• Journal of Korean Society for Geospatial Information Science
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• v.8 no.2 s.16
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• pp.89-99
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• 2000

The Quality and Accuracy of digital image is important factor for decision of accuracy in digital photogrammetry because all the inside works in digital photogrammetry are based on digital image. But it is still difficult to ensure quality assurance and appication of data because there is no distinct criterion about quality and accuracy of digital image when the works in digital photogrammetry is accomplished. This study presents optimal resolution of aerial photo through error analysis of image coordinate using auto inner orientation in digital photograrnrnetry workstation. In second step, we are valified to optimum resolution of aerial photo image with orientation analysis. Finally, we are established to validity optimal resolution of aerial photo image with production of ortho image and mosaic image using optimal resolution aerial photo image.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.37-44
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• 2006

To use surveying data obtained from different sensors and different techniques, it is a pre-requite step that register them in a common coordinate system. For this purpose, we developed methodologies to register airborne photos, ALS (Airborne Laser Scanning) data and digital maps. To achieve this, conjugate features from these data should be extracted in advance. In this study, linear features are chosen as conjugate features. Based on such a selection strategy, a simple and robust algorithm is proposed for extracting such features from ALS data. Then, to register them, observation equations are established from similarity measurements of the extracted features and the results was evaluated statistically. The results clearly demonstrate that the proposed algorithms are appropriate to register these data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.4
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• pp.267-277
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• 2019

Photogrammetry and computer vision are identical in determining the three-dimensional coordinates of images taken with a camera, but the two fields are not directly compatible with each other due to differences in camera lens distortion modeling methods and camera coordinate systems. In general, data processing of drone images is performed by bundle block adjustments using computer vision-based software, and then the plotting of the image is performed by photogrammetry-based software for mapping. In this case, we are faced with the problem of converting the model of camera lens distortions into the formula used in photogrammetry. Therefore, this study described the differences between the coordinate systems and lens distortion models used in photogrammetry and computer vision, and proposed a methodology for converting them. In order to verify the conversion formula of the camera lens distortion models, first, lens distortions were added to the virtual coordinates without lens distortions by using the computer vision-based lens distortion models. Then, the distortion coefficients were determined using photogrammetry-based lens distortion models, and the lens distortions were removed from the photo coordinates and compared with the virtual coordinates without the original distortions. The results showed that the root mean square distance was good within 0.5 pixels. In addition, epipolar images were generated to determine the accuracy by applying lens distortion coefficients for photogrammetry. The calculated root mean square error of y-parallax was found to be within 0.3 pixels.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.4 s.27
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• pp.3-11
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• 2003

Lately, digital photogrammetry based on the principles of photographic suey has been more and more applied to various high-tech industries and becomes one of more interesting focuses of study than ever. Thus, this study aims to develop a roadway information system by means of digital photogrammetry. Data acquired from digital photogrammetry were processed via Delphi, an object-oriented programming language to develop a computer aided program that allows us to build up the information on road horizontal alignment(BC, EC, R. IP), road vertical alignment and road facilities. And the developed program could maximize the visual effects better than traditional programs, because it used many image data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.8 no.1
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• pp.31-40
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• 1990

In this study, sample area was selected to compare the conventional method with photogrammetic method in basic planning of country club. Also various elements of planning, such as vegetation and water system, were considered through interpretation of aerial photographs and topographic maps, vegetation maps and water system maps were made as well as digital terrain models. These were used to analyse tophographic changes and landscape. As a result of comparing with the conventional method, it was shown that photographic interpretation could give more detail values than the conventional method, and that the digital terrain model could predict changes of topography, landscape and water system with more asccuracy. Consequently, the method of digital terrain model and photographic interpretation proved to be more effective than the conventional method in the case of water treatment, and planning of landscape and land utility.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.2
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• pp.63-68
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• 1989

This study was to develope the methmatic prediction model of accuracy for the convergent photographs using nonmetric camera in close range photogrammetry. By analyzing positioning error on object distance and convergent angles, the validity of the new formulae for prediction of accuracy were proved. Rational design of camera systems and convergent angles according to accuracy demands in plane and height were developed using these formulae.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.1
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• pp.69-76
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• 2005

The purpose of this study was to establish the accuracy of the industrial photogrammetry system constructed with INCA2 metric camera and V-STARS system on steel box girder measurement under industrial measurement condition. The objective of the measurement was to determine the distances of plane to plane or plane to libs, precise positions of the bolt holes and angles of the plane to plane on the steel box girder using coded targets, tape targets, edge targets and target adapters. The measurement undertaken has shown that industrial photogrammetry method were a very accurate and more importantly were produced quickly to measure the steel box girder.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.147-154
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• 2001

The development of equipments which are for the collection and processing of digital images in digital photogrammetry is actively performed at the research about practical use. The close-range digital photogrammetry is widely using to determine accurate position, feature, and size of objects. The goal of this study is to judge the precise surveying possibility of a streamline object, like a vehicle, using digital close-range photogrammetry. The standard deviation of the calculated coordinates is respectively ${\sigma}_x$=0.434mm, ${\sigma}_y$=0.619mm, ${\sigma}_z$=0.387mm. The result values is enough to converge an accuracy required for the field of an automobile design. Therefor we suggest that the digital close-range photogrammetry could be use for the majority of industries.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.209-215
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• 2004

Together with the requirements of tunnels, its construction methods and technologies have been pretty much developed, but frequent accidents happened under the constructions are just one of important problems which should be improved. To detect the potential hazardous factors in or ahead of time, speedy and accurate observation are absolutely required, but currently surveying method using tapes, level and total station, has been generally taken in measuring of tunnel convergence and crown. The purpose of this study is, as using of industrial photogrammetry system which is supplying more accuracy and speedy in the measure of tunnel convergence and crown. From the result of this study, we have got up to 1/20,000 accuracy and totally 6 minutes, from picturing 5 sections by one person to data edition, has been taken except setting targets.

• 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.