation of the navigation system. One of two ways to calculate the initial orbit of a GNSS satellite is to utilize ground tracking stations to observe satellite vector information in the geocentric inertial system; the second way is to utilize GNSS range observations and known orbit information from other satellites. For the second approach, some researchers use the Bancroft algorithm combined with receiver clock offset to determine the initial orbit of GNSS satellites. Because this method requires an additional known receiver clock offset, we study the dependence of the Bancroft algorithm on clock offset in GNSS orbit determination. By assessing the impact of errors of different magnitude on the accuracy of the orbit results, we obtain experimental conclusions. After comprehensively analyzing various errors, we determine the accuracy level that the Bancroft algorithm can achieve for orbit determination without considering receiver clock correction. Dual-frequency and single-frequency pseudorange data from IGS stations are used in orbit determination experiments. When a small receiver clock offset is considered and no correction is made, the deviations in the calculated satellite positions in three dimensions are approximately 979.3 and 1118.1 meters (dual and single frequency); with a satellite clock offset, these values are approximately 928.8 and 1062.7 meters (dual and single frequency).

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Convergence Time Analysis of Multi-constellation Precise Point Positioning Based on iGMAS Products

Cited by 5 publications

References 4 publications

The Impact of Satellite Time Group Delay and Inter-Frequency Differential Code Bias Corrections on Multi-GNSS Combined Positioning

The Impact of Satellite Time Group Delay and Inter-Frequency Differential Code Bias Corrections on Multi-GNSS Combined Positioning

An Investigation of Precise Orbit and Clock Products for BDS-3 from Different Analysis Centers

Analysis and improvement of the Bancroft algorithm for GNSS satellite orbit determination

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