• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.91-97
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• 2004

As for the former analogue method of photogrammetry, We have obtained final digital drawing by creating the stereo model from overlapped images through orientation process using plotting instrument and processing restitution procedure. However, digital photogrammetry batch processes such using small computer system thus We make an attempt automatization of the procedures. And without the production of stereo model, We could obtain 3D digital data through analysis method. Therefore, an objective of this study was to implement a surveying system that could 3D surveying positions using the digital image to reduce limitations of control point surveying and photographing conditions more efficiently to produce digital drawing. By the result, photogrammetry can practice and make out digital drawing to a computer by digital camera of a comparative low-cost. Small scale area can become practical use to drawing production etc. for facilities management because area can make out digital drawing economically than general surveying.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.45-58
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• 1998

Digital photogrammetry is growing today using inexpensive personal confuter and digital image Processing technique instead of expensive analytical plotter in data acquisition from aerial photograph. Ortho photo in replacement of paper map is indispensable in the application of Geo-Spatial Information System and research activities about it are active in the domestic domain. Also the availability of ortho photo is greatly various in existing related fields using topographic map and expected to be used for new technology in near future. For this purpose, design of each module for ortho photo has been carried out with digital map and image. It was shown that the batch program for ortho photo generation developed in this study, could be used effectively as an effective data acquisition method for GSIS.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.91-99
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• 2009

In the field of geospatial information, 3D shape information has been considered as a frame data for GIS. Many kind of physical shape information is, especially, required for the works related with space, such as planning, maintenance, management, etc. Conventional photogrammetry was implemented under the conditions with expensive metric cameras and analytical plotters operated by experts. Nowadays, however, the metric cameras and analytical plotters are replaced by low price non-metric digital cameras and personal computers by virtue of the progress in digital photogrammetry. This study aims to investigate the technology to easily and promptly produce 3D shape information required in geospatial information system using close-range photogrammetry with non-metric digital cameras. As the results of this study, 3D shape of an experimental object was made out with a common compact digital camera and only a known length of a line component in the object and the accuracy of the dimension of 3D shape was analyzed to be less than one pixel.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.10 no.2
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• pp.25-30
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• 1992

Most algorithms in computer vision and digital photogrammetry assume that digital stereo pairs are registered in epipolar geometry. But, an aerial stereo pair is not likely to be in epiplar geometry since the attitude of the camera at the instant of exposure is different at every exposure station. In this paper, stereo digital imagery is obtained from aerial stereo pair by scanner. Then procesure to resample the digital imagery to epipolar geometry using exterior orientation elements after absolute orientation is described. As a result, a stereo imagery in epipolar geometry is produced from stereo digital imagery. Epipolar imagery in this paper is applied to the image matching method by digital image correlation technique. Then, a digital elevation model is produced from the result of image matching. The digital elevation model in this paper is compared to the other digital elevation model produced by analytical plotter. As a result, an economical method to generate digital elevation model is presented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.9-18
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• 1991

A diagram has been annexed to the spot inspection record of the traffic accident were drawn up with measuring-tape heretofor. However, conventional reduction method have been usually contained the various problems according to the social development. To solve these problems, it was performed that photogrammetric method are measured 3-D coordinate of needed points and precised plotting of traffic accident spot investigation. Also, they have produced some good effects on speedy spot investigation and settlement of traffic stagnation. Because semi-metric camera and MR2 system are utilize for low cost, simple operation and almost unnecessary for control point surveying, these fittings being at the close-range photogrammetry will be extremely powerful over versatile fields like traffic accident in police.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.277-284
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• 2004

The subject of this study is to apply experimentally In resolution stereo imagery of IKONOS to producing 1:50,000 scale maps for Munsan area in Paju, being near the Military Demarcation Line, is inaccessible for aerial photography. Ground control points were acquired from GPS surveying to perform geometric corrections on images. Digital maps were produced from IKONOS stereo imagery on the digital photographic workstation. From field investigation, RMS errors of the plane and vertical positions are estimated respectively at $\pm$1.706m and $\pm$1.231m, respectively. These plane and vertical accuracies are within the tolerance limits of those provided in the NGIS Digital Topographic Map Production Rules. Therefore this suggested method is recommended for producing the large scale digital maps of 'No flight' zone near the M.D.L.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.3
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• pp.137-149
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• 2021

