Carrier-Phase Acceleration RAIM for GNSS Satellite Clock Fault Detection

Navigation ◽  
2012 ◽  
Vol 59 (3) ◽  
pp. 221-235 ◽  
Author(s):  
Okuary Osechas ◽  
Pratap Misra ◽  
Jason Rife
Keyword(s):  
Fault Detection ◽  
Carrier Phase ◽  
Satellite Clock ◽  
Phase Acceleration

scholarly journals Covariance Analysis of Real-Time Precise GPS Orbit Estimated from Double-Differenced Carrier Phase Observations

2019 ◽  
Vol 11 (19) ◽  
pp. 2271 ◽  
Author(s):  
Sunkyoung Yu ◽  
Donguk Kim ◽  
Junesol Song ◽  
Changdon Kee
Keyword(s):  
Fault Detection ◽  
Real Time ◽  
Global Positioning System ◽  
Carrier Phase ◽  
Satellite System ◽  
Additional Parameter ◽  
Global Positioning ◽  
Correlation Information ◽  
Global Navigation Satellite ◽  
Orbit Errors

The covariance of real-time global positioning system (GPS) orbits has been drawing attention in various fields such as user integrity, navigation performance improvement, and fault detection. The international global navigation satellite system (GNSS) service (IGS) provides real-time orbit standard deviations without correlations between the axes. However, without correlation information, the provided covariance cannot assure the performance of the orbit product, which would, in turn, causes significant problems in fault detection and user integrity. Therefore, we studied real-time GPS orbit covariance characteristics along various coordinates to effectively provide conservative covariance. To this end, the covariance and precise orbits are estimated by means of an extended Kalman filter using double-differenced carrier phase observations of 61 IGS reference stations. Furthermore, we propose a new method for providing covariance to minimize loss of correlation. The method adopted by the IGS, which neglects correlation, requires 4.5 times the size of the covariance to bind orbit errors. By comparison, our proposed method reduces this size from 4.5 to 1.3 using only one additional parameter. In conclusion, the proposed method effectively provides covariance to users.

Carrier Phase Relative RAIM Algorithms and Protection Level Derivation

2010 ◽  
Vol 63 (2) ◽  
pp. 215-231 ◽  
Author(s):  
Livio Gratton ◽  
Mathieu Joerger ◽  
Boris Pervan
Keyword(s):  
Fault Detection ◽  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Resolution Time ◽  
Protection Level ◽  
Integrity Monitoring ◽  
Phase Measurements ◽  
Aircraft Navigation ◽  
Time Differential ◽  
Receiver Autonomous Integrity Monitoring

The concept of Relative Receiver Autonomous Integrity Monitoring (RRAIM) using time differential carrier phase measurements is investigated in this paper. The precision of carrier phase measurements allows for mitigation of integrity hazards by implementing RRAIM monitors with tight thresholds without significantly affecting continuity. In order to avoid the need for cycle ambiguity resolution, time differences in carrier phase measurements are used as the basis for detection. In this work, we examine RRAIM within the context of the GNSS Evolutionary Architecture Study (GEAS), which explores potential architectures for aircraft navigation utilizing the satellite signals available in the mid-term future with GPS III. The objectives of the GEAS are focused on system implementations providing worldwide coverage to satisfy LPV-200 operations, and potentially beyond. In this work, we study two different GEAS implementations of RRAIM. General formulas are derived for positioning, fault detection, and protection level generation to meet a given set of integrity and continuity requirements.

Real-Time GPS Clock Monitoring with IGS Ultra-Rapid Products

2011 ◽  
Vol 301-303 ◽  
pp. 1293-1298
Author(s):  
Youn Jeong Heo ◽  
Jeongho Cho ◽  
Moon Beom Heo
Keyword(s):  
Real Time ◽  
Carrier Phase ◽  
Time Transfer ◽  
Satellite Clock ◽  
Short Term ◽  
Transfer Method ◽  
The Stability

The objective of this study is to develop a real-time strategy that results in higher precision than any real-time solutions currently available for GPS satellite clock monitoring. A real-time time transfer methodology was employed for satellite clock monitoring, composed of carrier phase smoothed code measurements and IGS ultra-rapid products to obtain precise satellite positions. The performance of the time transfer method was assessed by comparison with the results based on the all-in-view method using the broadcasting ephemeredes. The results showed that the stability of satellite clock monitoring for a short-term period was improved by the proposed method.

An Optimizing Evaluation of Estimation Algorithm about the Fault Detection and Exclusion in the WAAS

2013 ◽  
Vol 397-400 ◽  
pp. 1611-1614
Author(s):  
Rui Bin Zhao ◽  
Rui Li ◽  
Zhi Gang Huang ◽  
Bo Shao
Keyword(s):  
Fault Detection ◽  
Estimation Method ◽  
Engineering Application ◽  
Estimation Algorithm ◽  
Satellite Clock ◽  
Clock Error ◽  
Wide Area Augmentation System ◽  
Integrity Risk ◽  
Position Solution ◽  
Satellite Clock Error

The fault detection and exclusion (FDE) algorithm played a very important role in the Wide Area Augmentation System (WAAS). When the WAAS was not available, the FDE algorithm could provide the monitored information for the navigation position solution. It could autonomously provide the integrity monitoring for the position solution, which it had a capability to detect and prevent a positioning failure that affected the navigation. An optimizing evaluation of estimation method was employed in detecting and isolating the outlying measurements for the satellite ephemeris error and the satellite clock error, which could assess the integrity risk in the WAAS. Therefore this algorithm could provide more precise integrity parameters of the satellite ephemeris error and clock error, which the method is more suitable at the master station for engineering application about the satellite.

