Localizability Analysis for GPS/Galileo Receiver Autonomous Integrity Monitoring

2004 ◽  
Vol 57 (2) ◽  
pp. 245-259 ◽  
Author(s):  
Steve Hewitson ◽  
Hung Kyu Lee ◽  
Jinling Wang
Keyword(s):  
Quality Measures ◽  
Integrity Monitoring ◽  
Satellite Navigation System ◽  
Detection And Identification ◽  
External Reference ◽  
Galileo System ◽  
Receiver Autonomous Integrity Monitoring ◽  
Navigation Signals ◽  
Gps System ◽  
Fundamental Equations

With the European Commission (EC) and European Space Agency's (ESA) plans to develop a new satellite navigation system, Galileo and the modernisation of GPS well underway the integrity of such systems is as much, if not more, of a concern as ever. Receiver Autonomous Integrity Monitoring (RAIM) refers to the integrity monitoring of the GPS/Galileo navigation signals autonomously performed by the receiver independent of any external reference systems, apart from the navigation signals themselves. Quality measures need to be used to evaluate the RAIM performance at different locations and under various navigation modes, such as GPS only and GPS/Galileo integration, etc. The quality measures should include both the reliability and localizability measures. Reliability is used to assess the capability of GPS/Galileo receivers to detect the outliers while localizability is used to determine the capability of GPS/Galileo receivers to correctly identify the detected outlier from the measurements processed.Within this paper, the fundamental equations required for effective outlier detection and identification algorithms are described together with the measures of reliability and localizability. Detailed simulations and analyses have been performed to assess the performances of GPS only and integrated GPS/Galileo navigation solutions with respect to reliability and localizability. Simulation results show that, in comparison with the GPS-only solution, the localizability of the integrated GPS/Galileo solution can be improved by up to 270%. The results also indicate an expectation of a considerable increase in the sensitivity to outliers and accuracy of their estimation with the augmentation of the Galileo system with the existing GPS system.

GNSS Receiver Autonomous Integrity Monitoring with a Dynamic Model

2007 ◽  
Vol 60 (2) ◽  
pp. 247-263 ◽  
Author(s):  
Steve Hewitson ◽  
Jinling Wang
Keyword(s):  
Kalman Filtering ◽  
Markov Models ◽  
Dynamic Modelling ◽  
The State ◽  
Dynamic Information ◽  
Integrity Monitoring ◽  
Gnss Receiver ◽  
Detection And Identification ◽  
Receiver Autonomous Integrity Monitoring ◽  
The Impact

Traditionally, GNSS receiver autonomous integrity monitoring (RAIM) has been based upon single epoch solutions. RAIM can be improved considerably when available dynamic information is fused together with the GNSS range measurements in a Kalman filter. However, while the Kalman filtering technique is widely accepted to provide optimal estimates for the navigation parameters of a dynamic platform, assuming the state and observation models are correct, it is still susceptible to unmodelled errors. Furthermore, significant deviations from the assumed models for dynamic systems may also occur. It is therefore necessary that the state estimation procedure is complemented with effective and reliable integrity measures capable of identifying both measurement and modelling errors. Within this paper, fundamental equations required for the effective detection and identification of outliers in a kinematic GNSS positioning and navigation system are described together with the reliability and separability measures. These quality measures are implemented using a Kalman filtering procedure formulated with Gauss-Markov models where the state estimates are derived from least squares principles. Detailed simulations and analyses have been performed to assess the impact of the dynamic information on GNSS RAIM with respect to outlier detection and identification, reliability and separability. The ability of the RAIM algorithms to detect and identify dynamic modelling errors is also investigated.

scholarly journals A Modified Range Consensus Algorithm Based on GA for Receiver Autonomous Integrity Monitoring

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jing Zhao ◽  
Chengdong Xu ◽  
Yimei Jian ◽  
Pengfei Zhang
Keyword(s):  
Considerable Increase ◽  
Consensus Algorithm ◽  
Identification Performance ◽  
Integrity Monitoring ◽  
Detection And Identification ◽  
Convergence Process ◽  
Mathematical Simulations ◽  
Fault Detection And Identification ◽  
Speed Up ◽  
Receiver Autonomous Integrity Monitoring

