• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2000.10a
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• pp.40-50
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• 2000

본 연구에서는 Rolleiflex 6006 측정용 카메라로 촬영된 사진과 DCS 420 디지털 카메라로부터 촬영된 화상을 이용, 수치근접사진측량을 실시한 후, 조경석의 표면 거칠기 측정 정확도 향상을 위하여 최소제곱법으로 기준평면 또는 기준곡면을 찾아 사용하는 방법을 연구하였으며, 조경석 표면의 연마 이전과 연마 이후의 표면 거칠기를 측정, 비교하여 연마후의 거칠기 감소크기를 산출하고, 측정 정확도를 알아보기 위하여 거칠기가 거의 없는 평면인 돌과 곡면인 돌의 표면 거칠기를 측정한 결과, 그 거칠기를 기대정확도 이상인 각각 $\pm$0.lmm 및 $\pm$0.2mm의 정확도로 측정할 수 있었다. 또한 측정용 카메라인 경우 렌즈왜곡 보정에 있어서 검정자료를 토대로 기준점을 사용하지 않는 직접보정방법인 Newton-Raphson법을 적용하여 기하학적 정확도가 향상된 수치사진화상을 얻을 수 있었으며, DCS 420 디지털 카메라와 윈도우 운영체계인 Visual basic 6.0을 이용하여, 표면 거칠기 측정시스템을 구축함으로써 연마이전 조경석과 연마이후 조경석에 대한 표면 거칠기 및 형상을 정밀 측정할 수 있는 수치근접사진측량기법을 제시할 수 있었다.

• 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

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.129-134
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• 2009

This study is on the development of photogrammetric methode for measuring the size of object without control points. The model is composed of interior orientation parameters, which are consist of specifications of CCD camera and lens distortion parameters, and exterior orientation parameters, which are calculated through relative orientation and scale adjustment. We evaluated the accuracy of the model to find that it is possible to measure the size of object using the model.

• 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.

• 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.31 no.2
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• pp.173-180
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• 2013

In this paper, we studied on measurement of soil deformation around the tip of model pile by close-range photogrammetry. The rigorous bundle adjustment method was utilized to monitor the soil deformation in the laboratory model pile-load test as function of incremental penetration of the pile. Control points were installed on the frame of the laboratory model box case and more than 150 target points were inserted inside the soil around the model pile and on the surface. Four overlapping images including three horizontal and one vertical image were acquired by a non-metric camera for each penetration step. The images were processed to automatically locate the control and target points in the images for the self-calibration and the bundle adjustment. During the bundle adjustment, the refraction index of the acrylic case of the laboratory model was accounted for accurate measurement. The experiment showed the proposed approach enabled the automated photogrammetric monitoring of soil deformation around the tip of model pile.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.1
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• pp.17-25
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• 1996

The development of still video CCD cameras has simplified dramatically the digital imaging process. Still video cameras have flexibility that allows digital image acquisition and on-board image storage without being connected to a computer. The objective of this paper is to evaluate the performance of digital close-range photogrammetric system using the still video camera for dimensional inspection and structural monitoring being required in various industries. Some sub-pixel measurement techniques, which is indispensable for digital image measurement, were suggested. The author carried out the self-calibration of a high resolution DCS420 still video camera and then test application of a structure. The self-calibrating bundle adjustments resulted in object space accuracies which exceed 1 :46,000. It is ascertained that this digital close-range photogrammetric system has high accuracy potential and task effectiveness for industrial applications.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.151-159
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• 1992

In close-range photogrammetry, to employ non-metric camera especially for the purpose of precise measurement, systematic errors must, first of all, be corrected as they have a great influence on accuracies of results. For it, fiducial marks was built in non-metric camera and the factors such as PPS, PPA, EFL, CFL, and radial lens distortion coefficients for each quadrant were calibrated through collimator test. Also, the coefficients of both radial and tangential lens distortion were calibrated from analytical plumb line method and therefore main systematic errors could be effectively corrected. Using the calibrated non-metric camera, close-range photogrammetry could be successfully accomplished and accuracies could be improved sharply.

• Journal of the Korean Geotechnical Society
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• v.24 no.2
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• pp.59-65
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• 2008

Digital close-range photogrammetric technique can measure and describe 3D geometric farm from 2D image. This technique is increasingly applied in the field of sciences. In the fields of civil and mechanical engineering, which need precise measurements for design, expensive measuring equipments are widely used. In occasions where visual inspection is required in addition to other forms of measurements, appropriate measuring equipments have not been yet available. This study utilizes digital close-range photogrammetric technique to quantitatively analyze behavior patterns before and after destruction from test model of reinforced-soil wall. Then the results are compared with the measurements obtained using digital theodolite to verify the reliability of the proposed method.