• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.567-575
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• 2021

In order to correct the provided RPC and DEM generated from the high-resolution satellite images, the acquisition of the ground control point (GCP) must be preceded. This task is a very complicate that requires field surveys, GPS surveying, and image coordinate reading corresponding to GCPs. In addition, since it is difficult to set up and measure a GCP in areas where access is difficult or impossible (tidal flats, polar regions, volcanic regions, etc.), an alternative method is needed. In this paper, we propose a 3D surface matching technique using only the established ground coordinate package, avoiding the ground-image-location survey of the GCP to correct the DEM produced from WorldView-2 satellite images and the provided RPCs. The location data of the public control points were obtained from the National Geographic Information Institute website, and the DEM was corrected by performing 3D surface matching with this package. The accuracy of 3-axis translation and rotation obtained by the matching was evaluated using pre-measured GPS checkpoints. As a result, it was possible to obtain results within 2 m in the plane location and 1 m in height.

• Spatial Information Research
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• v.22 no.3
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• pp.23-24
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• 2014

NGII (National Geographic Information Institute) has been providing VRS (Virtual Reference Station) service so that could determine precise positioning in real time since 2007. However, since the VRS service has to maintain the connected status with VRS server, the number of users who can use VRS service are limited by capacity of VRS server. To solve this problem, NGII has been providing FKP (Virtual Reference Station) service using one way telecommunication from November 1, 2012. Therefore, it is predicted that the usage of FKP service will increase in public surveying and cadastral resurveying in the future. However, the studies with respect to analysis of FKP precision for applying to public surveying and cadastral resurveying is not conducted enough. In this study, to analyse the application possibility of FKP on the public surveying and cadastral resurveying, the two kind analysis were performed. First is the analysis of accuracy according to the configuration of reference station of FKP and VRS. One is consisted of same reference stations, another is consisted of different reference stations. Second is the accuracy anlalysis of horizontal and vertical positioning acquiring VRS and FKP data in various measurement environment based on VRS regulation. Result of first study, Positioning accuracy according to the configuration of the reference stations satisfies related regulation. However, accuracy of FKP in case of different reference stations is worse than in case of same reference stations.. The result of second test shows that the horizontal precision of FKP and VRS in good measurement environment satisfy the allowed precision. However, in some case, horizontal precision of FKP and VRS in poor measurement environment exceed the allowed precision. In addition, the number of exceeding the allowed precision in the FKP is more than the VRS. The vertical precision of the VRS satisfy related work provision. In conclusion, the result of this study shows that the FKP only in open area should be used for public survey and cadastral resurvey. Therefore the additional studies with respect to the improvement of FKP precision should be conducted.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.249-256
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• 2022

In the case of Drone Photogrammetry, the "pixel to point tool" module of Metashape, Pix4D Mapper, ContextCapture, and Global MapperGIS, which is a simple software, are widely used. Each SW has its own logic for the analysis of aerial triangulation, but from the user's point of view, it is necessary to select a SW by comparative analysis of the coordinate values of geospatial information for the result. Taking aerial photos for drone photogrammetry, surveying GCP reference points through VRS-GPS Survey, processing the acquired basic data using each SW to construct ortho image and DSM, and GCPSurvey performance and acquisition from each SW The coordinates (X,Y) of the center point of the GCP target on the Ortho-Image and the height value (EL) of the GCP point by DSM were compared. According to the "Public Surveying Work Regulations", the results of each SW are all within the margin of error. It turned out that there is no problem with the regulations no matter which SW is included within the scope.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.107-113
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• 1995

Generally, the objectives of the geodetic network adjustments are for solving the configuration of geodetic net-works and the problem of observation plans. In this study, assuming that the configuration is fixed, for improving the accuracy of geodetic networks, we focus on choosing adjustment control points and adjustment methods. By choosing adjustment control points and adjustment methods, the adjustment result accuracy of national geodetic networks can be different. So, in this study, we introduce the algorithm that use free network adjustment concept to minimize the displacements of new station points but fixing existing control points. Then, us-ing adjustment results, we can check the errors of existing control points. After checking the errors of existing control point, in case of severe error points in existing control points, we change those points into unknown station points and repeat the algorithm to optimize the coordinates of new station points. As applying this algorithm to simulation network, we can check the errors of existing control points. And changing severe error points into unknown station points, we can decrease the errors of network and optimize the coordinates of new station points. From the results of simulation network adjustment, we think that, as applying this algorithms to sequential adjustment of geodetic network and public surveying that using national geodetic network, the accuracy of network adjustments can be improved.

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

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.2
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• pp.101-107
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• 1985

The coordinates of triangulation stations which has been used in Korea, were computed by means of the Gauss Conformal Double Projection in the 1910's. This projection has been considered as a problem in respect of accuracy, because the farther a station is from the origin, the larger the computational error becomes. In this paper, the Gauss Conformal Double Projection is compared with the T.M(Transverse Metcator) Projection which is widely used in many countries. In T.M projection method more accurate ground coordinates are obtained. This paper has an objective to improve the accuracy of public surveying by using the method presented in this paper.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.146-151
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• 2006

