• Journal of Korean Society for Geospatial Information Science
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• v.10 no.3 s.21
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• pp.53-59
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• 2002

Territorial sea baseline is a borderline, with the effectuation of the United Nations Convention on the Law of the Sea of 1982, for the related sea zone negotiations with neighboring countries. Its position must be determined to international standard like WGS84 coordinate system. In this study, GPS survey for territorial sea points was performed to determine territorial baseline around five islands in the yellow sea, and the results of them were compared with previous coordinates. Territorial sea point, outermost spot of a nation's realm, tend to be placed in end up low-tide elevations or precipice. Therefore traditional surveying methods are hard to take accurate observations, so that GPS survey is most effective. Through the study, the scientific and reasonable methods for GPS surveying procedure is presented. The results of coordinate comparison show that there are wide difference between the old and new coordinates, and it is necessary for the whole area of islands to calculate displacements by GPS surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.205-211
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• 1999

In this study, we utilized 2D conformal transformation method to give coordinatesbased on GPS surveying data to NAHMIS (National Highway Management Information System) drawings which are lack of coordinates. To determine the best method which is comparable with GPS digital map, we compared a transformation result obtained by unique parameters applied to the whole region of about 20 km of the NAHMIS drawings and the similar result of the tile based transformations. As the result of map joining, the error was within 2 m for both cases. In this way, NAHMIS can be used for a systematic management of construction drawings. Moreover, NAHMIS can contribute the management of highway and the data exchange between other systems by a unification of coordinate system.

• Korean Journal of Geomatics
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• v.3 no.1
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• pp.73-79
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• 2003

To manage national territory and cadastral data efficiently, accuracy and cost-efficiency in cadastral boundary surveying is inevitable. The efficient management of cadastral data is a very important element in national land management. Survey techniques are being introduced. Recently, improvements in survey techniques have been made with the development of satellite surveying, Allowing accurate and fast surveys. If we can calculate the output accurately in real-time in survey fields, it will open a new method in cadastral detail surveying. According to the classification on Law of cadastral surveying, Cadastral surveying can be divided into cadastral control point surveying and cadastral detail surveying. The control point survey can be divided into cadastral triangulation surveying and cadastral traverse surveying. The detailed survey is usually perform by plane surveying. Among these, cadastral detail surveying will be reviewed in this study. In this study, the combination of the satellites, such as US managed GPS and Russian managed GLONASS was used. In the satellite survey in downtown, data interruption symptoms arose(according to the mask angle of the satellite). Therefore; we combined the satellites to get date more accurately. A block of Haewoondae New City in Busan, Korea, which has Numerical Cadastral Law was selected as the sample area for this study. Block II and III are surrounded by high rise apartments. One side of Block I and IV is level ground and the other side is full of high rise apartments. Especially, Block II is surrounded by high rise apartment houses with 20 meters width. In the results of the study Block II did not satisfy the allowable precision, while Block I, II and IV satisfied the allowable precision of the enforcement regulations of Cadastral Law. Therefore, it is judged that the traditionally used Total Station method should be used for supplementary survey on Block II, in stead.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2005.02a
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• pp.51-62
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• 2005

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.279-286
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• 2018

In the civil works, the measurement of earth-volume is one of the important elements in the estimation of the reasonable construction cost. Related studies mainly used GPS (Global Positioning System) or total station to obtain information on civil work areas. However, these methods are difficult to implement in inaccessible areas. Therefore, the aim of this paper is to use the UAV (Unmanned Aerial Vehicle) to measure the earth-volume. The study area is located in a reservoir construction site in Sangju-si, Gyeongsangbuk-do, Republic of Korea. We compared the earth-volume amounts acquired by UAV-based surveying to ones acquired by total station-based and GPS-based surveying, respectively. In the site, the amount of earth-volume acquired by GPS was $147,286.79m^3$. The amount of earth-volume acquired by total station was $147,286.79m^3$, which is the 96.13% accuracy compared to the GPS-based surveying. The earth-volume obtained by UAV was $143,997.05m^3$ when measured without GCPs (Ground Control Points), $147,251.71m^3$ with 4 GCPs measurement, and $146,963.81m^3$ with 7 GCPs measurement. Compared to the GPS-based surveying, 97.77%, 99.98%, and 99.78% accuracies were obtained from the UAV-based surveying without GCP, 4 GCPs, and 7 GCPs, respectively. Therefore, it can be confirmed that the UAV-based surveying can be used for the earth-volume measurement.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.33-38
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• 2002

