• Journal of Industrial Technology
• /
• v.36
• /
• pp.65-69
• /
• 2016

Deflection of the vertical is used in geodetic surveying associated with geoid network construction for geoid modeling and ellipsoid decision and obtained by gravity survey, astronomic survey etc. Technique of astronomic survey and gravity survey is very complex and requires a significant amount of time until gathering data. So this study is to determined a various method which evaluates deflection of the vertical and components about deflection of the vertical using GPS results and orthometric height value decided by leveling. Results of components about deflection of the vertical using GPS/leveling is that ${\xi}$ conponent is distributed $-2.11^{{\prime}{\prime}}{\pm}0.62$, ${\eta}$ component is distributed $1.75^{{\prime}{\prime}}{\pm}0.71$. Decision of component about deflection of the vertical using GPS is less complex than existing astronomic survey. Decision of component about deflection of vertical line using GPS is not complicated than astronomic surveying and can determine in a very short time. So it will be important means to determine the exact orthometric height, topographic study and diastrophism if can periodically calculate.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2007.04a
• /
• pp.17-20
• /
• 2007

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. Astronomic surveying has been regarded as an important method for absolute positioning of geodetic datum in each countries under the local geodetic reference system. This paper aims to analyses distribution of geoidal heights and ellipsoidal agreement between Bessel 1841 and GRS80 ellipsoid in Korea through comparing both astrogeotic geoidal heights referred to GRS80 and Bessel 1841 ellipsoid by astronomic surveying data which have been surveyed after 1970 in Korea.

• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.1 s.39
• /
• pp.47-53
• /
• 2007

Astronomic surveying has been regarded as an important method for absolute positioning of geodetic datum in each countries under the local geodetic reference system. The purposes of this study are to determine astrogeodetic geoidal heights referred to Bessel ellipsoid and to determine deflection of the vertical and geoidal heights referred to GRS80 of World Geodetic System by astronomic surveying data which have been surveyed after 1970 in Korea. The results show that $\xi$ component of the deflection of the vertical distribute from -5.725" to 8.005" and $\eta$ component distribute from -14.917" to 6.2" and astrogeodrtic geoidal heights distribute from 23 m to 27 m in the study area. Also, we could see that GRS80 was more optimal ellipsoid than Bessel 1841 ellipsoid to Korea through comparing both astrogeotic geoidal heights referred to GRS80 and Bessel 1841 ellipsoid.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.04a
• /
• pp.23-36
• /
• 2003

본 논문은 천문측량의 기본원리와 관측방법에 대하여 간단히 소개함과 동시에 국내에서 천문측량으로 실시된 국가경위도원점의 설치와 독도 천문측량 등 국내의 천문측량 현황에 대하여 체계적으로 고찰하였다. 그리고 재래식 천문측량의 단점이던 장비운용과 측량방법을 개선하여 디지털 천정카메라에 의한 천문측량의 자동화에 대한 외국의 사례를 소개하고 디지털 천문측량에 의한 연직선편차의 측정결과를 고찰하여 이의 활용방안을 논하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.4 no.1
• /
• pp.13-24
• /
• 1986

The objective of the present study is to establish the precision geodetic network in south Korea. The precision geodetic datum was determined based on the analysis and evaluation of the astronomic observation data observed by the National Geography Institute during the period of 1981∼1985. A proposal directions for the establishment of precision geodetic networks as well as review or analysis of current geodetic networks including the method of geodetic surveying in our country was completed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.1
• /
• pp.87-95
• /
• 1999

In this study, we investigated the methods of computing deflection of the vertical and compared the results of deflections of the vertical computed from astronomical coordinates and GPS observations, and computed from PNU95, EGM96 geoid model. By comparing the results of the deflections of the vertical, we found out the followings; 1) The deflections of the vertical computed from astronomical coordinates and geoid models are similar to each other. 2) The difference between the deflections of the vertical computed from each geoid models was smaller than the difference of those computed from astronomic coordinates and geoid models. 3) The effects of distribution of the points on the results are less than those of the data used in the computation. If there exists reference data about the deflection of the vertical, it would be possible to evaluate the accuracy of the geoid model using this method.