Cable-stayed bridges are infrastructure facilities of a highly public nature; therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage caused by natural and social disasters. Among social disasters, impact accidents can occur in bridges when a vehicle collides with a pier or when crashes occur due to aircraft defects. In the case of offshore bridges, ship collisions will occur at the bottom of the pylon. In this research, a procedure to evaluate the structural behavior of a cable-stayed bridge for aircraft impact is suggested based on a numerical analysis approach, and the feasibility of the procedure is demonstrated by performing an example assessment. The suggested procedure includes 1) setting up suitable aircraft impact hazard scenarios, 2) structural modeling considering the complex behavior mechanisms of cable-stayed bridges, and 3) structural behavior evaluation of cable-stayed bridges using numerical impact simulation. It was observed that the scenario set in this study did not significantly affect the target bridge. However, if impact analysis is performed through various scenarios in the future, the load position and critical load level to cause serious damage to the bridge could be identified. The scenario-based assessment process employed in this study is expected to facilitate the evaluation of bridge structures under aircraft impact in both existing bridges and future designs.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.77-87
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• 2004

It is important for hydrographers to extract the accurate cross section of a river for the hydrographical analysis of the topography. Aerial photographs were used to extract the cross section of a river for the advantages of the accuracy and economical efficiency in this study, while the direct measurement has been used in existing studies. An ortho-rectified photo map using imageries taken by the PKNU 2 (High-resolution, multi-spectral, aerial photographic system developed by our laboratory) was generated using the surveyed data and a digital map. The cross section of a river that was obtained from the ortho-rectified by the surveyed Kinematic data of GPS was compared with the result using ImageStation stereo-plotter of corp. Z/I Imaging. As a result of this study, the RMSE in the ortho-rect process using the surveyed GPS data was lowered as from 5.5788 pixels (about 2m) to 2.84 (about 1m) in comparison with it in the process using a digital map. The surveyed kinematic GPS in extraction of the cross section of a river was excellent as 6.6cm of the planimetric and precision in the confidence level of 95%. The correlation coefficient between the result from the using stereo-plotter and the extraction of cross section of a river using aerial photos was 0.8 hydrographical acquisition of it using PKNU 2 imagery will be possible.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.1-8
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• 2001

Conventional microgyroscopes of vibrating type require resonant frequency tuning of the driving and sensing modes to achieve high sensitivity. These tuning conditions depend on each fabricated microgyroscopes, even though the microgyroscopes are identically designed. A new micromachined resonator, which is applicable to microgyroscopes with self-toning characteristics, is presented. Since the laterally driven two degrees of freedom (2DOF) resonator was designed as a symmetric structure with identical stiffness in two orthogonal axes, the resonator is applicable to vibrating microgyroscopes, which do not need mode tuning. A dynamic model of the resonator was derived considering gyroscopic application. The dynamic model was evaluated by experimental comparison with fabricated resonators. The microgyroscopes were fabricated using a simple 2-mask-process of a single polysilicon layer deposited on an insulator layer. The feasibility of the resonator as a vibrating microgyroscopes with self-tuning capability is discussed. The fabricated resonators of a particular design have process-induced non-uniformities that cause different resonant frequencies. For several resonators, the standard deviations of the driving and sensing frequencies were as high as 1232Hz and 1214Hz, whereas the experimental average detuning frequency was 91.75Hz. The minimum detuned frequency was 68Hz with $0.034mVsec/^{\circ}$ sensitivity. The sensitivity of the microgyroscopes was low due to process-induced non-uniformity; the angular rate bandwidth, however, was wide. This resonator could be successfully applicable to a vibrating microgyroscopes with high sensitivity, if improvements in uniformity of the fabrication process are achieved. Further developments in improved integrated circuits are expected to lower the noise level even more.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.97-105
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• 1997

In order to conserve architecture accurately as original feature, we need to get the data which is measured in detail about the information of size, position, type, shape, and other terms for architectures. Recently, we need to get data fast and correctly, to compose and to update the database of geographic information system, but using existing method. it is difficult to update the data effectively in the rapid development of information industry. In this study, therefore, It is measured precisely architecture using accurate close-range photogrammetry The aims of this study are real-measured plan by processing acquired image through multi-image matching method if photogrammetry, suggesting the method which is able to draw in detail front plane and plane of well-established architecture, and giving data to obtain accurate size and 3-D coordinate using analytical method.