• Journal of Korean Society for Geospatial Information Science
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• v.2 no.1 s.3
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• pp.93-98
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• 1994

This image of Kangseogu in Pusan, is a digital merge of aerial photos by scale of 1/1,200 map. The merge was carried out 2nd affine and bilinear interpolation. It can improve digital classification to help choose training sites and interprete classification results, and improve visual interpretation, as in this case, by adding detailed information to the multispectral TM data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.1
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• pp.59-66
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• 2000

This study describes the precise DTM by image processing method through scanning the positive film of aerial photo using scanner instead of plotter. First, scanned the positive film of aerial photo by drum scanner and flatbed scanner in different resolution, and then compared the height from image processing method using auto correlation method with height which is taken using $50^m{\times}50^m$ grid in 1 :5,000 geographical map. It shows that heights from aerial photo image of high resolution obtained from scanner are comparable to the heights from 1：5,000 geographical map.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.116-124
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• 2008

This study presents the application of multi-temporal and multi-scale panchromatic aerial photos for change detection in a small urban area. For aerial photos of the scale of 1:20,000 taken in 1987 and 1996 and the scale of 1:37,500 taken in 2000. Pre-processing that make the same conditions to all of the aerial photos was carried out through geometric correction, registration, contrasting, resamplimg, and mosaicking and then change detection were carried out respectively by image differencing and image ratio techniques. As a result, the change of urban features and landcover were able to be detected from panchromatic aerial photos that is single-band images and then the detected change results were compared between both techniques.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.207-220
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• 1997

This study aims to develope the production method of digital image map of high capable utiliy and terrain interpretability using aerial photo and Geospatial Information System. Theory and efficient practical method was studied to generate tile digital image map with low-cost personal computer system using the merging procedure of raster scanned aerial photo and vector topographic map. Determination theory of ground coordinates, digital image processing, production of digital elevation model was reviewed. And some chariteristics of digital image map, image collection method and significant concepts of digital image processing was studied. Also input and output way of image data to generate the digital image nap, production method of orthophoto map using aerial photo through digital differential rectification was studied. As the result, digital image map was produced and analyzed through the above mentioned procedures.

• 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 the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.283-292
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• 1999

Aerotriangulation for the large scale mapping(photo-scale l/5,000) was studied with the projection center determined by kinematic DGPS positioning. For the feasibility study, the accuracy and error was analyzed with the comparison between a projection center from the conventional model adjustment and the projection center determined by the kinematic DGPS positioning. Kinematic DGPS-supported Bundle adjustment was also performed. The accuracy of projection center, determined by L1 phase data observed within 30 km from base station, was stable, and the planimetric accuracy(RMS) is 13 cm and the vertical accuracy(RMS) is 15 cm with 4 ground control points, which satisfies the national standard of digital mapping. Thus, this study shows that GPS-assisted aerotriangulation can be used for economic digital mapping.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.381-388
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• 2008

In the common practice of air-photographing measurement aerial-photogrammetric, the location of camera at the time of photographing is identified by performing aerotriangulation. However, installing ground-base station to enable aerotriangulation takes majority portion of a map making cost. Aerial-photogrammetric has shown a great improvement helped by steady upgrading in equipment and development in quantitative study. Aerotriangulation can be replaced by Direct Georeferencing, which uses GPS/INS to identify a camera location and to produce detailed information. An innovative technique replacing aerotriangulation, it has a disadvantage that base station has to be available in the area of photographing. The study intends to suggest a method applying VRS in GPS/INS aerotriangulation. Despite the fact that Direct Georeferencing is the innovated technique which substitutes existing aerotriangulation, it still need to install the ground-base station in GPS/INS aerotriangulation. GPS/INS data was analyzed with 4 different cases in order to accomplish the purpose of this study. In addition, in the thesis, it was approved that VRS can be utilized to make small-scale map as accurate as base station. This study is expected to improve the efficiency of work by showing that VRS can be used not only in base station but also enabling base station in the ground-access challenging area.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.131-142
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• 1994

Generally, there are two methods which generates the base map of Geo-Spatial Information System(GSIS). one is the digitizing of existing map, and the other is the analytical plotting method editing data acquired by sensors using computers. But the analytical plotting method and method of the digitizing of existing map is technically complex and has the disadvantages in the costs and time. The subject region of study(the Kwangyang province), was photographed by aircraft, and photographing scale was 1/6,000. Then this area was divided into two specific regions, the residential area, and the agricultural area. In this study, we developed the algorithm that generated base map of database in GSIS from the aerial photo. This algorithm is as followed. First, the digital aerial photos were generated using these aerial photos. Second, these digital aerial photos were enhanced by implementing the histogram equalization. Third, the objects of the enhanced images were extracted by implementing thresholding and edged detection techiques of image segmentation. Finally, these images could be used to updated the base map of database in GSIS. The result obtained from this study showed that method used by this study were more efficient than existing method in costs and time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.53-62
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• 2016

In recent years, UAV Photogrammetry based on an ultra-light UAS(Unmanned Aerial System) installed with a low-cost compact navigation device and a camera has attracted great attention through fast and accurate acquirement of geo-spatial data. In particular, UAV Photogrammetry do gradually replace the traditional aerial photogrammetry because it is able to produce DEMs(Digital Elevation Models) and Orthophotos rapidly owing to large amounts of high resolution image collection by a low-cost camera and image processing software combined with computer vision technique. With these advantages, UAV-Photogrammetry has therefore been applying to a large scale mapping and cadastral surveying that require accurate position information. This paper presents experimental results of an accuracy performance test with images of 4cm GSD from a fixed wing UAS to demarcate parcel boundaries in agricultural area. Consequently, the accuracy of boundary point extracted from UAS orthoimage has shown less than 8cm compared with that of terrestrial cadastral surveying. This means that UAV images satisfy the tolerance limit of distance error in cadastral surveying for the scale of 1: 500. And also, the area deviation is negligible small, about 0.2%(3.3m²), against true area of 1,969m² by cadastral surveying. UAV-Photogrammetry is therefore as a promising technology to demarcate parcel boundaries.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.425-435
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• 2014

The research for extracting man-made features such as building and road from the aerial photograph or satellite imagery has been performed actively. As lately the resolution of digital aerial photographs was improved, unwanted features(noise) would be often detected. An edge detection algorithm is developed to make up for such a noise problem, make boundaries of wanted objects clear and extract only needed features. The algorithm developed in this research performs separating RGB channels, differencing between channels, transforming in to binary images, excluding noises and restoring shapes, and edge extraction in order. The images to be used for edge detection are prepared through bundle adjustment, DTM extraction, orthorectification and mosaicking. The roof edges of small building on preprocessed digital aerial orthophotos were extracted using the algorithm developed in this study. The validity of the algorithms was proved by comparing edge results of small building extracted in this study with those of conventional methods.