• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.51.3-51.3
• /
• 2015

1995년 한국 최초로 VLBI관측이 이루어졌다. 일본 측의 26m 안테나(일본 국토연구원 소재)와 한국 측의 3.6m 안테나(국토지리정보원 소재)로 수행되었으며, 이 때 결정된 관측점의 좌표가 세계 공통으로 사용되는 "세계측지계(ITRF)"에 의거한 새로운 국가기준좌표계의 경위도 원점이다. 그 후 측지VLBI관측국의 설치를 위해, "측지VLBI구축 타당성조사 및 기본계획 수립을 위한 연구(2003년)"와 "측지VLBI구축 실시설계(2006년)"를 수행하였다. 그 결과 국가 차원에서 측지VLBI관측소(22m 안테나)를 건설하기 위해 2008년에 관측소 후보지를 세종시로 확정해서 공사에 들어갔다. 2012년에 준공되었으며, 명칭을 "우주측지관측센터"로 하였다. 그 후 1년 동안의 시험관측의 성공으로 아시아에서 3번째로 정식으로 IVS(International VLBI Service)에 가입하였다. 현재 독일, 일본, 미국 등의 측지VLBI관측국들과 정기적으로 관측을 수행하게 되었으며, 실적을 올리고 있다. IVS사업 뿐 만 아니라, 한국천문연구원의 KVN(천문 VLBI)연구팀과도 공동연구를 수행해서 우리나라의 천문 VLBI 및 측지VLBI관측사업의 활성화에 기여하고 있다. 장차 동남아 각국에 마이크로SAR위성의 관측데이터를 수신하기 위한 지상국(3m급 소형안테나)이 설치되면, 이를 활용해서 측지VLBI관측을 수행할 계획을 수립하고 있다. 이것은 위성용 수신기를 VLBI용 수신기로 교체하면 된다. 한국과 일본이 VLBI관측을 수행했던 것처럼 세종시에 설치된 우주측지관측소가 허브역할을 하면 된다. 즉 동남아 지역에 우주 VLBI관측망을 구축하게 된다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2006.04a
• /
• pp.59-63
• /
• 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
• /
• v.27 no.2
• /
• pp.169-175
• /
• 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
• /
• v.13 no.2
• /
• pp.117-124
• /
• 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 Society for Railway
• /
• v.10 no.6
• /
• pp.685-691
• /
• 2007

In this paper through Honan 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 21 cm to 40 cm diminishing to a gentle straight line, distortion of X axis varies 14 cm to 29 cm. Through a revision, the deviation value between the coordinates were 6 mm to 9 mm and it satisfied the allowable error of national geographic information institute which is following ITRF (International Terrestrial Reference Frame) and cadastral boundary survey (10 cm). consequently the coordinate conversion is possible using railroad control points as common control points.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.6_2
• /
• pp.613-623
• /
• 2007

The main purpose of this study is to investigate the coordinate transformation based on two different systems between local geodetic datum(tokyo datum) and international geocentric datum(new Korea geodetic datum). For this purpose, three methods were used to determine seven parameters as follows: Bursa-Wolf model, Molodensky-Badekas model, and Veis model. Also, we adopted multiple regression equation method to convert from Tokyo datum to KTRF. We used 935 control points as a common points and applied gross error analysis for detecting the outlier among those control points. The coordinate transformation was carried out using similarity transformation applied the obtained seven parameters and the precision of transformed coordinate was evaluated about 9,917 third or forth order control points. From these results, it was found that Bursa-Wolf model and Molodensky-Badekas model are more suitable than other for the determination of transformation parameters in Korea. And, transforming accuracy using MRE is lower than other similarity transformation model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.3
• /
• pp.241-247
• /
• 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 the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.3
• /
• pp.273-282
• /
• 2005

A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF (International Terrain Reference Frame). Currently the National Geographic Information Institute (NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

• Journal of Korean Society for Geospatial Information Science
• /
• v.14 no.1 s.35
• /
• pp.65-74
• /
• 2006

A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF(International Terrain Reference Frame). Currently the National Geographic Information Institute(NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

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