• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.2
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• pp.123-129
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• 2003

This study analyzed and compared the results of baseline processing by Bernese GPS software packages and by GPSurvey software respectively. Then it investigated considerations when very long baselines are processed. There are rarely differences which is accompanied by baseline length when it is processed by Bernese GPS software but there are somewhat differences in proportion to the baseline length when it is processed by GPSurvey software.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.2
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• pp.131-142
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• 2015

In order to support the development of a cost-effective river bathymetric system, this research has focused on modeling GPS observables, which are obtained by array of five single-frequency receivers (i.e., two references and three rovers) to estimate the high accurate kinematic position, and the surveying vessel altitude. Also, by applying all GPS measurements as multiple-baselines with constraining rover baselines, we derived the socalled ‘kinematic network model.’ From the model, the integer-constrained least-squares (LS) for position estimation and the implicit LS for attitude determination were implemented, while a series of simulation tests with respect to the baseline lengths around 2km performed to demonstrate its accuracy analysis. The on-the-fly (OTF) ambiguity resolution tests revealed that ninety-nine percents of time-to-fix-first ambiguity (TTFF) can be decided in less than two seconds, when the positioning accuracy of ambiguity-fixed solutions was assessed as the greater than or equal to one and two centimeters in horizontal and vertical, respectively. Comparing to the GPS-derived attitudes, the achievable accuracy gradually descended in sequence of yaw, pitch and roll due to the antenna geometric configuration. Furthermore, the RMSE values for the baseline lengths of three to six meters were within ±1′for yaw, and less than ±10′and ±20′for pitch and roll, respectively, but those of between six to fifteen meters were less than ±1′for yaw, ±5′for pitch, and ±10′for roll.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.1 no.2
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• pp.42-59
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• 1983

This article investigates the situation of the Plane Rectangular Coordinate derived from the Gauss Double Projection whereby the positioning of triangulation point in Korea has been represented on. Analyzing and assessing it have been performed by means of new computational method such as computer programing. On the basis of the results brought about, it is found that a new Plane Rectangular Coordinate as well as map projection and scale factor of geodetic length may be adapted to improve the distortion along the geodetic line on a certain zone of map projection in order to enhance the accuracy and the utility of the practical surveying works. The proposals for this study are as follows; (1) projection: Gauss-Kruger's projection (2) Coordinate system: Plane Rectangular coordinate with 8 origin system (3) Scale factor of geodetic length in origin; $m_0=0.9999$

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.613-620
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• 2011

In order to perform scientific evaluation of dredge results, it is needed to construct the system which is able to manage and evaluate the work process by monitoring in real-time the dredge process such as dredge ship position, dredge depth and dredge volume. This research aims to develop the hydrographic dredge surveying system adding water depth measurement method to both precise positioning and navigation methods using GPS, which allows a high rate of measurement and long distances between the control point and dredging points, operate in all weather conditions, and does not require line of sight to points. We constructed Beacon DGPS-based hydrographic dredger guidance and position management system and developed the operation program which makes the dredge operation perform as monitoring work situation in real-time. It is expected that this developed system will be able to contributes to reducing ultimately the cost in hydrographic dredging or hydrographic construction industries.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.129-134
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• 2003

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.121-127
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• 2002

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.351-354
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• 2002

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2001.10a
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• pp.97-102
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• 2001

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.243-250
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• 1998

From early plane-table photogrammetry through the analog and analytical stages, photogrammetry has now reached the digital photogrammetry stage using the image stored at computers. Digital Photogrammetry using aerial photograph generates the DTM and digital orthophoto. Expecially, DTM is important for improving the accuracy of digital ortho photo. so Many experimental are required. In this study, therefore deals with the generation process of digital orthophotos using DTM with breakline and without breakline.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.187-194
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• 2002

본 논문에서는 SPOT 입체영상을 이용하여 광범위한 지역의 DEM을 제작할 경우 DEM 모자이크 과정에서 발생할 수 있는 접합선(seam-line)을 최소화할 수 있는 방법을 연구하였다. 지상의 60km$\times$60km 영역을 촬영할 수 있는 SPOT 위성의 입체 영상으로부터 구성한 단일 모델은 일반적으로 관심 있는 지역의 DEM을 제작하기에 충분히 넓은 지역을 포함할 수 있다. 그러나 광범위한 지역의 DEM 제작을 위해서는, 각각의 입체영상을 통해 제작된 DEM들을 접합해야 하며, 이 때 발생되는 접합선을 효과적으로 제거하는 작업이 필요하다. 이를 위해 SPOT 위성영상의 블록 조정 방법을 이용하여 종횡접합모델을 구성하고 중복되는 인접한 SPOT DEM간의 표고값을 일치시키므로써 DEM 접합선의 발생을 최소화하여 모자이크시 작업량을 줄이고자 한다. 본 논문에서는 기존의 지상기준점과 추가로 관측한 영상접합점을 이용하여 종횡접합 블록을 구성하고 광속조정 방법을 적용하여 블록에 포함된 위성영상의 외부표정요소를 계산하였다. 블록모델을 이용하여 DEM을 제작할 경우 접합선 탐색 및 blending 작업 없이 단순중첩 방법으로도 DEM 모자이크 작업을 빠르게 수행할 수 있음을 확인하였다.