Numerical verification algorithm for relative positioning accuracy between chang'e 2 and Asteroid Toutatis of 2012 Flyby

2014 ◽  
Author(s):  
Yanlong Bu ◽  
Geshi Tang ◽  
ChiBiao Ding ◽  
Junze Liu ◽  
Hongbing Xu ◽  
...  
Keyword(s):  
Numerical Verification ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
Verification Algorithm

Multi-resolution Visual Positioning and Navigation Technique for Unmanned Aerial System Landing Assistance

2017 ◽  
Vol 70 (6) ◽  
pp. 1276-1292
Author(s):  
Chong Yu ◽  
Jiyuan Cai ◽  
Qingyu Chen
Keyword(s):  
Real World ◽  
State Of The Art ◽  
Unmanned Aerial System ◽  
Detection Accuracy ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
Visual Positioning ◽  
Positioning Technique ◽  
Technique Comparison ◽  
Resolution Simulation

To achieve more accurate navigation performance in the landing process, a multi-resolution visual positioning technique is proposed for landing assistance of an Unmanned Aerial System (UAS). This technique uses a captured image of an artificial landmark (e.g. barcode) to provide relative positioning information in the X, Y and Z axes, and yaw, roll and pitch orientations. A multi-resolution coding algorithm is designed to ensure the UAS will not lose the detection of the landing target due to limited visual angles or camera resolution. Simulation and real world experiments prove the performance of the proposed technique in positioning accuracy, detection accuracy, and navigation effect. Two types of UAS are used to verify the generalisation of the proposed technique. Comparison experiments to state-of-the-art techniques are also included with the results analysis.

scholarly journals THE QUALITY OF OPENSTREETMAP IN MALAYSIA: A PRELIMINARY ASSESSMENT

2018 ◽  
Vol XLII-4/W9 ◽  
pp. 291-298 ◽  
Author(s):  
S. N. R. M. Husen ◽  
N. H. Idris ◽  
M. H. I. Ishak
Keyword(s):  
Relative Positioning ◽  
Reference Dataset ◽  
Preliminary Assessment ◽  
Positioning Accuracy ◽  
Open Platform ◽  
Collaborative Mapping ◽  
Mexico Earthquake ◽  
Thematic Accuracy ◽  
Hurricane Irma

<p><strong>Abstract.</strong> Over recent years, the phenomena, Web 2.0 has led to the growth of volunteered geographic information (VGI). The emergence of VGI has played an important role in providing timely data when the costs and its availability is a major concern particularly during emergency and humanitarian efforts. The worldwide crowdsourcing efforts through OpenStreetMap (OSM), the most successful open platform for collaborative mapping have managed to assist authorities such as during the 2017 Mexico earthquake and Hurricane Irma and Maria that impacted several countries in America continent. However, there are lots of arguments on the quality of VGI, particularly in regard to OpenStreetMap (OSM). Therefore, this study was carried out to assess the quality of OSM against authoritative sources using a dataset of Putrajaya, Malaysia. This study assessed the quality of OSM, including completeness, positional and thematic accuracy. From the preliminary assessment, the results showed that the OSM data was good in terms of relative positioning accuracy, particularly in road feature, but still poor in terms of completeness and thematic correctness against the reference dataset. This study is significant with an expected contribution to the assessment of quality of VGI in developing countries that commonly facing slow-paced progress in mapping the OSM. The findings could be used as a basis for various parties that plan to use OSM in Malaysia, particularly Putrajaya as a supplementary data to authoritative sources, including data supplied by the professional surveyors.</p>

scholarly journals RESEARCH OF POSITIONING ACCURACY BASED ON PHOTOGRAMMETRY

2020 ◽  
pp. 73-79
Author(s):  
Yu.M. Salamatina ◽  
S.I. Kuzikov
Keyword(s):  
Space Geodesy ◽  
Digital Model ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
3D Digital Model

The methods of ground and space geodesy allow to determine with millimeter accuracy the position of separate geodetic points on the Earth's surface. The hardware and software of the photogrammetry method make it possible to build a 3D digital model of the observed geodetic area. The purpose of this work is to compare and evaluate the accuracy of relative positioning using geodesy and photogrammetry methods within the Bishkek geodynamic area.

scholarly journals Mobile robot positioning algorithm based on Kalman filtering method in network environment

2020 ◽  
Vol 327 ◽  
pp. 03005
Author(s):  
Shuang Zhang
Keyword(s):  
Mobile Robot ◽  
Navigation System ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Measurement Unit ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
Reference Information ◽  
Absolute Positioning ◽  
Positioning Method

Positioning is the basic link in a multi-mobile robot control system, and is also a problem that must be solved before completing a specified task. The positioning method can be generally divided into relative positioning and absolute positioning. Absolute positioning method refers to that the robot calculates its current position by acquiring the reference information of some known positions in the outside world, calculating the relationship between itself and the reference information. Absolute positioning generally adopts methods based on beacons, environment map matching, and visual positioning. The relative positioning method mainly uses the inertial navigation system INS. The inertial navigation system directly fixes the inertial measurement unit composed of the gyroscope and the accelerometer to the target device, and uses the inertial devices such as the gyroscope and the accelerometer to measure the triaxial angular velocity and The three-axis acceleration information is measured and integrated, and the mobile robot coordinates are updated in real time. Combined with the initial inertial information of the target device, navigation information such as the attitude, speed, and position of the target device is obtained through integral operation [1-2]. The inertial navigation system does not depend on external information when it is working, and is not easily damaged by interference. As an autonomous navigation system, it has the advantages of high data update rate and high short-term positioning accuracy [3]. However, under the long-term operation of inertial navigation, due to the cumulative error of integration, the positioning accuracy is seriously degraded, so it is necessary to seek an external positioning method to correct its position information [4]

scholarly journals An Improved Long-Period Precise Time-Relative Positioning Method Based on RTS Data

