• 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.

• 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.30 no.6_1
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• pp.511-518
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• 2012

It is well-known that non-metric digital cameras have to be calibrated for the close-range photogrammetry. But, the self-calibration is still not an easy task because it requires rather a large calibration site of accurate control points, multiple image acquisitions in different positions, and accurate image point measurements that are quite labor-intensive and time-consuming. Based on the premise, this study carried out check point accuracy analysis from self-calibration of different control point designs and photo combinations. The test results showed that the calibration using three photos covering three-dimensional control points produced high accuracy, but control points on a plane could attain the comparable accuracy with four photos including a 90-degree rotated photo. We then compared the target accuracy of on-site self-calibration using flat control points to that of laboratory-self calibration and observed comparable results.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.3
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• pp.283-290
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• 2001

This paper demonstrates the performance of industrial precise measurement using the digital close-range photograrmmetric system based on a off-the-shelf CCTV-type CCD camera. The system was constructed with a CCD camera and a PC with a frame grabber, coupled with digital image mensuration and self-calibrating bundle adjustment techniques. An artificial fish reef with cubic shape was taken as an object for the application test of the system and the digital images were acquired on multi-station convergent network around the object. The geometric calibration of the CCD camera and the phototriangulation of the entire surface of the object was carried out simultaneously by means of self-calibrating bundle adjustment technique. Also the system comprising a high resolution still-video camera Kodak DCS, which high accuracy potential has been already established, were employed in similar network condition. Then the results from two different camera systems were compared in the accuracies of phototriangulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.2
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• pp.147-154
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• 2003

The close-range photogrammetry is a surveying technique the acquiring the 3D object from 2D geometric appearance shown in the image. Camera treatment is relatively so simple. Camera position refer to the object can be freely adjusted by locating the exposure station at any site. So it is used effectively on a small area or object for survey. In this study, using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D monitoring of high-accuracy in sub-pixel degree thorough digital close-range photogrammetry with bundle adjustment for local terrain model generation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.407-414
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• 2007

Even Korea is big country of automobile, the occurrence of traffic accident is in last place in 29 OECD countries. If it is evaluated by assessment guide of investment over the development project of public-traffic facilities, it was shown that the direct economical loss was fairly great. In this study, in order to minimize the traffic accidents occurring at curve area of road, it was tried to establish the standard of non-passing distance. The close-range photogrammetry was used and three dimensional modeling was fulfilled. Currently, this paper was focused on presenting the standard of road design with analyzing the internal and external standard of non-passing distance.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.55-64
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• 2005

This study demonstrates the experiment based on digital photogrammetric processing for acquiring data related to slope monitoring. To apply dose-range digital photos for monitoring road rock slopes, digital elevation models and digital orthophotos were generated and 3D modelling was conducted for the visualization on a digital photogrammetric workstation. These digital photogrammetric products can be utilized as objective and scientific data not only for surveying and analyzing the shape and characteristics of the slopes but also for extracting various engineering data for building the database of the slopes and making the safety diagnosis of the slopes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.365-371
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• 2003

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the techlique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D monitoring of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for local terrain model generation and 3D embodiment of tumulus. In the study is about to efficient analysis of digital information data fer conservation of cultural properties.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.3
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• pp.123-132
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• 2021

To determine 3D(three-dimensional) positions using a stereo-camera in close-range photogrammetry, camera calibration to determine not only the interior orientation parameters of each camera but also the relative orientation parameters between the cameras must be preceded. As time passes after performing camera calibration, in the case of non-metric cameras, the interior and relative orientation parameters may change due to internal instability or external factors. In this study, to evaluate the stability of the stereo-camera, not only the stability of two single cameras and a stereo-camera were analyzed, but also the three-dimensional position accuracy was evaluated using checkpoints. As a result of evaluating the stability of two single cameras through three camera calibration experiments over four months, the root mean square error was ±0.001mm, and the root mean square error of the stereo-camera was ±0.012mm ~ ±0.025mm, respectively. In addition, as the results of distance accuracy using the checkpoint were ±1mm, the interior and relative orientation parameters of the stereo-camera were considered stable over that period.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.561-568
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• 2011

The purpose of this study is to measure displacements that occurs on a surface and interior of slope model and the shape when the slope is destroyed at vibration experiment of the slope model using close range photogrammetry. The circle targets and sphere targets are installed on a chamber and a slope model, while the earthquake wave are applied in regular time interval. The close range photogrammetric images are acquired in each displacements step until the slope model is destroyed. Those photos are processed by image processing method and the center points of targets are automatically extracted. Furthermore, the three-dimensional coordinates of targets are calculated by image orientation and bundle adjustment processing. As a result, amount of displacement at each level is precisely measured and provided the basic information for assessing the slope stability using three-dimensional measurement of the target movement and slope destruction.