• Journal of Korean Society for Geospatial Information Science
• /
• v.21 no.4
• /
• pp.117-123
• /
• 2013

The purpose of this research is to suggest the reasonable method of Network RTK surveying in future cadastral re-survey project through the accuracy analysis about Network RTK surveying achievement and the conventional TS-based confirmation surveying. To achieve it, we selected the experiment places and succeeded in achieving the result by Network RTK surveying about total of 307 parcel boundary point. We compared it with the result of confirmation surveying for cadastral, and it was shown that total connection errors of RMSE was ${\pm}0.1028m$ and total 48 places exceeded in the cadastral re-survey allowable error tolerance. The research suggested the practical alternatives in cadastral re-survey project after the comprehensive evaluation of those analysis results. Therefore, the author suggested development and adoptation of integrated electronic plane table surveying method. Moreover, we suggested unifying the first parcel boundary point method into the total station surveying and adopt the Network RTK surveying on the cadastral surveying inspection.

• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.4
• /
• pp.263-268
• /
• 2022

Precise Point Positioning-Real Time Kinematic (PPP-RTK) is a high accuracy positioning method that combines RTK and PPP to overcome the limitations on service coverage of RTK and convergence time of PPP. PPP-RTK provides correction data in the form of State Space Representation (SSR), unlike RTK, which provides measurement-based Observation Space Representation (OSR). Due to this, PPP-RTK has an advantage that it can transmit less data than RTK. So, recently, several techniques for PPP-RTK have been proposed. However, in order to utilize PPP-RTK techniques, performance analysis of these in a real environment is essential. In this paper, we implement the local network PPP-RTK and analyze the positioning performance according to the distance within 100 km from the reference station in Korea. As results of experiment, the horizontal and vertical 95% errors of local network PPP-RTK were 6.25 cm and 5.86 cm or less, respectively.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.479-484
• /
• 2015

Network RTK is a precise positioning technique using carrier phase correction data from reference stations within the network, and is constantly being researched for improved performance. However, the study for the system accuracy has been performed but system integrity research has not been done as much as system accuracy, because network RTK has been mainly used on surveying for static or kinematic positioning. In this paper, adequate monitoring system for network RTK is designed as basis research for integrity monitoring on network RTK. To this, fault tree on network RTK is analyzed, and a countermeasure is prepared to detect and identify the each fault items. Based these algorithms, monitoring system to use on central processing facility is designed for network RTK service.

• Journal of Korean Society for Geospatial Information Science
• /
• v.22 no.4
• /
• pp.39-46
• /
• 2014

Network RTK GNSS positioning technique which has been developed to overcome the limitation of Single reference station RTK is used widely in the field of general surveying, cadastre surveying and engineering surveying due to the high accuracy and efficiency. It is specified Network RTK, Single reference station RTK and Static of GNSS as a surveying method in the regulation of Cadastre Re-survey Surveying. In this study, Network RTK and Static GNSS surveying were accomplished at cadastral re-survey field in Hadong, Gyeongnam and the surveying results were compared. Also, to analyze the performance of site calibration in Network RTK surveying, two types of Network RTK surveying with and without site calibration were accomplished and the results was compared. The research result shows that average positioning error between Network RTK(VRS) without site calibration and Static surveying result is 2.44cm and 1.53cm respectively and average positioning error between Network RTK(VRS) with site calibration and Static surveying result is 0.19cm and 0.82cm respectively at two zone. So, it was proved the effect of calibration in network RTK(VRS) surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.2
• /
• pp.139-147
• /
• 2008

The positioning accuracies tend to deteriorate as the distance between the rover and the reference station increases in the Real-Time Kinematic (RTK) surveys using Global Positioning System (GPS). To solve this problem, the National Geographic Information Institute (NGII) of Korea has installed Virtual Reference System (VRS), which is one of the network-based RTK systems. In this study, we conducted the accuracy tests of the VRS-RTK surveys. We surveyed 50 control points inside the NGII's GPS Continuously Operating Reference Stations (CORS) network using the VRS-RTK system, and compared the results with the published coordinates to verify the positioning accuracies. We also conducted the general RTK surveys at the same control points. The results showed that the positioning accuracy of the VRS-RTK was comparable to that of the general RTK, because the horizontal positioning accuracy was 3.1 cm while that of general RTK was 2.0 cm. Also the vertical positioning accuracy of VRS-RTK was 6.8 cm.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.1
• /
• pp.99-107
• /
• 2013