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 53
Author(s):  
Yangwei Lu ◽  
Shengyue Ji ◽  
Rui Tu ◽  
Duojie Weng ◽  
Xiaochun Lu ◽  
...  
Keyword(s):  
High Precision ◽  
Reference Station ◽  
Positioning Error ◽  
Relative Positioning ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Long Period ◽  
Short Period ◽  
Positioning Method ◽  
Positioning Algorithm

The high precision positioning can be easily achieved by using real-time kinematic (RTK) and precise point positioning (PPP) or their augmented techniques, such as network RTK (NRTK) and PPP-RTK, even if they also have their own shortfalls. A reference station and datalink are required for RTK or NRTK. Though the PPP technique can provide high accuracy position data, it needs an initialisation time of 10–30 min. The time-relative positioning method estimates the difference between positions at two epochs by means of a single receiver, which can overcome these issues within short period to some degree. The positioning error significantly increases for long-period precise positioning as consequence of the variation of various errors in GNSS (Global Navigation Satellite System) measurements over time. Furthermore, the accuracy of traditional time-relative positioning is very sensitive to the initial positioning error. In order to overcome these issues, an improved time-relative positioning algorithm is proposed in this paper. The improved time-relative positioning method employs PPP model to estimate the parameters of current epoch including position vector, float ionosphere-free (IF) ambiguities, so that these estimated float IF ambiguities are used as a constraint of the base epoch. Thus, the position of the base epoch can be estimated by means of a robust Kalman filter, so that the position of the current epoch with reference to the base epoch can be obtained by differencing the position vectors between the base epoch and the current one. The numerical results obtained during static and dynamic tests show that the proposed positioning algorithm can achieve a positioning accuracy of a few centimetres in one hour. As expected, the positioning accuracy is highly improved by combining GPS, BeiDou and Galileo as a consequence of a higher amount of used satellites and a more uniform geometrical distribution of the satellites themselves. Furthermore, the positioning accuracy achieved by using the positioning algorithm here described is not affected by the initial positioning error, because there is no approximation similar to that of the traditional time-relative positioning. The improved time-relative positioning method can be used to provide long-period high precision positioning by using a single dual-frequency (L1/L2) satellite receiver.

Improvement of Relative Positioning Accuracy by Searching GPS Common Satellite between the Vehicles

2012 ◽  
Vol 16 (6) ◽  
pp. 927-934 ◽  
Author(s):  
Young-Min Han ◽  
Sung-Yong Lee ◽  
Youn-Sil Kim ◽  
June-Sol Song ◽  
Hee-Kwon No ◽  
...  
Keyword(s):  
Relative Positioning ◽  
Positioning Accuracy

Precise Spacecraft Relative Positioning using Single-Frequency Pseudorange Measurements

2008 ◽  
Vol 62 (1) ◽  
pp. 119-134 ◽  
Author(s):  
Marc-Philippe Rudel ◽  
Pini Gurfil
Keyword(s):  
Satellite Data ◽  
Carrier Phase ◽  
The Other ◽  
Single Frequency ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
Differential Corrections ◽  
Gravity Recovery ◽  
Grace Mission ◽  
Better Than

The ranging accuracy provided by pseudorange-only techniques is usually no better than a few metres when no differential corrections are applied. Carrier-phase algorithms, on the other hand, yield higher-precision estimates – down to a few millimetres – but are prone to ambiguities difficult to resolve. An easier-to-implement method, using single-frequency pseudorange measurements only, is presented. It allows for a decimetre-level relative positioning accuracy. Results, derived from the GPS Relative Positioning Equations, are validated with actual satellite data from the Gravity Recovery and Climate Experiment (GRACE) mission.

scholarly journals Single-Frequency Precise Point Positioning Using Regional Dual-Frequency Observations

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2856
Author(s):  
Junping Zou ◽  
Ahao Wang ◽  
Jiexian Wang
Keyword(s):  
High Precision ◽  
Precise Point Positioning ◽  
Low Cost ◽  
Deformation Monitoring ◽  
Convergence Time ◽  
Single Frequency ◽  
Relative Positioning ◽  
Dual Frequency ◽  
Positioning Accuracy ◽  
Point Positioning

High-precision and low-cost single-frequency precise point positioning (SF-PPP) has been attracting more and more attention in numerous global navigation satellite system (GNSS) applications. To provide the precise ionosphere delay and improve the positioning accuracy of the SF-PPP, the dual-frequency receiver, which receives dual-frequency observations, is used. Based on the serviced precise ionosphere delay, which is generated from the dual-frequency observations, the high-precision SF-PPP is realized. To further improve the accuracy of the SF-PPP and shorten its convergence time, the double-differenced (DD) ambiguity resolutions, which are generated from the DD algorithm, are introduced. This method avoids the estimation of fractional cycle bias (FCB) for the SF-PPP ambiguity. Here, we collected data from six stations of Shanghai China which was processed, and the corresponding results were analyzed. The results of the dual-frequency observations enhanced SF-PPP realize centimeter-level positioning. The difference between the results of two stations estimated with dual-frequency observations enhanced SF-PPP were compared with the relative positioning results computed with the DD algorithm. Experimental results showed that the relative positioning accuracy of the DD algorithm is slightly better than that of the dual-frequency observations enhanced SF-PPP. This could be explained by the effect of the float ambiguity resolutions on the positioning accuracy. The data was processed with the proposed method for the introduction of the DD ambiguity into SF-PPP and the results indicated that this method could improve the positioning accuracy and shorten the convergence time of the SF-PPP. The results could further improve the deformation monitoring ability of SF-PPP.

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