Estimation and Validation of Integer Ambiguity in Carrier Phase GPS Positioning

Abstract. Once the unknown integer ambiguity values are resolved, the GPS carrier phase observation will be transformed into a millimeter-level precision measurement. However, GPS observation are prone to a variety of errors, making it a biased measurement. There are two components in identifying integer ambiguities: estimation and validation. The estimation procedure aims to determine the ambiguity's integer values, and the validation step checks whether the estimated integer value is acceptable. Even though the theory and procedures for ambiguity estimates are well known, the topic of ambiguity validation is still being researched. The dependability of computed coordinates will be reduced if a false fixed solution emerges from an incorrectly estimated ambiguity integer value. In this study, the reliability of the fixed solution obtained by using several base stations in GPS positioning was investigated, and the coordinates received from these bases were compared. In a conclusion, quality control measures such as employing several base stations will improve the carrier phase measurement's accuracy.

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Using Future GNSS Multi-tone Signals for Increased Success in Carrier Phase Integer Ambiguity Fixing

Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018) ◽

10.33012/2018.15893 ◽

2018 ◽

Cited By ~ 1

Author(s):

Dominik D�tterb�ck ◽

Thomas Pany

Keyword(s):

Carrier Phase ◽

Integer Ambiguity ◽

Ambiguity Fixing

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Integration and Simulations of INS/GNSS System using the Approach of Carrier Phase Measurements

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v4i4.pp243-253 ◽

2015 ◽

Vol 4 (4) ◽

pp. 243

Author(s):

Khan Badshah ◽

Qin Yongyuan

Keyword(s):

Kalman Filtering ◽

Carrier Phase ◽

Closed Loop ◽

Position Estimation ◽

Integrated System ◽

Integer Ambiguity ◽

Font Size ◽

Phase Measurements ◽

Simulation Results ◽

Lever Arm Effect

This paper discusses the techniques of attitude, velocity ad position estimation from GNSS carrier phase measurements, and investigates the performance of the lower precision MEMS-based INS/GNSS system based on carrier phase measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, integer ambiguity is required to be removed for precise positioning. Multiples antennae approach is used to derive the attitude information from carrier phase measurements in order to control the large initial misalignment angles for initialization of the integration process or to utilize during benign dynamics. Lever arm effect is considered to compensate for the separation of GNSS antenna and IMU location. The derived three GNSS observables are used to correct the INS through optimal Kalman filtering in a closed loop. Simulation results indicates the effectiveness of the integrated system for airborne as well as for land navigation vehicles. <div id="_mcePaste" class="mcePaste" style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow: hidden;">This paper discusses the techniques of attitude, velocity ad position estimation from GNSS carrier phase measurements, and investigates the performance of the lower precision MEMS based INS/GNSS system based on carrier phase measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, integer ambiguity is required to be removed for precise positioning. Multiples antennae approach is used to derive the attitude information from carrier phase measurements in order to control the large initial misalignment angles for initialization of the integration process or to utilize during benign dynamics. Lever arm effect is considered to compensate for the separation of GNSS antenna and IMU location. The derived three GNSS observables are used to correct the INS through optimal Kalman filtering in a closed loop. Simulation results indicates the effectiveness of the integrated system for airborne as well as for land navigation vehicles. </div>

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Performance analysis of geometry‐free and ionosphere‐free code–carrier phase observation models in integer ambiguity resolution

IET Radar Sonar & Navigation ◽

10.1049/iet-rsn.2018.5036 ◽

2018 ◽

Vol 12 (11) ◽

pp. 1313-1319 ◽

Cited By ~ 1

Author(s):

Padma Bolla ◽

Jong‐Hoon Won

Keyword(s):

Performance Analysis ◽

Ambiguity Resolution ◽

Carrier Phase ◽

Integer Ambiguity Resolution ◽

Integer Ambiguity ◽

Phase Observation ◽

Carrier Phase Observation ◽

Free Code

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Performance Improvement of Time-Differenced Carrier Phase Measurement-Based Integrated GPS/INS Considering Noise Correlation

Sensors ◽

10.3390/s19143084 ◽

2019 ◽

Vol 19 (14) ◽

pp. 3084 ◽

Cited By ~ 2

Author(s):

Jungbeom Kim ◽

Younsil Kim ◽

Junesol Song ◽

Donguk Kim ◽

Minhuck Park ◽

...

Keyword(s):

Navigation System ◽

Carrier Phase ◽

Phase Measurement ◽

Integrated System ◽

Integer Ambiguity ◽

Noise Correlation ◽

Carrier Phase Measurement ◽

Phase Measurements ◽

Performance Improvements ◽

Global Positioning

In this study, we combined a time-differenced carrier phase (TDCP)-based global positioning system (GPS) with an inertial navigation system (INS) to form an integrated system that appropriately considers noise correlation. The TDCP-based navigation system can determine positions precisely based on high-quality carrier phase measurements without difficulty resolving integer ambiguity. Because the TDCP system contains current and previous information that violate the format of the conventional Kalman filter, a delayed state filter that considers the correlation between process and measurement noise is utilized to improve the accuracy and reliability of the TDCP-based GPS/INS. The results of a dynamic simulation and an experiment conducted to verify the efficacy of the proposed system indicate that it can achieve performance improvements of up to 70% and 60%, respectively, compared to the conventional algorithm.

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