• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.1
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• pp.41-46
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• 2021

As data acquisition using unmanned aerial vehicles is widely used, as one of the ways to increase the accuracy of photogrammetry using unmanned aerial vehicles, a method of inputting both vertical and oblique images in bundle adjustment of aerial triangulation has been proposed. In this study, in order to find a suitable method for increasing the accuracy of photogrammetry, the accuracy of the case of adjusting the oblique images taken at different shooting angles and the case of adjusting the oblique images with different shooting angles at the same time with the vertical images were compared. As a result of the study, it was found that the error of the checkpoint decreases as the angle of the input oblique images increases. In particular, when the vertical images and oblique images are used together, the height error decreases significantly as the angle of the oblique images increases. The current 『Aerial Photogrammetry Work Regulation』 requires RMSE (Root Mean Square Error), which is the same as GSD (Ground Spatial Distance) of a vertical image. When using an oblique images with a shooting angle of 50°, a result close to this standard is obtained. If the vertical images and the 50° oblique images were adjusted at the same time, the work regulations could be satisfied. Using the results of this study, it is expected that photogrammetry using low-cost cameras mounted on unmanned aerial vehicles will become more active.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.78-82
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• 2009

최근 국내에는 다차원 공간정보 구축을 위하여 디지털 항공사진 및 항공라이다 장비를 이용하고 있으나, 위 데이터만을 이용하여 세밀하고 사실감 있는 3차원 공간데이터를 구축하는데 제한적이며, 고품질의 Texture Mapping을 위해 지상사진을 이용하지만 인력 및 작업 시간이 많이 소요된다. 이에 해외에서는 사실감 있는 3차원 공간정보 구축을 위하여 연직과 경사사진을 동시에 촬영하는 다각사진촬영시스템을 이용하고 있으며, 본 연구에서는 다각사진촬영시스템 개발시 고려해야할 경사사진 촬영 설계요소에 대하여 분석하였다. 연구결과 촬영고도, 카메라각도에 의하여 경사사진 주점의 거리, 지상해상도, 카메라 화각(FOV), 촬영영역에 대하여 분석할 수 있었다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.369-375
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• 2010

Since multi-view images can be utilized for 3D visualization and surveying as well, a system calibration is an essential procedure. The cameras in the system are mounted to the holder and their locations and attitudes are relatively fixed. Therefore, the locations and the attitudes of the perspective centers of the four oblique looking cameras can be calculated using the location and attitude of the nadir looking camera and the boresight values between the cameras. In this regard, this research is focusing on the analysis of the relative location and attitude between the nadir and oblique looking cameras based on the results of the exterior orientation parameters after the aerial triangulation of the real multiview images. We acquired high standard deviations of the relative locations between the nadir and oblique cameras. Standard deviations of the relative attitudes between the cameras were low when only the exterior orientations of the oblique looking cameras were allowed to be adjusted. Moreover, low standard deviations of the relative attitudes came when we considered not all the exterior orientations of the cameras but the attitudes of them only.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.143-150
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• 1984

This paper is a study on effectiveness of weight in analytical positioning of oblique photography. Oblique photographies are more economical than normal photographies as it has a larger ground coverage and as it can be applied in situations where objects of interest are difficult to be approached. But the comparatively complex methods involved, present a problem in obtaining the desired results. In view of this fact, analytical rectification was applied in normalizing the oblique photographs. As oblique photographies are extensively used in slops and mountainous regions, a number of difficulties are encountered during the control surveying. The photocoordinates of the oblique photographs, taken at $30^{\circ}$, were weighted during rectification. They were weighted as inversely proportionate to the derived formular of ${\gamma}_y=f{\cdot}tan{\frac{\theta}{2}}+y_a$, the distance of each point from the isocenter along the Y axis. By applying the weights, coordinates errors conld be reduced and the error difference between oblique and normal photographs could be reduced upto 53.2%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.1
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• pp.137-144
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• 1984

In comparison to normal photography, oblique photography has large coverage area and is easily applicable to objects which are difficult to approach. But it has its deficiency of having to go through complex procedures of rectification. Oblique photographs are first analytically rectified, in this paper, then the coordinates of facilities are analysed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.351-357
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• 2008

