• Journal of Korean Society for Geospatial Information Science
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• v.23 no.2
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• pp.79-88
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• 2015

In any production and construction of geospatial information covering surveying, survey control point is a vital geospatial information. Survey control points in South Korea are currently classified as following: national control points, public control points, and cadastral control points. Each of these different categories of survey control points act as a basis and sets perimeters for the production, management and operation of subjects within the category. Universal standard, the unified format between different survey control points, also, are not yet defined, causing difference in basic information provided by altering categories and disturbance in connecting, managing, utilizing and operating survey control points. Establishment of a standard regarding survey control points, is therefore required for the efficacy of their utilization. This study, to solve such inadequacies, selects management items for creation of standardized survey control point, by investigating domestically and internationally the status of operating survey control points, determining data model for management, establishing TTA and agency standards, and establishing of activation methodology for survey control point standards.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.167-172
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• 2002

본 연구는 GPS를 이용하여 위성 영상의 입체 해석으로 산출된 SPOT영상의 기준점 및 수치 표고 모형의 평가에 목적이 있다. 이를 위해 삼각점 및 상시관측소를 고정으로 한 GPS 해석을 수행하였으며 정지측량과 이동측량의 정확도를 비교함으로써 위성 영상의 기준점과 수치 표고 모형의 평가를 위한 측량 방법을 분석하였다. 연구 결과, SPOT영상의 해상력을 고려할 때, 이동 GPS측량기법으로도 수치 표고 모형의 정확도 평가가 가능하였으며, 기준점 좌표 산출에 있어서 고정점에 삼각점 대신 상시관측점들을 사용함으로써 경제적인 GPS 측량을 꾀할 수 있었다.

• Journal of Cadastre & Land InformatiX
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• v.53 no.2
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• pp.93-106
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• 2023

The objective of this study is to improve the survey rate and reliability of survey control point marks, which serve as the foundation for location-based services. Within the scope of this research, we have inspected the current status and reporting systems for national control point marks, public control point marks, and cadastral control point marks, identifying various issues. To tackle these challenges, we have prepared proposals for new unit cost calculations for national control point mark inspections, enhancements to the inspection and reporting systems for survey control point marks, and preliminary reporting procedures for surveyors using these control point marks. Additionally, we have established a workflow to refine the process of survey control point mark inspections and have proposed an automated system for calculating the unit cost for unreported targets. The study anticipates that these changes will improve the efficiency of future survey control point mark inspection tasks.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.1
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• pp.99-107
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• 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
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• v.6 no.2
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• pp.34-41
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• 1988

Nowadays the considerable improvements, not only in photogrammetric equipment but also in adjustment methods have led to a high accuracy of Aerial Triangulation and reach the step to obtain A.T. technique that uses Global Position System without ground control survery. The enterance of analytical plotter have made considerable development both in accuracy and in efficiency and improved working environment of A.T. by the combination of On-Line Analytical Plotting System. In this paper, in A.T., with using of analytical polotter, aims to improve the acccuracy in coordinates determination of low level control point. The result shows that in case of A.T. with analytical plotter AVIOLYT BC2, the accuracy of control points improves to 7% in planimetry and to 40% in height compared to A.T. with precision plotter Autograph A-8.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.78-90
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• 2021