With the considerable increase of visible satellites for positioning, the fault detection and identification performance of Range Consensus (RANCO) algorithm for Receiver Autonomous Integrity Monitoring (RAIM) will significantly be improved. However, the calculation amount of RANCO algorithm will exponentially increase for the sharp addition of visible satellite subsets. This paper proposes a modified RANCO algorithm based on genetic algorithm (GA-RANCO) for RAIM to inhibit the exponentially expanded calculation amount. To reduce the calculation amount in searching the optimal minimal necessary subset (MNS), the preselection step is developed to speed up the convergence process of GA-RANCO. It is executed to exclude the chromosome-represented MNS for which the count of faulty satellites will exceed the upper limit of independent simultaneous satellite faults to be monitored. Mathematical simulations are introduced to determine the GA parameters, and simulation experiments under different schemes are designed to evaluate the performance of GA-RANCO algorithm. Results illustrate that the time consumption under a large number of visible satellites of GA-RANCO is much lower than that of RANCO and the faulty detection and identification performance of GA-RANCO is the same as that of RANCO.

scholarly journals Analyses of the sensitivity of multi-constellation advanced receiver autonomous integrity monitoring vertical protection level availability to error parameters and a failure model over China

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401877619 ◽  
Author(s):  
Xueen Zheng ◽  
Ye Liu ◽  
Guochao Fan ◽  
Jing Zhao ◽  
Chengdong Xu
Keyword(s):  
Satellite System ◽  
Protection Level ◽  
Integrity Monitoring ◽  
System Service ◽  
Service Stations ◽  
Receiver Autonomous Integrity Monitoring ◽  
Global Navigation Satellite ◽  
Range Error ◽  
Monitoring Algorithm ◽  
Advanced Receiver

The availability of advanced receiver autonomous integrity monitoring for vertical guidance down to altitudes of 200 ft (LPV-200) is discussed using real satellite orbit/ephemeris data collected at eight international global navigation satellite system service stations across China. Analyses were conducted for the availability of multi-constellation advanced receiver autonomous integrity monitoring and multi-fault advanced receiver autonomous integrity monitoring, and the sensitivity of availability in response to changes in error model parameters (i.e. user range accuracy, user range error, Bias-Nom and Bias-Max) was used to compute the vertical protection level. The results demonstrated that advanced receiver autonomous integrity monitoring availability based on multiple constellations met the requirements of LPV-200 despite multiple-fault detections that reduced the availability of the advanced receiver autonomous integrity monitoring algorithm; the advanced receiver autonomous integrity monitoring availability thresholds of the user range error and Bias-Nom used for accuracy were more relevant to geographic information than the user range accuracy and Bias-Max used for integrity at the eight international global navigation satellite system service stations. Finally, the possibility of using the advanced receiver autonomous integrity monitoring algorithm for a Category III navigation standard is discussed using two sets of predicted errors, revealing that the algorithm could be used in 79% of China.

An Advanced Receiver Autonomous Integrity Monitoring (ARAIM) Ground Monitor Design to Estimate Satellite Orbits and Clocks

2020 ◽  
Vol 73 (5) ◽  
pp. 1087-1105
Author(s):  
Yawei Zhai ◽  
Jaymin Patel ◽  
Xingqun Zhan ◽  
Mathieu Joerger ◽  
Boris Pervan
Keyword(s):  
Measurement Errors ◽  
Satellite Orbit ◽  
Global Navigation Satellite Systems ◽  
Estimation Accuracy ◽  
Satellite Orbits ◽  
Integrity Monitoring ◽  
Satellite Systems ◽  
Receiver Autonomous Integrity Monitoring ◽  
The Impact ◽  
Advanced Receiver

This paper describes a method to determine global navigation satellite systems (GNSS) satellite orbits and clocks for advanced receiver autonomous integrity monitoring (ARAIM). The orbit and clock estimates will be used as a reference truth to monitor signal-in-space integrity parameters of the ARAIM integrity support message (ISM). Unlike publicly available orbit and clock products, which aim to maximise estimation accuracy, a straightforward and transparent approach is employed to facilitate integrity evaluation. The proposed monitor is comprised of a worldwide network of sparsely distributed reference stations and will employ parametric satellite orbit models. Two separate analyses, covariance analysis and model fidelity evaluation, are carried out to assess the impact of measurement errors and orbit model uncertainty on the estimated orbits and clocks, respectively. The results indicate that a standard deviation of 30 cm can be achieved for the estimated orbit/clock error, which is adequate for ISM validation.

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