• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.169-175
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• 2009

According as standard of measurement is changed to world geodetic system by surveying law revision, we need to transform previous 1/1,000 digital maps as a standards of world geodetic system. And, we should acquire standard strategy to minimize confusion and error by conversion of geodetic surveying standards. Thus, conversion of digital maps must be transformed efficiently and consistently according to notice of relevant standard. As common point, we have used 1/1,000 digital map and local geodetic system coordinates and world geodetic system coordinates that had been used in UIS business of Pusan city and, make a analysis of distortion quantity using KASM Trans Ver 2.2. As the result of distortion quantity calculation about all Pusan city, numbers of area that error is over 0.05m are 35 in case of X(N) and 43 in case of Y(E). Because some business section have especially much error, we divided into 3 areas, that was A,B,C, and analyzed. As a result of analysis, errors of more than 0.05m are occurred only 1 X(E) in the B area and 1 X(N) and 1 Y(E) in the C area. In conclusion, We think It is a good method that we consider a distortion quantity and divide a region, and transfer to world geodetic system for large area like Pusan city.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.117-124
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• 1995

The main purpose of the present study was to investigate coordinate transformation based on two different systems: one was the World Geodetic System 1984(WGS84) adopted as a reference system for GPS satellite surveying;and another was the current Korean geodetic system based on Bessel ellipsoid. For this purpose, three methods were used to determine 7 parameters as follows: Bursa-Wolf model, Molodensky-Badekas model, and Veis model. The coordinate transformation was carried out using simillity transformation applied the obtained 7 parameters and the precision of transformed coordinate was evaluated. From this results, we found that Bursa-wolf model is more suitable than others for the determination of transformation parameters in Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.15-23
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• 2017

The WGS conversion project of cadastral drawing (promoted by the Ministry of Land) is not able to reflect the cadastral registration due to subtle differences such as area and location. When converting the digital cadastral region to the world geodetic system, the boundary point coordinates must be changed to the legal coordinate units. However, there is a phenomenon that occurs in which the minute area changes do not coincide with the area registered in the cadastral registration when the coordinate unit is changed. In this study, we have developed a method to adjust many parcels collectively by applying a passive fine-tuning method used in cadastral resurvey project to solve these problems. Total 1, total 2+1, interval 1, interval 2+1, etc. were classified based on the number of parcels that need to be considered for the range of adjustment and the area condition. The analysis of the experimental area (after developing SW for comparison of each method) showed that the total 2+1 method is suitable for the location accuracy and the interval 2+1 method is suitable for the temporal efficiency.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.393-398
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• 2007

According to the Korean datum change to a world geodetic system, the EDM area should be readjusted to provide consistent product over the country. The data set for EDM area is extracted from the previous KTN1987 DB and checked for the moved markers in XY network adjustment which provides quality verification. Then, EDM data set for the seven areas are rebuilt for the adjustment. Since the data is still based on the old datum, the coordinates of the data are transformed by applying the coordinate transformation parameters. Here, the transformation parameters, which were determined for the conversion of 1:50,000 topographic maps by NGII, were used. For each EDM point, the geoidal height from EGM96 model is applied to obtain the ellipsoidal height based on the GRS80. The measured distance projected onto GRS80 is adjusted using BL network adjustment by fixing 2nd order or 3rd order GPS control points. The results from the readjustment show the minimum standard error of 1.37" and the maximum standard error of 2.13". Considering the measurement accuracy of EDM (1.6" corresponding to about 2cm) and GPS position for fixed points (2cm), this result is considered to be reasonable and it is good for the practical use.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.241-247
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• 2012

The national geodetic reference frame of Korea switched to the International Terrestrial Reference Frame (ITRF) in 2003. In order to study the land area changes, we calculated the entire land area of Korea using the administrative boundaries of census data provided by Statistics Korea. The standard transformation procedure by the National Geographic Information Institute (NGII) was followed. The Transverse Mercator (TM) projected coordinates were transformed into the GRS80-based world geodetic reference frame, and the ellipsoidal and the projected areas were calculated. The provinces that range over two projection origins were divided into two polygons and projected using appropriate origins. After the transformation, all boundaries were shifted in the northwestern direction, resulting in a decreased area of $1.36km^2$ (about 0.0013%) on the projected plane. Moving the boundaries into a high latitude area cancels out the effect of the enlarged ellipsoid. In addition, the rate of change shows that a higher-latitude province is more sensitive to the shift of the boundaries. The data by Statistics Korea is significantly different from those of the Ministry of Land, Transport and Maritime Affairs (MLTM), thus it is urgently recommended that the data are integrated and unified.