In order to construct a precision geoid, it has been diversified into land, sea, aviation, and satellite gravity measurement methods, and measurement technology has developed, making it possible to secure high-resolution, high-precision gravity data. The construction of precision geoids can be fast and conveniently decided through GNSS surveys without separate leveling, and since 2014, the National Geographic Information Institute has been developing a hybrid geoid model to improve the accuracy of height surveying based on GNSS. In this study, the results of the GNSS height measurement were compared and analyzed choosing existing public reference points to verify the GNSS height measurement of public surveys. Experiments are conducted with GNSS height measurements and analyzed precision for public reference points on coastal, border, and mountainous terrain presented as low-precision areas or expected-to-be low-precision in research reports. To verify the GNSS height measurement, the GNSS ellipsoid height of the surrounding integrated datum to be used as a base point for the GNSS height measurement at the public datum. Based on the checked integrated datum, the GNSS ellipsoid of the public datum was calculated, and the elevation was calculated using the KNGeoid18 model and compared with the results of the direct level measurement elevation. The analysis showed that the results of GNSS height measurement at public reference points in the coastal, border, and mountainous areas were satisfied with the accuracy of public level measurement in grades 3 and 4. Through this study, GNSS level measurement can be used more efficiently than existing direct level measurements depending on the height accuracy required by users, and KNGeoids 18 can also be used in various fields such as autonomous vehicles and unmanned aerial vehicles.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.177-186
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• 2009

Nowadays, as going to information society based knowledge, the informations are acquired, processed, serviced based digital environment. In surveying field, the trend have been changed from the analog foundation to the digital foundation. Also, aerial photogrammetry is being changed from analog aerial photogrammetry to digital aerial photogrammetry. In this paper, the analysis of accuracy is performed for the comparison of traditional aerial photogrammetry with digital aerial photogrammetry usign UltracamX in AT and Block Adjustment. As the results, Bundle adjustment in digital aerial photogrammetry with GPS/INS have more advantages than traditional independent adjustment in analog aerial photogrammetry. Digital aerial photogrammetry contributes the higher accuracy in AT and block adjustment more than analog aerial photogrammetry.

• Spatial Information Research
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• v.20 no.5
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• pp.111-118
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• 2012

Survey control points managed by national and local governments are associated with civilian's property and they are very important national facilities. Despite the importance of surveying results, Database and mark of survey control points, there are many problems noticed of the management aspects such as manpower, systems, and related law. Currently, each local government has built and operated Geographic Information System(GIS) independently by National Geographic Information Systems(NGIS) results. but it is still difficult to have the integration, linking and utilizing. Therefore, In this study proposed the functional improvement of GIS based control points integrated system for providing information and management and the establishment of first-payment system due to the moving of control points. Through this studies will be able to solve the problem of recovery charges according to unknown contractor and establish the basis of manager and user-centric one-stop integration system.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.39-45
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• 2016

In this study, with arbitrary reference points on the water, photogrammetry accuracy analysis was conducted using unmanned aerial vehicle(UAV). A small reservoir is a research area, and twenty buoys were used as arbitrary reference points. Errors of location coordinate were identified with control of amounts of used reference points. cases are categorized by index scores per photos. Accuracy of X is 0.141m~0.166m and accuracy of Y is 0.136m~0.241m. Considering that allowable error for the maritime boundary survey is ${\pm}2m$, it is possible to get the accuracy data available for the photogrammetry of UAV using an reference point. In addition, the coefficient of correlation between the number of reference points per unit and number of buoys used as reference point and the ratio of the reference point per square measure, and percentage of buoys used as reference point and the coefficient of x and y were performed. Each element, x, and y showed a strong correlation and the coefficient of number of buoys used as reference point was irrelevant. The results of this correlation analysis can be analyzed that the number of reference points used in each picture is greater than the actual number of reference points used in location accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.179-186
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• 2010

In this research, an effective method for absolute positioning of feature points is proposed, which is applicable to geo-referencing of terrestrial LiDAR data scanned in dense urban areas. GPS positioning, common in absolute positioning, is apt to fail in the presence of signal disturbancein dense urban circumstances, while traditional surveying methods, including traversing and leveling, are generally more costly for wider areas. The idea is that reference points, marked on top of buildings, are surveyed by GPS positioning and then feature points are relatively positioned from the reference points. The present method, if laser scanning is accompanied, gets two advantages; one is that less feature points need to be surveyed because they can be substituredby reference points, and the other is that laser scanning can be more stably carried out. The present method was shown, from the experiments, to be cost-effective against traditional ones.