• 한국지형공간정보학회:학술대회논문집
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• 2003.09a
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• pp.207-210
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• 2003

본 연구에서는 측량용 디지털 카메라인 Rollei사에서 제조한 d7 metric과 d7 $metrics^5$를 이용하여 촬영거리와 수렴각을 4m와 $30^{\circ}$로 일정하게 유지하고, 촬영방향을 다르게 하여 촬영하였으며, 또한 표정장업 시 일어나는 오차를 최소화 하기 위해 프로그램상에서 자동적으로 상호표정이 되는 원형타켓을 사용하였으며, 광속조정법을 실시하여 RMSE를 산출하였다. 이러한 연구는 근접사진측량으로 대상물을 측정할 시 촬영여건이 불가피하게 대상물의 중심방향에서 촬영이 어려울 경우 정확도를 평가하는데 이용될 것이라 사료된다.

• 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 Korean Tunnelling and Underground Space Association
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• v.18 no.6
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• pp.535-544
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• 2016

Special tunnel design and construction methods have been suggested due to developments of subway and tunnel. Collapse accidents of tunnel bring enormous damage. So, observation and analysis for the safety of tunnelling and behaviour of surrounding ground are important. But, it is not economical to implement the field test in every time. Therefore, this study has measured ground behaviour due to excavation of 2-arch tunnel station according to offset between grouped pile and tunnel by laboratory model test. For the model test, trapdoor device was adopted. Tunnelling is simulated by volume loss of 2-arch tunnel. Ground displacements are observed by close range photogrammetric method and image processing. In addition, these data are compared with numerical analysis.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.3-10
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• 2005

This study attempts to measure effectively three dimensional deformation in road slopes using digital close-range photographs. After the still video images were acquired respectively on the same multi-station geometric configuration in two epoches, photo-triangulation was rallied out respectively by conventional standard bundle adjustment and free-net bundle adjustment and the computed results were compared with those of geodetic method by total station. Three dimensional coordinates and deformation amounts were able to be derived with the RMSE of sub-millimeter and the relative accuracy of $1/30,000{\sim}1/35,000$. It was shown that free-net bundle adjustment is about 13% higher than standard bundle adjustment in the accuracy of photo-triangulation. It was ascertained that the free-net technique is able to promote fast and accurate deformation surveying without the necessity of geodetic control survey in complicated industrial sites.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.83-97
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• 2018

Tunnels are widely used for special purposes including roads, railways and culvert for power transmission, etc. Its cross-section shape is determined by uses, ground condition, environmental or economic factor. Many papers with respect to behaviours of adjacent ground and existing structure tunnelling-induced have been published by many researchers, but tunnel cross-section have rarely been considered. A collapse of tunnel causes vaster human and property damage than structures on the ground. Thus, it is very important to understand and analyse the relationship between behavoiurs of ground and cross-section type of tunnel. In this study, the behaviour of ground due to tunnel excavation for underground station below the grouped pile supported existing structure was analysed through laboratory model test using a trap-door device. Not only two cross-section types, 2-arch and box, as station for tunnel, but also, offset between tunnel and grouped pile centre (0.1B, 0.25B, 0.4B) are considered as variable of this study. In order to measure underground deformation tunnelling-induced, Close Range Photogrammetry technique was applied with laboratory model test, and results are compared to numerical analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.685-703
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• 2017

Recently, as the number of high-rise building and earthquake occurrence are increasing, it is more important to consider horizontal load such as wind and seismic loads, earth pressure, for the pile foundation. Also, development of underground space in urban areas is more demanded to meet various problem induced by growing population. Many studies on pile subjected to horizontal load have been conducted by many researchers. However, research regarding interactive behavior on pile subjected to horizontal load with tunnel are rare, so far. In this study, therefore, study on the behaviors of ground and horizontal and vertical loads applied to single pile was carried out using laboratory model test and numerical analysis. The pile axial force and ground deformation were investigated according to offset between pile and tunnel (0.0D, 1.0D, 2.0D: D = tunnel diameter). At the same time, close range photogrammetry was used to measure displacement of underground due to tunnelling during laboratory model test. The results from numerical analysis were compared to that from laboratory model test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.4
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• pp.87-94
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• 1990

In this study, the block adjustments are perfomed by bundle adjustment method of analytical photogrammetry, and the characteristics of 3-dimensional errors for the objects are analysed. The optimal arrangement and configuration of the control points is selected from various arrangements and configurations of control points, and the accuracies of result obtained by block adjustment and by single model adjustment are compared, And the accuracy of bundle block adjustment is compared with that of the independent model triangulation which is another method in block adjustment with additional parameters by selecting the suitable systematic error model. As a result of this study, an the effective method to improve accuracy in close-range photogrammetry was presented by forming blocks and using bundle block adjustment with proper arrangement and configuration of control poinst.

• Spatial Information Research
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• v.15 no.2
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• pp.169-180
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• 2007

Applicability of Land-based MMS(Mobile Mapping System) having been increased gradually as digitalization of administrative operation and construction of integrated systems of the government and provincial government are growing up. As these requirements, the case can be occurred that the facilities should be surveyed rapidly in the specific area. At this case, the real time field processing method is more necessary than the post processing method and data processing speed should be an essential element as important as accuracy. In this study, the two space intersection methods used in photogrammetry were programmed and compared with each other to select more proper method for the three dimensional positioning in the field processing. Especially, at the analytic space intersection, the traditional close range terrestrial photogrammetry was modified and applied to that to adapt to MMS's characteristics that camera position and attitude are changed according to the vehicle movement. As a result, the difference of the accuracy between two methods is not significant but at the calculation time, the analytic space intersection is faster three times than the space intersection using collinearity condition.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.228-233
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• 1998

This study presents a close-range photogrammetry that is applicable to beach profile estimation using a non-metric camera. Based on the analysis of oblique video image in which the video camera was installed on a horizontal plane and the field of view was fixed, a new equation to analyze a photograph was developed considering the following aspects: (1) camera is allowed to be rotated about its optical axis and (2) a simple error model is adopted to correct lens distortion and other systematic errors associated with the non-metric camera, which improves accuracy of non-metric imageries. To test the modified technique, photographs of the beach were taken near the Donghae City in February, 1998. In addition, beach profiles were surveyed with conventional dumpy level and surveying staff. RMS error between the estimated and measured beach profiles is less than 10 cm in elevation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.687-695
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• 2011

Many internet portals provide maps with spatial information services. Recently, various images including aerial, satellite, street view, and photo-realistic 3D city models are provided as well as maps. This study suggested a method for geometric correction of the panoramic aerial images in the internet portal and 3D building modeling using information which is available in the internet. The key of this study is to obtain all necessary data easily from internet without restrictions. Practically, the ground control coordinates could be available from geo-referenced internet maps, and stereo pairs of the aerial images and close-range photographs for photo-realistic object modeling are provided by the internet service. However, the ground control points are not suitable for accurate mapping. RMSE of the plotting was about 9 meters and reduced upto 4 meters after coordinate transformation. The proposed methods would be applicable to various applications of photo-realistic object modeling which do not require high accuracy.