• 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.

• 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.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.207-218
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• 2014

The information on the land cover along stream corridor is important for stream restoration and maintenance activities. This study aims to review the different classification methods for mapping the status of stream corridors in Seom River using airborne RGB and CIR digital ortho imagery with a ground pixel resolution of 0.2m. The maximum likelihood classification, minimum distance classification, parallelepiped classification, mahalanobis distance classification algorithms were performed with regard to the improvement methods, the skewed data for training classifiers and filtering technique. From these results follows that, in aerial image classification, Maximum likelihood classification gave results the highest classification accuracy and the CIR image showed comparatively high precision.

• 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.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.273-276
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• 2007

In this study, we generated DSM(Digital Surface Model)s and orthophotos with both LIDAR data and scanned aerial photos and compared them with those generated from only the scanned photos. We checked the relief displacements of buildings appearing in the generated orthophotos, where the displacement should not be exist in a true-orthophoto. The RMSE of the relief displacement in the orthophoto generated using a LIDAR DSM is 3 m while the RMSE in the orthophotos from a DSM based on the image matching is 6.1 m. It was revealed that the orthophoto from a LIDAR DSM are closer to a true-orthophoto. But the results in the accuracy test and similarity evaluation of the generated orthophotos were contrary to former results because the roof texture of buildings were expanded to occlusion areas around the buildings. With the central area of the photo, we can generate sufficiently accurate true-orthophotos using a LIDAR DSM.

• Journal of the Korea Safety Management & Science
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• v.9 no.5
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• pp.97-101
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• 2007

As the use of vehicle route application and LBS(location based service) are fast grew, the importance of maintaining road network data is also increased. To maintain road data accuracy, we can collect road data by driving real roads with probe vehicle, or using digital image processing for the extraction of roads from aerial imagery. After compare the new road data to current database, we can update the road database, but that job is mostly time and money consuming or can be inaccurate. In this paper, an updating method of using GPS(global positioning system) enabled cell phone is proposed. By using GPS phone, we can update road database easily and sufficiently accurately.

• ETRI Journal
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• v.40 no.6
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• pp.788-793
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• 2018

3D reconstruction of urban architecture, land, and roads is an important part of building a "digital city." Unmanned aerial vehicles (UAVs) are gradually replacing other platforms, such as satellites and aircraft, in geographical image collection; the reason for this is not only lower cost and higher efficiency, but also higher data accuracy and a larger amount of obtained information. Recent 3D reconstruction algorithms have a high degree of automation, but their computation time is long and the reconstruction models may have many voids. This paper decomposes the object into multiple regional parallel reconstructions using the clustering principle, to reduce the computation time and improve the model quality. It is proposed to detect the planar area under low resolution, and then reduce the number of point clouds in the complex area.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.489-492
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• 2000

본 논문에서는 영상 항법 변수 추출 알고리듬의 실시간 구현에 관해 연구하였다. 영상 항법 변수 추출 알고리듬은 이전 위치를 기준으로 현재 위치를 추정해내는 상대위치 추정 알고리듬과 상대위치 추정에 의해 누적되는 오차를 보정하기 위한 절대위치 보정 알고리듬으로 구성된다. 절대위치 보정 알고리듬은 고해상도 영상과 IRS (Indian Remote Sensing) 위성영상을 기준영상으로 이용하는 방법 및 DEM (Digital Elevation Model) 을 이용하는 방법으로 구성된다. 하이브리드 영상 항법 변수 추출 알고리듬을 실시간으로 구현하기 위해 MVP (Multimedia Video Processor)로 명명된 TMS320C80 DSP (Digital Signal Processor) 칩을 사용하였다. 구현된 시스템은 MVP의 부동 소수점 프로세서인 MP (Master Processor) 를 고정 소수점 프로세서인 PP (Parallel Processor) 를 제어하거나 삼각함수 계산과 같은 부동 소수점 함수를 계산하는데 사용하였고, 대부분의 연산은 PP를 사용하여 수행하였다. 처리시간이 많이 필요한 모듈에 대해서는 고속 알고리듬을 개발하였고, 4개의 PP를 효율적으로 사용하기 위한 영상분할 방법에 대해 제안하였다. 비행체에서 캡코더를 이용해 촬영한 연속 항공 영상과 비행체의 자세정보를 입력으로 실시간 시뮬레이션 하였다. 실험결과는 하이브리드 항법 변수 추출 알고리듬의 실시간 구현이 효과적으로 구현되었음을 나타내고 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.697-702
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• 2015

Recently, the need of effective technologies for disaster damage investigation is increasing. Development of geospatial information technology like UAV is the useful method for quick damage investigation. In this research, to assess the applicability of geospatial information constructed by UAV, we produced ortho images about research area and compared them with digital topographic maps for accuracy evaluation. As a result, ortho images showed within 30cm difference with 1/5,000 digital topographic maps, we could present the possibility to utilize for producing disaster information using UAV because of its effective construction and calculation of disaster information.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.593-598
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• 2006

High-resolution satellite imagery has many benefits, compared to aerial photo in the wide area as well as multi-spectral character. So, it can be used well for constructing GIS data when making digital map. This study analysed the possibilities that road information derived automatically from IKONOS can be used for making ITS system or updating digital map of the urban areas where change frequently and producing satellite image map. In this study, Sobel was applied for road edge dectection after low pass filtering. As the results, it's possible for low pass filtering and high pass filtering to be used as the basic data for ITS construction when extracting edge roads and constructs according to the characteristic of high-resolution satellite imagery.