• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.3
• /
• pp.155-166
• /
• 2017

As the utilization of aerial images increases, a variety of software using unmanned aerial photogrammetric procedures as well as traditional aerial photogrammetric procedures are being provided. Previously, software that used the unmanned aerial photogrammetric procedure was used for images captured in small areas. Recently, however, software that uses unmanned aerial photogrammetric procedures for large-scale images taken by using aerial photogrammetric cameras has appeared. Therefore, this study generated ortho-images using aerial photogrammetry and unmanned aerial photogrammetry for large aerial images, and compared the features of both procedures through qualitative and quantitative comparisons. Experiments in the study area show that using the 3D mesh effectively removes the relief displacement of the building rather than using the digital surface model to generate ortho-images.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.14 no.1
• /
• pp.89-95
• /
• 1996

As an attempt to apply GPS technique to aerial photogrammetry, an effort is exerted to replace the ground control points that were necessary in the traditional aerial photogrammetry with the aerial control by measuring the position of the camera exposure. In this study, various situations are simulated to test the conditions that affect the positioning of the points in aerial photogrammetry for the use of GPS data. From the result of the simulations, the necessary conditions and the applicable values to produce a 1:1, 000 topographical map were suggested. In the case of a photo block consists of 104 photos, we found a minimum of six ground control points make acceptable accuracy under the condition of below $10\mu{m}$ image positional error and with the ground observations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.3
• /
• pp.337-345
• /
• 2010

In general, Digital Photogrammetry is based on independent workstation system, which is costly and has complex process. In this research, a new approach method regarding Digital Photogrammetry procedure is suggested using Web Processing Service, which is a GIS standard proposed by Open Geospatial Consortium. For the experiment, many Generic Processes were defined through WPS profiling procedure which defines standard unit for Photogrammetry, and with the defined process each server and client S/W module was implemented based on WPS standards. In this paper, many users can be expected to share and reuse unit process in WPS server through the web.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.4
• /
• pp.359-372
• /
• 1999

Recently, the digital map of national basemap has been made through NGIS(National Geographic Information System) project in Korea. The digital map should have to be corrected or updated to cope with the changes in topography in future. For that, the efficient method correspond with digital map should be presented. Digital photogrammetric system has been considered as an efficient method for digital mapping because it provides the results in digital form, but the system if not fully tested because the commercial system is in early stage. This study aims to present the way to correct or update digital map using the digital photogrammetric system. Digital mapping in the environment of digitalphotogrammetric system was executed and the results were analyzed and compared with those from analytical plotter.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2003.04a
• /
• pp.377-382
• /
• 2003

차량측량시스템이란 차량에 2대 이상의 CCD 카메라와 위치측정장비(GPS, IMU 등)를 장치하고 도로를 운행하면서 일정한 간격으로 주변의 사진을 연속으로 촬영한 후 이를 이용하여 도로 및 도로시설물의 위치와 크기, 보존상태 등의 정보를 취득하는 새로운 측량 시스템이다. 본 연구에서는 대상물의 3차원 위치결정을 위해 필요한 자료와 자료를 처리하는 각 단계를 체계화하였으며, 사용 편의성과 위치결정정확성을 높일 수 있는 차량측량시스템을 위한 수치사진측량 프로그램을 개발하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.22 no.3
• /
• pp.285-291
• /
• 2004

GPS photogrammetry or the GPS/INS photogrammetry, which are based on the direct measurement of the projection centers and attitude at the moment of camera exposure time through loading the GPS receiver or INS in aircraft. Both photogrammetric methods can offer us to acquire the exterior orientation parameters with only minimum ground control points, even the ground control process could be completely skipped. Consequently, we can drastically reduce the time and cost for the mapping process. In this thesis, test flight was conducted in Suwon area to evaluate the performance of accuracy and efficiency through the analysis of results among the three photogrammetric methods, that is, traditional photogrammetry, GPS photogrammetry and GPS/INS photogrammetry. Test results shows that a large variety of advantages of GPS photogrammetry and GPS/INS photogrammetry against traditional photogrammetry is to be verified. Especially, the number of ground control points for the exterior orientation could be saved more than 70～80%, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.4
• /
• pp.323-331
• /
• 2008

Digital close-range photogrammetric technique can measure and describe 3D geometric form from 2D image. This technique is a growing applicability in the field of sciences. Nevertheless, civil and mechanical field, which need measurements as precise as possible, use expensive measuring instruments in general. In addition there are occasions for analysis by means of visual method, since appropriate measuring instruments have been not yet available. This study therefore developed digital close-range photogrammetric technique with a movable orientation board to quickly measure deformation before and after destruction from simulated ground model of reinforced-soil wall. Then the results are compared with the measurements obtained using digital theodolite.

• Tunnel and Underground Space
• /
• v.21 no.1
• /
• pp.82-92
• /
• 2011

Stereophotogrammetry is used to extract spatial information of an object by constructing a stereo-image from two or more photos. In this study, stereophotogrammetry was adopted for analyzing blast fragmentation of rock blocks in a quarry site. 2D image processing and stereophotogrammetry were applied to the fragmentation analysis of rock blocks horizontally scattered in a laboratory, and their results were compared with physical measurements using a water tank. Fragmentation of rock muckpiles was estimated in laboratory and field tests by using the stereophotogrammetry and statistical analysis.

• Journal of the Korean Geophysical Society
• /
• v.9 no.2
• /
• pp.121-128
• /
• 2006

Recently, spillways are need to control stable water level for supporting main dams because of floods by unusual change of weather such as Typhoon Rusa. This study has been focused on the amount of leakage through the rock mass distributed fractures and joints under the opened emergency spillway. It is very important to evaluate the amount of leakage as these affect stability of spillway by interaction between effective stress and pore pressure. The commercial program MAFIC has been used for analyzing groundwater flow in fractured rock mass. The results showed that the values of range, average and deviation of leakage were 2.85∼ 3.79×10-1, 3.32×10-1 and 1.70×10-2 m3/day/m2 respectively. Secondary, we have estimated the effect of grouting after the transmissivity(Tf) of joint 1 as main pathway of leakage known from above results was changed from 1.78×10-7 to 1.59×10-9 m2/s. The results showed that the values of range, average and deviation of leakage were 7.80×10-4∼1.53×10-3, 1.18×10-3 and 1.32×10-4 m3/day/m2 respectively. As the result, the amount of leakage after grouting has been decreased by a ratio of 1 to 277.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.6 no.2
• /
• pp.34-41
• /
• 1988

Nowadays the considerable improvements, not only in photogrammetric equipment but also in adjustment methods have led to a high accuracy of Aerial Triangulation and reach the step to obtain A.T. technique that uses Global Position System without ground control survery. The enterance of analytical plotter have made considerable development both in accuracy and in efficiency and improved working environment of A.T. by the combination of On-Line Analytical Plotting System. In this paper, in A.T., with using of analytical polotter, aims to improve the acccuracy in coordinates determination of low level control point. The result shows that in case of A.T. with analytical plotter AVIOLYT BC2, the accuracy of control points improves to 7% in planimetry and to 40% in height compared to A.T. with precision plotter Autograph A-8.