scholarly journals Analysis of Attitude Determination Methods Using GPS Carrier Phase Measurements

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Leandro Baroni ◽  
Hélio Koiti Kuga
Keyword(s):  
Carrier Phase ◽  
Attitude Determination ◽  
Precise Determination ◽  
Integer Ambiguity ◽  
Integer Number ◽  
Method Performance ◽  
Phase Measurements ◽  
Double Differences ◽  
Number Of Cycles

If three or more GPS antennas are mounted properly on a platform and differences of GPS signals measurements are collected simultaneously, the baselines vectors between antennas can be determined and the platform orientation defined by these vectors can be calculated. Thus, the prerequisite for attitude determination technique based on GPS is to calculate baselines between antennas to millimeter level of accuracy. For accurate attitude solutions to be attained, carrier phase double differences are used as main type of measurements. The use of carrier phase measurements leads to the problem of precise determination of the ambiguous integer number of cycles in the initial carrier phase (integer ambiguity). In this work two algorithms (LSAST and LAMBDA) were implemented and tested for ambiguity resolution allowing accurate real-time attitude determination using measurements given by GPS receivers in coupled form. Platform orientation was obtained using quaternions formulation, and the results showed that LSAST method performance is similar to LAMBDA as far as the number of epochs which are necessary to resolve ambiguities is concerned, but with processing time significantly higher. The final result accuracy was similar for both methods, better than 0.1° to 0.2°, when baselines are considered in decoupled form.

scholarly journals A New On-The-Move Integer Ambiguity Determination Method for Precise Positioning of Highly Maneuvering Ground Vehicles

2019 ◽  
Vol 94 ◽  
pp. 01002
Author(s):  
Jong-Hwa Jeon ◽  
Sang-Hoon Yoo ◽  
Jeung-Won Choi ◽  
Tae-Kyung Sung
Keyword(s):  
Vehicle Dynamics ◽  
Carrier Phase ◽  
Integer Ambiguity ◽  
Dual Frequency ◽  
Ground Vehicles ◽  
Position Change ◽  
Precise Positioning ◽  
Precise Position ◽  
Phase Measurements

In the conventional RTK (Real Time Kinematics), carrier phase measurements should be collected for several minutes in stationary state in order to determine the IA (Integer Ambiguity) in carrier phase to get the precise position. To determine the IA in motion, several OTM-RTK (On-The-Move RTK) methods have been proposed using vehicle dynamics or augmenting additional sensors. This paper presents a new OTM-RTK technique to determine the IA without aids of external sensors for precise positioning of highly maneuvering ground vehicles. In the proposed technique, the initial IA is determined fast by estimating precise position change during epochs using dual frequency carrier phase measurements. Therefore, IA determination of the proposed method is not influence by vehicle dynamics. By field experiment, performance of the proposed technique is analyzed including IA determination time according to vehicle dynamics and the number of visible SV.

Survey Boat Attitude Determination with GPS/IMU Systems

2001 ◽  
Vol 54 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Reha Metin Alkan ◽  
Orhan Baykal
Keyword(s):  
Carrier Phase ◽  
Inertial Measurement Unit ◽  
Attitude Determination ◽  
Measurement Unit ◽  
Phase Measurements ◽  
Inertial Measurement ◽  
The Third ◽  
Hydrographic Surveying ◽  
Echo Sounder

Any vehicle such as a vessel or aeroplane has three attitude parameters. These are most commonly defined as pitch, roll and heading from true north. In hydrographic surveying, determination of these parameters is essential for the correction of multi-beam echo sounder measurements. In the study on which this paper is based, two of the three parameters, the pitch and roll angles, were measured with an inexpensive IMU (Inertial Measurement Unit) device. The third was calculated from GPS carrier phase measurements that were collected from two antennas on the boat. The GPS antennas depart from the vertical when they are subject to pitch and roll effects. In this case, the coordinates derived from GPS will be erroneous. Thus, if heading is to be calculated accurately, the horizontal coordinates have to be corrected for pitch and roll. This paper defines an algorithm for the purpose that enables pitch and roll angles to be measured with an accuracy of about 0·003 arcdeg and headings computed with an accuracy of about 0·010 arcdeg.

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

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

<p class="MsoNormal" style="margin-top: 12.0pt; margin-right: 0in; margin-bottom: 6.0pt; margin-left: 0in; text-align: justify;"><em><span style="font-size: 9.0pt; font-family: &quot;Arial&quot;,sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;" lang="EN-GB">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<span style="color: red;"> </span>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</span></em><span lang="EN-GB">. </span></p><div id="_mcePaste" class="mcePaste" style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow: hidden;"><p class="MsoNormal" style="margin-top: 12.0pt; margin-right: 0in; margin-bottom: 6.0pt; margin-left: 0in; text-align: justify;"><em><span style="font-size: 9.0pt; font-family: &quot;Arial&quot;,sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;" lang="EN-GB">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<span style="color: red;"> </span>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</span></em><span lang="EN-GB">. </span></p></div>

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

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3084 ◽  
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.

Improving the Performance of INS/GNSS System Using the Approach of Carrier Phase Measurements

2015 ◽  
Vol 21 ◽  
pp. 172-183
Author(s):  
Badshah Khan ◽  
Yong Yuan Qin
Keyword(s):  
Carrier Phase ◽  
Closed Loop ◽  
Position Estimation ◽  
Integrated System ◽  
Integer Ambiguity ◽  
Gps Receiver ◽  
Position Measurement ◽  
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. Generally, a GPS receiver estimates the position and velocity from code phase and Doppler measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, for position measurement, the integer ambiguity is required to be removed. 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.

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