An aerial multi-looking camera system equips itself with five separate cameras which enables acquiring one vertical image and four oblique images at the same time. This provides diverse information about the site compared to aerial photographs vertically. The geometric relationship of oblique cameras and a vertical camera can be modelled by 6 exterior orientation parameters. Once the relationship between the vertical camera and each oblique camera is determined, the exterior orientation parameters of the oblique images can be calculated by the exterior orientation parameters of the vertical image. In order to examine the exterior orientation of both a vertical camera and each oblique cameras in the multi-looking camera relatively, calibration targets were installed in a lab and 14 images were taken from three image stations by tilting and rotating a non-metric digital camera. The interior orientation parameters of the camera and the exterior orientation parameters of the images were estimated. The exterior orientation parameters of the oblique image with respect to the vertical image were calculated relatively by the exterior orientation parameters of the images and error propagation of the orientation angles and the position of the projection center was examined.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.114-124
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• 2007

Objective: The purpose of this study was to examine how the mesio-distal angulation and the length of each tooth changes on panoramic radiograph at different bucco-lingual inclinations. Methods: After constructing an acrylic model based on the mean arch of 30 adults with normal occlusion, the wire was placed in the center of the teeth on the acrylic model. First, the wire was implanted in normal angulation and inclination and a panoramic radiograph taken. After changing the inclination from $I-5^{\circ}\;to\;I+15^{\circ}\;by\;5^{\circ}$, a panoramic radiograph was taken again and the mesio-distal angle and wire length on the panoramic radiograph were assessed. Results: When the wire was implanted at the normal angulation and inclination, the length measured in the panoramic radiograph was magnified $111{\sim}117%$ from the original length in the anterior region and $121{\sim}125%$ in the posterior region. Only the central and lateral incisors showed significant length differences when the inclination was changed from $l-15^{\circ}\;to\;I+15^{\circ}$ at fixed angulation. When the inclination was changed from $l-15^{\circ}\;to\;I+15^{\circ}$, the angulation of most teeth on panoramic radiograph appeared to be more disto-angulated than in reality, and the lateral incisor and canine showed the largest difference. Only $l-15^{\circ}\;to\;I+15^{\circ}$ groups of premolars and $I+15^{\circ}$ group of molars showed more mesio-angulation than in reality. As the labio(bucco)lingual inclination of all teeth were decreased, tooth angulation in the panoramic radiograph appeared to be more disto-angulated. Conclusion: The labio-liugual inclination of teeth should be considered because it affects panoramic image of teeth, such as length of incisors and angulation of other teeth.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.261-271
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• 2009

Due to the recent rise of a need for 3 dimensional geospatial information on urban areas, general interest in aerial multi-view cameras has been on an increase. The conventional geospatial information system depends solely upon vertical images, while the multi-view camera is capable of taking both vertical and oblique images taken from multiple directions, thus making it easier for the user to interpret the object. Through our research we developed a prototype of a multi-view camera system that includes a camera system, GPS/INS, a flight management system, and a control system. We also studied and experimented with the camera viewing angles, the synchronization of image capture, the exposure delay, the data storage that must be considered for the development of the multi-view camera system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.129-135
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• 1983

During engineering projects, land use and geologic investigations, topographic information by means of Photointerpretation and Photographic Survey often plays an important role. As some recent methods of Dip and Strike determination were used without considering the characteristics of the geometrical conditions of photography, it is necessary to present an accurate and rapid formula. In this paper, Dip and Strike determination using photogrammetric method was theoretically approached with geometrical and mathematical models using trigonometric formula and plane equation, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.145-154
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• 2014

The road network becomes more complex and extensive. Therefore, the inconveniences are caused in accordance with the time delay of the restoration of damaged roads, demands for excessive costs on information collection, and limitations on acquisition of damage information of the roads. Recently, road centric spatial information is gathered using mobile multi sensor system for road inventory. But expensive MMS(Mobile Mapping System) equipments require high maintenance costs from beginning and takes a lot of time in the data processing. So research is needed for continuous maintenance by collecting and displaying the damaged information on a digital map using low cost mobile camera system. In this research we aim to develop the techniques for mosaic with a regular ground sample distance using successive image from oblique camera on a vehicle. For doing this, mosaic image is generated by estimating the homography of high resolution oblique image, and the ground sample distance and appropriate overlap are analyzed using high resolution aerial oblique images which contain resolution target. Based on this we have proposed the appropriate overlap and exposure interval for mobile road inventory system.