scholarly journals Performance assessment of GNSS-based real-time navigation for the Sentinel-6 spacecraft

GPS Solutions ◽  
2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Oliver Montenbruck ◽  
Florian Kunzi ◽  
André Hauschild
Keyword(s):  
Real Time ◽  
Orbit Determination ◽  
Low Earth Orbit ◽  
Gps Tracking ◽  
Force Model ◽  
Dynamic Force ◽  
Phase Measurements ◽  
Satellite Navigation System ◽  
Offline Processing ◽  
L2c Signal

AbstractThe feasibility of precise real-time orbit determination of low earth orbit satellites using onboard GNSS observations is assessed using six months of flight data from the Sentinel-6A mission. Based on offline processing of dual-constellation pseudorange and carrier phase measurements as well as broadcast ephemerides in a sequential filter with a reduced dynamic force model, navigation solutions with a representative position error of 10 cm (3D RMS) are achieved. The overall performance is largely enabled by the superior quality of the Galileo broadcast ephemerides, which exhibits a two- to three-times smaller signal-in-space-range error than GPS and allows for geodetic-grade GNSS real-time orbit determination without a need for external correction services. Compared to GPS-only processing, a roughly two-times better navigation accuracy is achieved in a Galileo-only or mixed GPS/Galileo processing. On the other hand, GPS tracking offers a useful complement and additional robustness in view of a still incomplete Galileo constellation. Furthermore, it provides improved autonomy of the navigation process through the availability of earth orientation parameters in the new civil navigation message of the L2C signal. Overall, GNSS-based onboard orbit determination can now reach a similar performance as the DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) navigation system. It lends itself as a viable alternative for future remote sensing missions.

Real-time orbit determination of Low Earth orbit satellite based on RINEX/DORIS 3.0 phase data and spaceborne GPS data

2020 ◽  
Vol 66 (7) ◽  
pp. 1700-1712
Author(s):  
Chongchong Zhou ◽  
Shiming Zhong ◽  
Bibo Peng ◽  
Jikun Ou ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Orbit Determination ◽  
Low Earth Orbit ◽  
Gps Data ◽  
Earth Orbit ◽  
Orbit Satellite ◽  
Low Earth Orbit Satellite ◽  
Phase Data

scholarly journals Real Time On-board Orbit Determination Performance Analysis of Low Earth Orbit Satellites

2015 ◽  
Vol 43 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Eun-Hyouek Kim ◽  
Dong-Wook Koh ◽  
Young-Suk Chung ◽  
Sung-Baek Park ◽  
Hyeun-Pil Jin ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Real Time ◽  
Orbit Determination ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Low Earth Orbit Satellites

Comparison of precise orbit determination methods of zero-difference kinematic, dynamic and reduced-dynamic of GRACE-A satellite using SHORDE software

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Kai Li ◽  
Xuhua Zhou ◽  
Nannan Guo ◽  
Gang Zhao ◽  
Kexin Xu ◽  
...  
Keyword(s):  
Orbit Determination ◽  
Precise Orbit Determination ◽  
Low Earth Orbit ◽  
Phase Measurements ◽  
Perturbation Model ◽  
Precise Orbit ◽  
Average Accuracy ◽  
Low Earth Orbit Satellites ◽  
Gps Observations ◽  
Reduced Dynamic

AbstractZero-difference kinematic, dynamic and reduced-dynamic precise orbit determination (POD) are three methods to obtain the precise orbits of Low Earth Orbit satellites (LEOs) by using the on-board GPS observations. Comparing the differences between those methods have great significance to establish the mathematical model and is usefull for us to select a suitable method to determine the orbit of the satellite. Based on the zero-difference GPS carrier-phase measurements, Shanghai Astronomical Observatory (SHAO) has improved the early version of SHORDE and then developed it as an integrated software system, which can perform the POD of LEOs by using the above three methods. In order to introduce the function of the software, we take the Gravity Recovery And Climate Experiment (GRACE) on-board GPS observations in January 2008 as example, then we compute the corresponding orbits of GRACE by using the SHORDE software. In order to evaluate the accuracy, we compare the orbits with the precise orbits provided by Jet Propulsion Laboratory (JPL). The results show that: (1) If we use the dynamic POD method, and the force models are used to represent the non-conservative forces, the average accuracy of the GRACE orbit is 2.40cm, 3.91cm, 2.34cm and 5.17cm in radial (R), along-track (T), cross-track (N) and 3D directions respectively; If we use the accelerometer observation instead of non-conservative perturbation model, the average accuracy of the orbit is 1.82cm, 2.51cm, 3.48cm and 4.68cm in R, T, N and 3D directions respectively. The result shows that if we use accelerometer observation instead of the non-conservative perturbation model, the accuracy of orbit is better. (2) When we use the reduced-dynamic POD method to get the orbits, the average accuracy of the orbit is 0.80cm, 1.36cm, 2.38cm and 2.87cm in R, T, N and 3D directions respectively. This method is carried out by setting up the pseudo-stochastic pulses to absorb the errors of atmospheric drag and other perturbations. (3) If we use the kinematic POD method, the accuracy of the GRACE orbit is 2.92cm, 2.48cm, 2.76cm and 4.75cm in R, T, N and 3D directions respectively. In conclusion, it can be seen that the POD of GRACE satellite is practicable by using different strategies and methods. The orbit solution is well and stable, they all can obtain the GRACE orbits with centimeter-level precision.