The object of this study is to verify the feasibility in the application of the GPS system data to the existing geodetic and cadastral survey system. WGS-84 data, which were converted into domestic geometric coordinate system, were compared with those of the existing triangular coordinate system in Gwangju area. The significant results in this study are summarized below ; GPS system is more speedy and accurate than the existing triangular coordinate system in the survey of points in triangular coordinate or on the map. And the error in the GPS system was more uniform than that of the existing triangular coordinate system. GPS system is more effective than the existing triangular coordinate system in the future geodetic and cadastral survey because GPS data can be processed by the computer. It is necessary to calculate the conversion coefficients to apply GPS data practically to the existing geodetic and cadastral survey system. It can be achieved by the individual investigation on how the existing data in the domestic coordinate system were determined.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.232-238
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• 2007

In this research, we constructed a 3D riverbed surveying system that is able to acquire the topographical information of a riverbed in real-time. The system consists of a RTK-GPS receiver and a echo sounder for collecting simultaneously the position and the water depth information of riverbed. A program for data composition and transformation was designed to generate the 3D coordinates by combining data of a GPS receiver and a echo sounder and made GIS database construction easy. We extracted TIN, digital elevation model and cross sectional maps of the riverbed by using GIS software from 3D data constructed through test surveying. It was shown that the accuracy of the result was RMS error of 0.069m when compared with the existing methods which use a total station and staffs. It is expected that the 3D riverbed surveying system wiil be able to be utilized to various surveying for water resources management in rivers, sea, dams, storing reservoirs and so forth.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.97-101
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• 2003

Among GPS methods, first of all, we used RTK GPS to analyze the precision of monitoring and then on the basis of it, we developed a monitoring system using RTK GPS when we measured the behavior of main tower of a suspension bridge by using RTK GPS method and IMU, which was an inertia navigation system. Comparing a deviation between observation value using IMU and RTK GPS, X axis was 1mm, Y axis 1mm and Z axis 2.21mm. It turned out that it was possible to monitor and measure structures by using RTK GPS method. Besides, in order to manage the structures and prevent their disaster, the transformed monitoring, which used dynamic RTK GPS measurement method, was applied in real time. It was verified that it could be used as transformed monitoring measurement method for massive structures.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.131-137
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• 2004

GPS/Meteorology technique for PWV monitoring is currently actively being researched an advanced nation. We deal with the monitoring of GPS derived PWV during the passage of Typhoon MAEMI. Typhoon MAEMI which caused a series damage was passed over in Korea peninsula from September 12 to September 13, 2003. We obtained GPS-PWV at 17th GPS permanent stations. We retrieve GPS data hourly and use Gipsy-Oasis II software. The GPS-PWV time series results demonstrate that PWV is, in general, high before and during the occurrence of the typhoon, and low after the typhoon.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.105-110
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• 2006

우리나라에 GPS 위성측량이 도입되기 시작한 것은 최근에 이루어 졌으며 많은 발전을 해오고 있지만 해결해야 할 많은 문제점을 가지고 있다. 현재 우리나라의 GPS 위성측량의 사용에 있어서 여러 가지 문제점 중 현재 지구 주위를 운항하고 있는 24개의 GPS 위성으로 지상 어느 곳에서나 24시간 동안 위성신호를 수신할 수 있게 되었지만 고층 빌딩과 같은 도심 계곡, 복잡한 한국지형, 산악지역 등에서의 위성 장애물에 의한 신호의 차단으로 한계가 발생하고 있다. NAVSYNC의 CW25 GPS 수신기는 -156dBm이하의 신호강도에서도 확실한 위치 fix가 가능하고, 이러한 능력은 도심지나, 울창한 숲과 심지어는 건물 안과 같이 신호가 미약한 지역에서도 사용될 수 있다. 이에 본 연구에서는 Indoor GPS 수신기를 이용하여 측지분야에서 검증된 GPS측량방법을 통해 수신데이터를 비교 분석하고 수신기의 정밀도 향상에 관한 연구를 하고자 한다.