• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.59-63
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• 2006

본 연구의 목적은 GPS관측에 의한 세계측지계 성과의 산출방안을 연구하는데 그 목적이 있다. GPS 관측 데이터와 상시관측소의 데이터를 활용하여 세계측지계 성과를 산출하기 위한 방안을 연구한다. GPS 관측 데이터의 후처리 결과 상시관측소의 데이터를 사용하지 않았을 경우와 사용하였을 경우의 폐합차를 분석한 결과 모두 정밀1차 기준점 측량작업규정에 만족함을 알 수 있었다. 또한 GPS상시관측소의 데이터를 활용하여 각 측점 지점의 좌표를 산출한 결과, 상시관측소 3개소의 데이터를 사용하였을 경우에 비해 사용하지 않았을 경우의 오차가 가장 크게 나타났으며 1개소 사용, 2개소 사용할 때 점차적으로 오차가 감소하고 있음을 알 수 있었다. 따라서 상시관측소를 고정점으로 사용하되 적어도 3점이상의 점을 사용하여야 함을 알 수 있었다. 본 연구는 제한된 일부 지역을 대상으로 GPS 상시관측소의 관측 데이터를 사용하여 세계측지계의 성과를 산출 한 연구로 향후 광범위한 지역에서의 GPS 상시관측소의 활용에 대한 심도 있는 연구가 진행되어야 할 것이다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.299-307
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• 2007

This study is about the calculation of practical orthometric height for permanent GPS station. We presented the method to determine the orthometric height precisely by combining leveling data, GPS data and gravimetry data, and determined the orthometric heights of thirty GPS stations. To test the result we developed the expected error model fur the determined orthometric heights regarding the accuracy of Korean national benchmarks and the precision of surveying methods used at this project. The reliability of the results was presented by comparing it with expected error model statistically.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.499-505
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• 2004

현재 국내에서 활발히 이루어지고 있는 GPS 정밀측지측량은 획득된 GPS 관측값의 결과값이 GPS 기준점의 기하학적 강도와 분산계수의 상관관계의 연관성과의 분석없이 사용되고 있는 문제점을 파악하고 육지와 해상의 통합지리정보시스템구축을 위한 수치지도와 전자해도의 통합투영의 필요성에 의해서 이루어졌다. 본 연구의 목적은 크게 GPS 관측값의 정밀도를 향상시키는 방법과 수치지도와 전자해도의 통합투영으로 GPS 기준점들을 이용한 수치지도와 전자해도상의 경계선 오차량을 비교검토를 통해 수치지도와 전자해도의 통합관리의 방향을 제시하는데 있다. GPS 관측값의 정밀도 향상을 위한 방법제시를 위하여 GPS 망조정에 사용되는 3점의 기준점에 대한 기하학적인 강도에 따른 정밀도 분석방법과 분산계수의 변화에 따른 GPS 관측값들의 정밀도 분석방법으로 나누어 검토하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.275-281
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• 2004

Geodetic surveying using precise GPS equipment are used without analysis with a statistical verification of GPS observed value and it was preformed by necessity to integration projection of digital topographic map and nautical Chart for integration geographic information system construction. The purpose of this study proposes method that improve accuracy of GPS observed value and direction that integrally manage digital topographic map and electronic nautical chart in analyzing the boundary line error between digital topographic map and nautical Chart. For improvement of the precision of GPS observed value, the author studied precision-analysis of GPS observed value by geometric strength and variance factor in 3 control points used in GPS network adjustment. This study compare the whole boundary point error When producing EDM measurement using this GPS observation results and setting digital topographic map and nautical chart by these boundary.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.41-49
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• 2007

In this study, the software to compute Bessel coordinates by trilateration adjustment was developed, and the software was used to determine coordinates of the cadastral control points over the southern Korean peninsula. The baseline measured by GPS was reduced to the distance on geoid surface by applying PNU95 geoid model, and the distance on geoid surface was reduced to the plane grid distance by applying scale factor of map projection of Bessel coordinates. Using the plane grid distance, Bessel coordinates of 32 CORS (Continuously Operating Reference Station) were computed by free adjustment at first, and then the coordinates of the cadastral control points were computed by joining the control points to adjacent CORS. The result shows a possibility of construction of highly accurate and consistent cadastral survey network with coordinate error less than 1ppm of distance, when newly computing the coordinates of the control points by using distances measured by GPS.