With the expansion of the development and use of surveying equipment recently, by the establishment of infrastructure for network RTK surveying of the NGII, network RTK surveying has been widely used in surveying industry. Currently, in public surveying regulations, site calibration with minimum 5 evenly spaced bench marks is needed for using network RTK surveying results as leveling. But the range between and the number of bench marks for site calibration can be varied according to the geoid undulation. In this study, in order to verify this, Incheon area having regular geoid undulation and Taebaek area having irregular geoid undulation are selected as study area and network RTK surveying have been done. Then the accuracy of site calibration by range between and the number of bench marks have been compared. As a result of this study, in order to meet a tolerance of vertical precision (0.1m) that has been set in public surveying regulations, there is a necessity for improving the regulations so that the range and number of bench marks, to be used for site calibration of network RTK surveying, can be applied complementarily.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.4
• /
• pp.389-396
• /
• 2012

As the demand on the precise positioning for the moving objects has been increased in the various industry field, many studies have been conducted to analyze real time kinematic technique and its practical usage. The main purpose of this study is to analyze the possibility of Network-RTK(VRS) in real-time kinematic positioning. So, the accuracy analysis has been conducted by comparing the Network-RTK(VRS) position with respect to the RTK position. As a result, Network-RTK(VRS) based on kinematic positioning has centimeter level of RMS in the ideal environment compared to RTK positioning. However, when the integer ambiguities was lost, the accuracy of Network-RTK was meter level. At that time, the quality value has been changed dramatically and shows big correlation with accuracy. When the position and height quality values are within 0.1m, the RMS of the horizontal and vertical position appears better than 10cm and 20cm, respectively. However, if the quality value is over 0.1m, the RMS increases to larger than a meter. Therefore, it is recommended to check the quality value when conducting Network-RTK(VRS) kinematic positioning to get the centimeter level accuracy.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.16 no.4
• /
• pp.54-63
• /
• 2013

In this paper, we evaluate the accuracy of the vertical positioning by distance using Network RTK-GPS. The experimental results confirm that Network RTK-GPS method can acquire data quickly and accurately than conventional leveling methods so that the Network RTK-GPS method is a relatively efficient and economical way for the vertical positioning. Results of validation using permanent GPS stations indicate that visible satellites, PDOP, and VDOP are very good for the vertical positioning. Integrated reference points such as U0997 and U0921 are satisfied with 3 ratings in the rules of public leveling and all the rest are proved improper. When the vertical positioning using Network RTK-GPS is implemented, the geoid height of EGM2008 should be applied for leveling. If the number of geodetic satellite are increasing in the near future, the vertical positioning using Network RTK-GPS can be possible in all the range.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.35-41
• /
• 2016

GNSS/Geoid positioning technology allows orthometric height determination using both the geoidal height calculated from geoid model and the ellipsoidal height achieved by GNSS survey. In this study, Network-RTK surveying was performed through the Benchmarks in the study area to analyze the possibility of height positioning of the Network-RTK. And the orthometric heights were calculated by applying the Korean national geoid model KNGeoid13 according to the condition of with site calibration and without site calibration and the results were compared. Simplex algorithm was adopted for liner programming in this study and the heights of all Benchmarks were calculated in both case of applying site calibration and does not applying site calibration. The results were compared to Benchmark official height of the National Geographic Information Institute. The results showed that the average value of the height difference was 0.060m, and the standard deviation was 0.072m in Network-RTK without site calibration and the average value of the height difference was 0.040m, and the standard deviation was 0.047m in Network-RTK with the application of the site calibration. With linearization method to obtain the optimal solution for observations it showed that the height determination within 0.033m was available in GNSS Network-RTK positioning.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.2
• /
• pp.424-431
• /
• 2017

These days land vehicle navigation system is a subject of great interest. The GNSS(Global Navigation Satellite System) is the most popular technology for out door positioning. However, The GNSS is incapable of providing high accuracy and reliable positioning. For that reason, we applied Network-RTK in vehicle to improve the accuracy of GNSS performance. In this network-RTK mode, the GNSS error are significantly decreased. In this paper, we explain ntrip client program for network-RTK mode and show the result of experiments in various environments.