Integrity monitoring of carrier phase-based ephemeris fault detection

GPS Solutions ◽  
2020 ◽  
Vol 24 (2) ◽  
Author(s):  
Liang Li ◽  
Xiaosong Liu ◽  
Chun Jia ◽  
Chun Cheng ◽  
Jiaxiang Li ◽  
...  
Keyword(s):  
Fault Detection ◽  
Carrier Phase ◽  
Integrity Monitoring

scholarly journals Ambiguity Resolution In Precise Point Positioning Technique: A Case Study

2015 ◽  
Vol 5 (1) ◽  
pp. 53-60 ◽  
Author(s):  
S. Nistor ◽  
A. S. Buda
Keyword(s):  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Precise Point Positioning ◽  
Main Idea ◽  
Convergence Time ◽  
Powerful Method ◽  
Satellite Clock ◽  
Positioning Technique ◽  
Point Positioning

Abstract Because of the dynamics of the GPS technique used in different domains like geodesy, near real-time GPS meteorology, geodynamics, the precise point positioning (PPP) becomes more than a powerful method for determining the position, or the delay caused by the atmosphere. The main idea of this method is that we need only one receiver – preferably that have dual frequencies pseudorange and carrier-phase capabilities – to obtain the position. Because we are using only one receiver the majority of the residuals that are eliminated in double differencing method, we have to estimate them in PPP. The development of the PPP method allows us, to use precise satellite clock estimates, and precise orbits, resulting in a much more efficient way to deal with the disadvantages of this technique, like slow convergence time, or ambiguity resolution. Because this two problem are correlated, to achieve fast convergence we need to resolve the problem of ambiguity resolution. But the accuracy of the PPP results are directly influenced by presence of the uncalibrated phase delays (UPD) originating in the receivers and satellites. In this article we present the GPS errors and biases, the zenith wet delay and the necessary time for obtaining the convergence. The necessary correction are downloaded by using the IGS service.

Autonomous Fault Detection with Carrier-Phase DGPS for Shipboard Landing Navigation

Navigation ◽  
2004 ◽  
Vol 51 (3) ◽  
pp. 185-197 ◽  
Author(s):  
MOON-BEOM HEO ◽  
BORIS PERVAN ◽  
SAM PULLEN ◽  
JENNIFER GAUTIER ◽  
PER ENGE ◽  
...  
Keyword(s):  
Fault Detection ◽  
Carrier Phase ◽  
Landing Navigation ◽  
Shipboard Landing

Experimental observations of carrier phase acceleration in conditions of polar ionosphere

2016 ◽  
Vol 61 (10) ◽  
pp. 1086-1090
Author(s):  
V. V. Demyanov ◽  
Yu. V. Yasyukevich ◽  
T. V. Kashkina ◽  
I. F. Gamayunov
Keyword(s):  
Carrier Phase ◽  
Polar Ionosphere ◽  
Phase Acceleration

scholarly journals The CODE ambiguity-fixed clock and phase bias analysis products: generation, properties, and performance

2021 ◽  
Vol 95 (7) ◽  
Author(s):  
S. Schaer ◽  
A. Villiger ◽  
D. Arnold ◽  
R. Dach ◽  
L. Prange ◽  
...  
Keyword(s):  
Carrier Phase ◽  
Observation Data ◽  
Satellite Clock ◽  
International Gnss Service ◽  
Bias Analysis ◽  
Phase Measurements ◽  
Phase Bias ◽  
Code Ambiguity ◽  
High Level ◽  
Cycle Property

AbstractThe generation and use of GNSS analysis products that allow—particularly for the needs of single-receiver applications—precise point positioning with ambiguity resolution (PPP-AR) are becoming more and more popular. A general uncertainty concerns the question on how the necessary phase bias information should be provided to the PPP-AR user. Until now, each AR-enabling clock/bias representation method had its own practice to provide the necessary bias information. We have generalized the observable-specific signal bias (OSB) representation, as introduced in Villiger (J Geod 93:1487–1500, 2019) originally exclusively for pseudorange measurements, to carrier phase measurements. The existing common clock (CC) approach has been extended in a way that OSBs allowing for flexible signal and frequency handling between multiple GNSS become possible. Advantages of the proposed OSB-based PPP-AR approach are: GNSS biases can be provided in a consistent way for phase and code measurements and it is capable of multi-GNSS and suitable for standardization. This new, extended PPP-AR approach has been implemented by the Center for Orbit Determination in Europe (CODE). CODE clock products that adhere to the integer-cycle property have been submitted to the International GNSS Service (IGS) since mid of 2018 for three analysis lines: Rapid, Final, and MGEX (Multi-GNSS Extension). Ambiguity fixing is performed not only for GPS but also for Galileo. The integer-cycle property of between-satellite clock differences is of fundamental importance when comparing satellite clock estimates among various analysis lines, or at day boundaries. Both kinds of comparisons could be exploited at a very high level of consistency. Any retrieved comparison essentially indicated a standard deviation for between-satellite clocks from CODE of the order of 5 ps (1.5 mm in range). Finally, the integer-cycle property that may be recovered between the CODE Final clock and the accompanying bias product of consecutive daily sessions (using clock estimates additionally provided for the second midnight epoch) allows us to deduce GPS satellite clock and phase bias information that is consistent and continuous with respect to carrier phase observation data over two, three, or, in principle, yet more days. Phase-based clock densification from initially estimated integer-cycle-conform clock corrections at intervals of 300 s to 30 s (5 s in case of our Final clock product) is a matter of particular interest. Based on direct product comparisons and GRACE K-band ranging (KBR) data analysis, the quality of accordingly densified clock corrections could be confirmed to be on a level similar to that of “anchor” (300 s) clock corrections.

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