• Spatial Information Research
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• v.12 no.4 s.31
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• pp.371-382
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• 2004

Continuously Operating Reference Stations (CORS) provides GPS measurements to support high accuracy CPS positioning. The CORS improves GPS positioning productivity by eliminating the requirement for GPS users to operate two receivers. Previously, this is achieved by providing data from CORS to users in post-mission mode. However, the efficiency of the CORS will be maximized by upgrading it in real-time operation using RTK-GPS surveying because users can obtain centimeter-level accuracy in real-time without operating their own reference stations. In this research, authors extracted the arbitrary point's coordinate which is using GPS CORS data, now served in RINEX FORMAT via Internet, with observation network of the existing triangulation and GPS CORS data. And then, RTK GPS was performed with this arbitrary point as reference station.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.269-274
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• 2005

Geodetic surveying using precise GPS equipment are used without analysis with a statistical verification of GPS observed value and it was preformed by necessity to integration projection of digital topographic map and nautical Chart for integration geographic information system construction. The purpose of this study proposes method that improve accuracy of GPS observed value and direction that integrally manage digital topographic map and electronic nautical chart in analyzing the boundary line error between digital topographic map and nautical Chart. For improvement of the precision of GPS observed value, the author studied precision-analysis of GPS observed value by geometric strength and variance factor in 3 control points used in GPS network adjustment. And like this, produce EDM measurement using this GPS observation results and compare the whole boundary point error when set digital topographic map and nautical chart by these boundary.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.83-90
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• 2002

Control point survey by GPS can save labor and time and can obtain result of high accuracy, but if excessive error is contained to Control point that is used to GPS relative positioning, the error that has influence on new point is propagated to various configuration. therefore poor triangulation points that are caused by careless management are existed, a product of the triangulation points still are in many case. In order to select new point, this study carried out error-analysis of surrounding-control-points and performed selective process of control point. The propriety parts of control points that are used to verify precision is identified by means of comparing existing product with or GPS product about some control points after directly observe each baseline by using EDM. As the error is analyzed by static positioning the optimum control point is selected, the precision of survey data by EDM is improved than GPS data.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.2 s.29
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• pp.29-35
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• 2004

The plenty of availability and high precision of GPS CORS is the reason why it become important more and more in the fields of surveying widely. In this study, I extracted the arbitrary point's coordinate which is using GPS CORS data, now served in RINEX FORMAT via Inter-Net, with observation network of the existing triangulation and GPS CORS data. Then, with this arbitrary point as reference station RTK GPS was performed. And I will study VRS-GPS concept which reduces the time and cost in the fields of surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.3
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• pp.237-247
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• 2011

As of 2011, 72 Permanent GPS Stations are installed to control DGPS reference points by the National Geographic Information Institute in South Korea. As the center of the Earth's mass continues to move, the coordinates of the permanent GPS stations become inconsistent over time. Thus, a reference frame using a set of coordinates and their velocities of a global network of stations at a specific period has been used to solve the inconsistency. However, the relative movement of the permanent GPS stations can lower the accuracy of GPS relative positioning. In this research, we first analyzed the data collected daily during the past 30 months at the 40 permanent GPS stations within South Korea and the 5 IGS permanent GPS stations around the Korean Peninsula using a global network adjustment. We then calculated the absolute and relative amount of movement of the GPS permanent stations. We also identified the optimum renewal period of the permanent GPS stations considering the accuracy of relative GPS surveying. Finally, we developed a Korean a Korean crustal movement model that can be used to improvement of accuracy.