현재 국가지리정보유통망을 통해 유통되고 있는 수치지도(Digital map)는 대부분 항공 측량사진(Air survey Photographs)이나 위성영상(Satellite images)을 통해 취득된 토지 피복의 형상을 기반으로 제작된 지도들이다. 정사사진으로부터 취득된 지형정보를 기호화, 단순화한 수치지도는 실제 사물의 형태와 많은 차이가 있어 지형과 시설물의 변이를 사실대로 반영하지 못한다. 특히 최근 들어 지하시설물이나 건축기술의 발달로 층별 구조가 다양해진 건축물의 형태 등은 정사사진으로는 식별이 불가능하고 건물의 경우 지붕의 형태로 묘사되는 등 표현에 한계가 있다. 도심지역을 대상으로 제작된 1/1,000수치지형도나 일부 지자체나 공공기관 등에서 제작된 $1/500{\sim}1/2,500$ 수치지형도는 상세한 지형정보를 포함하고 있는 높은 정밀도의 수치지도이지만, 도시지역의 변이가 빠르게 일어나고 있기 때문에 자료 신뢰성과 최신성을 유지하는데 한계가 있다. 따라서 본 연구는 현지조사나 측량에 의존하고 있는 정사사진으로부터 취득이 불가능한 지형자료의 취득이나 수년단위인 갱신주기의 한계를 극복하고 실시간으로 수치지도를 수정갱신 할 수 있는 대안으로 일반측량성과도의 활용방안을 제시하고자 한다. 일반측량업에서 생산되는 일반측량성과도는 임시 도근점에 의해 측량을 실시하고 지적경계점과 현황기지점을 도해법에 의해 지적도와 중첩시켜 제작한 측량도로서, 일반측량 성과도에 절대좌표체계를 부여하고 수치지도와 매칭 기법을 제시함으로서 경제적이고 신속한 실시간 수치지도 수정갱신체계를 확립할 수 있고, 자료의 공유함으로써 중복측량을 방지할 수 있다.보 등)를 활용, 구축된다. 교통분석용 네트워크는 구축시점에 따라 현재 및 장래 네트워크로 구분되며 장래 네트워크는 기준년도부터 2031년까지 5년 단위로 계획된 장래도로를 반영하여 구축된다. 교통주제도 및 교통분석용 네트워크는 국가교통DB구축사업을 통해 구축된 자료로서 교통체계효율화법 제9조의4에 따라 공공기관이 교통정책 및 계획수립 등에 활용할 수 있도록 제공하고 있다. 건설교통부의 승인절차를 거쳐 제공하며 활용 후에는 갱신자료 및 활용결과를 통보하는 과정을 거치도록 되어있다. 교통주제도는 국가의 교통정책결정과 관련분야의 기초자료로서 다양하게 활용되고 있으며, 특히 ITS 노드/링크 기본지도로 활용되는 등 교통 분야의 중요한 지리정보로서 구축되고 있다..20{\pm}0.37L$, 72시간에 $1.33{\pm}0.33L$로 유의한 차이를 보였으므로(F=6.153, P=0.004), 술 후 폐환기능 회복에 효과가 있다. 4) 실험군과 대조군의 수술 후 노력성 폐활량은 수술 후 72시간에서 실험군이 $1.90{\pm}0.61L$, 대조군이 $1.51{\pm}0.38L$로 유의한 차이를 보였다(t=2.620, P=0.013). 5) 실험군과 대조군의 수술 후 일초 노력성 호기량은 수술 후 24시간에서 $1.33{\pm}0.56L,\;1.00{\ge}0.28L$로 유의한 차이를 보였고(t=2.530, P=0.017), 술 후 72시간에서 $1.72{\pm}0.65L,\;1.33{\pm}0.3L$로 유의한 차이를 보였다(t=2.540, P=0.016). 6) 대상자의

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.39-54
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• 2017

Between 1998 and 2010, the computerization of underground facilities was completed in 84 cities. Since 2011, new pipelines have been laid or existing pipelines have been maintained, renovated, and renewed. To measure the exact location and depth of the exposure pipe, a map of underground facilities was created before filling the ground. This method is based on the time when the underground facilities of the National Geographic Information Institute Regulation No. 134 of the National Geographic Information Office revised in 2010 were drafted. The process of the drone taking the video is based on a theoretical basis of ground control points. The method works by removing all ground control points located outside of the error range and re-processing it for calculating the best result. Furthermore, using a drone-based spontaneous measuring method allows workers to obtain a high accuracy underground facilities map in error bound. The proposed method could be used as a new way to standardize the processing.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.151-157
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• 2013

The law for indicating the address based on the street name has taken effect in 1997. The address based on land-lot number will be changed to the address based on the street name giving odd numbers to the buildings situated on the left side and even numbers to the buildings situated on the right side per street. Searching locations by street name addresses is possible for residential areas, on the other hand, the system of finding locations is insufficient for farmlands, mountains and others, so it is unable to cope with crimes and emergency rescue. In order to make up for the weak points of street name address, the national point number, grid reference system was introduced for finding location of non-residential areas. Therefore, the purpose of this paper is to help the introduction the national point number. In this paper, we proposed a territory-oriented control point and grid range for the national point number. Numbering scheme of grid zone shall be alphanumeric, a two-letter pair Hangul and the grid coordinates in terms of Easting and Northing. We also proposed the notice area for the national point number and location of signs, application about the public and private sector.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.134-142
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• 2005

In building geographic information for North Korea, we proposed the method of using SPOT-5 image, designed geographic information layers, and inspected the location accuracy. Basically this study is similar to existing method in which uses GCPs to build geographic information from SPOT-5 satellite imagery. However, this study adopted a different method of GCP acquisition. The GCP used in this study is a triangulation point which was made at Japanese imperialism eras. The location accuracy error was 8.755 meters horizontally, which satisfied the tolerance of 17.5 meters in the 1:25,000 scale public survey guidance. In conclusion, we suggest that geographic information for North Korea can be built from SPOT-5 images with the triangulation point made in Japanese imperialism times.