• Journal of Cadastre & Land InformatiX
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• v.45 no.1
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• pp.151-167
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• 2015

At present cadastral surveying is being driven fort combination of digitalized cadastral map accord with real cadastral boundary between cadastral resurvey area and World Geodetic System transformation about all country. So this study is conducted to newly establish items being needed in making digitalization of parcel boundary points based on the World Geodetic System in registration conversion surveying. For this study firstly management of mountainous districts Act, related laws and registration conversion-related laws and regulations are reviewd. Secondly, economical, administrative validation by using data from 12-branch companies of LX is analyzed. Thirdly, surveying method and procedure were established through experimental surveying on the two cases such as digital and analog area. Finally, through investigating standard of estimate about cadastral surveying, it was calculated amendment of registration conversion surveying fee based on World Geodetic coordinate System.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.3-11
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• 2009

Open source is recently much more made and distributed by on-line such as internet in various fields. Therefore, end users could rapidly develop applications needed for some purposes using minimal efforts if use open sources. But, open source must be customized for their purposes. In this paper, we developed software for coordinates conversion and compared the software with NGI Pro which is developed by National Geographic Information Institute. Consequently, it is possible for us to easily develop the coordinates conversion module and we know that the use of open source is effective to develop various applications.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.315-324
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• 2022

The conventional LESS (LEast-Squares Solution) is calculated under the assumption that there is no errors in independent variables. However, the coordinates of a point, either from traditional ground surveying such as slant distances, horizontal and/or vertical angles, or GNSS (Global Navigation Satellite System) positioning, cannot be determined independently (and the components are correlated each other). Therefore, the TLS (Total Least Squares) adjustment should be applied for all applications related to the coordinates. Many approaches were suggested in order to solve this problem, resulting in equivalent solutions except some restrictions. In this study, we calculated the normal vector of the 3D plane determined by the trace of the VLBI targets based on TLS within GHM (Gauss-Helmert Model). Another numerical test was conducted for the estimation of the Helmert transformation parameters. Since the errors in the horizontal components are very small compared to the radius of the circle, the final estimates are almost identical. However, the estimated variance components are significantly reduced as well as show a different characteristic depending on the target location. The Helmert transformation parameters are estimated more precisely compared to the conventional LESS case. Furthermore, the residuals can be predicted on both reference frames with much smaller magnitude (in absolute sense).

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.3-7
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• 2004

Many countries have changed her geodetic reference system from local system to global system because of the global network's necessity. And, also Korean geodetic reference system changed from Tokyo datum to Global geodetic reference system since 2003 as the revision of Survey Law and Korean reference ellipsoid changed from Bessel 1841 ellipsoid to GRS80. The purpose of this paper is evaluation of ellipsoid agreement before and after change due to the introduction of global geodetic reference system in Korea. For the evaluation ellipsoid agreement was analyzed using two Korean geoid model -KOGD2003 and KOBGDM33- on both ellipsoid and area variation caused by change of reference ellipsoid was calculated.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1141-1151
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• 2007

In this paper through Honam high-speed railroad which is planned with the north and south axis, we will verify the feasibility of the coordinate conversion using railroad control points after regarding current planned-railroad as the linear central axises. From analysis, distortion of Y axis varies 21cm to 40cm diminishing to a gentle straight line, distortion of X axis varies 14cm to 29cm. Through a revision, the deviation value between the coordinates were 6mm to 9mm and it satisfied the allowable error of national geographic information institute which is following ITRF (International Terrestrial Reference Frame) and cadastral boundary survey(10cm). consequently the coordinate conversion is possible using railroad control points as common control points.