• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.2
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• pp.127-135
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• 2004

The calibration of lens to be used and the planning of photographing planning layout is very important to achieve the requested accuracy in the precision measurement by close-range photogrammetry. Establishment of absolute coordinate system is regarded as another important factor for the purpose of measuring absolute deformation of photogrammetric object. In this study, the following tasks were performed : (1) calibration of super-wide-angle lens or focal length 21mm fer close-range photographing used by 35mm metric camera, (2) development of the measuring system for monitoring of absolute deformation through periodic observation of small area, and, (3) application of this system to monitor the absolute deformation of surface of underwater structure in fixed cycle and to present the efficiency of the system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.1
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• pp.77-87
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• 1994

One of the often espoused merits of close-range photogrammetry is the effectiveness of the method for measuring non-accessible objects of unusual and complex shape. In this study, techniques of deformation measurement using close-range photogrammetry for electric power structures were developed. Absolute deformation could be found efficiently through close-range photogrammetry in the structure deformation analysis based on time variation. Also, feasibility of the structures management system was presented based on this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4D
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• pp.545-553
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• 2009

This paper describes the result of study on measurement of displacement of structure by means of non-contacting method, close-range digital photogrammetry using digital camera. To apply close-range digital photogrammetry to displacement measurement of structure, correction of lens distortion that interferes geometrical analysis has been carried out and then measuring displacement was performed on load regulated-rahmen. For enhanced applicability of displacement measurement, MIDAS which is a structural analysis program was used for modeling and the result was taken from comparative analysis. As a result of the study, it is showed that close-range digital photogrammetry could supplement several weaknesses of LVDT and cable displacement meter and, especially, economy in the perspective of measuring time could be realized. Close-range digital photogrammetry using digital camera can be applied to the area where requires visual analysis such as 3D modeling of structure, profile replication of measurement of structure as well as measurement of displacement of structure.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.217-223
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• 2015

In this paper, the performance of a system was analyzed according to the design parameters of a LED secondary lens that can be applied at a very close range, e.g., for direct lighting or display systems. We designed the secondary lens of the very-close-range LED using an aspheric equation and analyzed its performance-particularly the angle of the beam spread, central luminous intensity, and light uniformity-with respect to the thickness of lens, radius, conic constant, and asphericity (4th). Our analysis shows that four parameters affect the performance. The simulation results indicate an optimal thickness of 1 mm and show that a larger radius yields higher performance. The optimal range for the conic constant was determined as -1.21 to -1.25, the optimal range for the asphericity was determined as 0.0047xx to 0.0049xx (4th).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.5
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• pp.465-473
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• 2008

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.181-186
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• 2003

As the approach close-range digital photogrammetry has a variety of merits, the application of precision requiting fields is in Increase for its scope expansion. In the meantime, in case of photographic surveying by use of films, a lot of studies on experiment analysis and theoretical forecast models about a change of the exactness as per photographing coordinates have been conducted, but experiments about approach close-range digital photogrammetry are not enough yet. In consequence, this study has made photographing respectively by changing the photographic distance, converging angle, picturing direction by use of Rollei d7 metric and d7 metric$\^$5/ that is a measurement digital camera. And also in order to minimize the errors happened at the relative orientation, we have sorted out the prototype target that the relative orientation is automatically on the programming and have calculated RMSE by carrying out the bundle adjustment. We think that such a study could be used as very important basic data necessary in deriving the optimal photographic conditions by the close-range digital photogrammetry and in judging such a degree.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.95-106
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• 1995

The purpose of this study is to analyse the accuracy of non-metric photos by close-range photogrammetry. Close-range photogrammetry using non-metric photos is 'economical and convenient to handle, but it is insufficient of study on accuracy. To execute this study, first, the terrain model was made and then taken photographs of this model with metric and non-metric cameras. The Bundle adjustment and the Direct linear transformation methods are used for the analysis close-range photogrammetry. The results of the analysis showed that the Bundle adjustment method is a appropriate method for the analysis of the non-netric photo. Therefore, we concluded that the accuracy of the non-metric photo by close-range photogrammetry is applicability for the photogrammetry.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.251-260
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• 2005

The Development of CCD has contributed to great advancement in mapping technology with giving benefits to research community of photogrammetry. The purpose of this paper is to find the best selection of interpolation method for creating a terrain model form close range digital photogrammetry. T-test as a kind of statistical analysis was conducted to analyze the similarity of hydraulic model with close range digital photogrammetry and trigonometric leveling. Also, many interpolation methods such as inverse distance, kriging, nearest neighbor and TIN about the hydraulic model interpolation were conducted to compare the results for computer to display actual terrain an optimum interpolation of the digital elevation model form close range digital photogrammetry. The results revealed that kriging and TIN interpolation were efficient methods to judge the hazard interpolation law by analyzing geometric similarity of hydraulic model against hydraulic model application.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.211-215
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• 2010

This study is on the effective methods for non metric camera calibration for its use in accurate close range photogrammetric surveying. We tested four estimation methods used for calculating interior orientation parameters and two methods for building calibration field, one is using targets which have three dimensional coordinates and the other is using two dimensional grid targets. By analysing test results effective and accurate calibration methods were suggested.

• Journal of the Korean Geotechnical Society
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• v.26 no.8
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• pp.5-14
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• 2010

To simulate two-dimensional plane-strain conditions in the laboratory model test, the side frictional resistance between the soil and thick glass or plastic sheet of the soil container should be reduced as much as possible. However, in fact this side friction cannot be removed completely. In this paper, the ground model simulated as a multi-sized aluminium rod mixture was introduced to get rid of the side frictional resistance and applied to the laboratory shear box test. In addition, an application of the close range photogrammetric technique to the shear box test was validated. As a result, it was found that a mean value of dilation angle from the close range photogrammetry was close to the dilation angle defined by the curve of shear strain vs. volumetric strain.