scholarly journals Real-Time Precise Orbit Determination for LEO between Kinematic and Reduced-Dynamic with Ambiguity Resolution

Aerospace ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 25
Author(s):  
Zhiyu Wang ◽  
Zishen Li ◽  
Ningbo Wang ◽  
Mainul Hoque ◽  
Liang Wang ◽  
...  
Keyword(s):  
Real Time ◽  
Ambiguity Resolution ◽  
Orbit Determination ◽  
Fixed Ratio ◽  
Precise Orbit Determination ◽  
Low Earth Orbit ◽  
Integer Ambiguity ◽  
The Real ◽  
Precise Orbit ◽  
Reduced Dynamic

The real-time integer-ambiguity resolution of the carrier-phase observation is one of the most effective approaches to enhance the accuracy of real-time precise point positioning (PPP), kinematic precise orbit determination (KPOD), and reduced-dynamic precise orbit determination (RPOD) for low earth orbit (LEO) satellites. In this study, the integer phase clock (IPC) and wide-lane satellite bias (WSB) products from CNES (Centre National d’Etudes Spatiales) are used to fix ambiguity in real time. Meanwhile, the three models of real-time PPP, KPOD, and RPOD are applied to validate the contribution of ambiguity resolution. Experimental results show that (1) the average positioning accuracy of IGS stations for ambiguity-fixed solutions is improved from about 7.14 to 5.91 cm, with an improvement of around 17% compared to the real-time float PPP solutions, with enhancement in the east-west direction particularly significant, with an improvement of about 29%; (2) the average accuracy of the estimated LEO orbit with ambiguity-fixed solutions in the real-time KPOD and RPOD mode is improved by about 16% and 10%, respectively, with respect to the corresponding mode with the ambiguity-float solutions; (3) the performance of real-time LEO RPOD is better than that of the corresponding KPOD, regardless of fixed- or float-ambiguity solutions. Moreover, the average ambiguity-fixed ratio can reach more than 90% in real-time PPP, KPOD, and RPOD.

scholarly journals Sensitivity of the Gravity Model and Orbital Frame for On-board Real-Time Orbit Determination: Operational Results of GPS-12 GPS Receiver

2019 ◽  
Vol 11 (13) ◽  
pp. 1542
Author(s):  
Eunhyouek Kim ◽  
Seungyeop Han ◽  
Amer Mohammad Al Sayegh
Keyword(s):  
Real Time ◽  
Gravity Model ◽  
Orbit Determination ◽  
Low Earth Orbit ◽  
Observation Data ◽  
Gps Receiver ◽  
Champ Satellite ◽  
Earth Gravity ◽  
Earth Gravity Model ◽  
Gravity Recovery

This paper describes the sensitivity of both the orbital frame domain selection and the gravity model on the performance of on-board real-time orbit determination. Practical error sources, which affect the navigation solution of spaceborne global positioning system (GPS) receivers, are analyzed first. Then, a reasonable orbital frame (radial, in-track, cross-track (RIC)) is proposed to clearly represent the characteristics of the error in order to improve the performance of the orbit determination (OD) logic. In addition, the sensitivity of the gravity model affecting the orbit determination logic is analyzed by comparison with the precise orbit ephemeris (POE) of the Challenging Minisatellite Payload (CHAMP) satellite, and it is confirmed that the Gravity Recovery And Climate Experiment (GRACE) Gravity Model 03 (GGM03) outperforms the Earth Gravity Model 1996 (EGM96). The effects of both proposed orbit frames and the gravity model on the orbit determination logic are verified using a GPS simulator and observation data from the CHAMP satellite. Moreover, the practical performance of on-board real-time orbit determination logic is verified by updating the software of the spaceborne GPS receiver, GPS-12, on DubaiSat-2 operating at low Earth orbit (LEO). The results show that the position accuracy of on-board real-time orbit determination logic in GPS-12 is improved by 59%, from 12.6 m (1 σ) to 5.1 m (1 σ), after applying the proposed methods. The velocity accuracy is also improved by 57%, from 13.7 mm/s (1 σ) to 5.9 mm/s (1 σ).

scholarly journals Centimeter-Level Orbit Determination for TG02 Spacelab Using Onboard GNSS Data

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2671 ◽  
Author(s):  
Kai Li ◽  
Xuhua Zhou ◽  
Wenbin Wang ◽  
Yang Gao ◽  
Gang Zhao ◽  
...  
Keyword(s):  
Orbit Determination ◽  
Dynamic Method ◽  
Precise Orbit Determination ◽  
Low Earth Orbit ◽  
Dual Frequency ◽  
Phase Measurements ◽  
Gnss Data ◽  
Cross Track ◽  
Along Track ◽  
Reduced Dynamic

Tiangong-2, the second Chinese manned spacecraft, was launched into low Earth orbit on 15 September 2016. The dual-frequency geodetic GNSS receiver equipped on it is supporting a number of scientific experiments in orbit. This paper uses the onboard GNSS data from 3–31 December 2016 (in the attitude mode of three-axis Earth-pointing stabilization) to analyze the data quantity, as well as the code multipath error. Then, the dynamic and reduced-dynamic methods are adopted to perform the post Precise Orbit Determination (POD) based on the carrier phase measurements, respectively. After that, the orbit accuracy is evaluated using a number of tests, which include the analysis of observation residuals, Overlapping Orbit Differences (OODs), orbit comparison between dynamic and reduced-dynamic and Satellite Laser Ranging (SLR) validation. The results show that: (1) the average Root Mean Square (RMS) of the on-board GNSS phase fitting residuals is 8.8 mm; (2) regarding the OODs determined by the reduced-dynamic method, the average RMS in radial (R), along-track (T) and cross-track (N) directions is 0.43 cm, 1.34 cm and 0.39 cm, respectively, and there are no obvious system errors; (3) the orbit accuracy of TG02 determined by the reduced-dynamic method is comparable to that of the dynamic method, and the average RMS of their differences in R, T, N and 3D directions is 3.05 cm, 3.60 cm, 2.52 cm and 5.40 cm, respectively; (4) SLR data are used to validate the reduced-dynamic orbits, and the average RMS along the station-satellite direction is 1.94 cm. It can be seen that both of these two methods can meet the demands of 3D centimeter-level orbit determination for TG02.

scholarly journals Onboard and Real-Time Artificial Satellite Orbit Determination Using GPS

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ana Paula Marins Chiaradia ◽  
Hélio Koiti Kuga ◽  
Antonio Fernando Bertachini de Almeida Prado
Keyword(s):  
Real Time ◽  
Orbit Determination ◽  
Artificial Satellite ◽  
Time Estimation ◽  
Satellite Orbit ◽  
Estimation Algorithm ◽  
Measurement Model ◽  
Integration Scheme ◽  
Force Model ◽  
Step Size

An algorithm for real-time and onboard orbit determination applying the Extended Kalman Filter (EKF) method is developed. Aiming at a very simple and still fairly accurate orbit determination, an analysis is performed to ascertain an adequacy of modeling complexity versus accuracy. The minimum set of to-be-estimated states to reach the level of accuracy of tens of meters is found to have at least the position, velocity, and user clock offset components. The dynamical model is assessed through several tests, covering force model, numerical integration scheme and step size, and simplified variational equations. The measurement model includes only relevant effects to the order of meters. The EKF method is chosen to be the simplest real-time estimation algorithm with adequate tuning of its parameters. In the developed procedure, the obtained position and velocity errors along a day vary from 15 to 20 m and from 0.014 to 0.018 m/s, respectively, with standard deviation from 6 to 10 m and from 0.006 to 0.008 m/s, respectively, with the SA either on or off. The results, as well as analysis of the final adopted models used, are presented in this work.

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