• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.85-92
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• 2003

Application of traditional aerial survey technologies for topographic mapping purposes has a number of principal problems. The growing worldwide acceptance of digital orthophotos has understood this need. Many trekking and expedition teams are expecting digital orthophoto and consequently 3D animation of the highest peaks and possible trekking routes, camping sites and information on how difficult the routes may be. In recent years, inexpensive computers and advance of computer technologies contributed to the rapid development of digital photogrammetry (Dowman et al., 1992; Heipke, 1995). Successful implementation of digital photogrammetric workstations in mapping have been found in various disciplines (Chen et al., 1998; Skalet et al., 1992). This paper highlights the results of the conventional photogrammetry and the possible advantages of digital photogrammetry over these and also the problems, issues and implications during digital Photogrammetric processing of high mountainous region in Asia.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2593-2600
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• 2013

The main purpose of this study is to carry out the performance evaluation of Ultra-light Fixed Wing UAV(Unmanned Aerial Vehicle) photogrammetry which is being, currently, applied for various fields such as cultural assets, accident survey, military reconnaissance work, and disaster management at home and abroad. Firstly, RMSE estimation of Aerial Triangulation (AT) are within approximately 0.10 cm in position (X, Y). And through the comparison of parcel's boundary points coordinates by terrestrial surveying and by UAV photogrammetry, the analysis shows that RMSE are shifted approximately 0.174~0.205 m in X-direction, 0.294~0.298 m in Y-direction respectively. Lastly, parcel's area by orthophoto of UAV photogrammetry and by that of cadastre register has been shown the difference by 0.118 m2. The results presented in this study is just one case study of orthophoto accuracy assessment of Ultra-light fixed wing UAV photogrammetry, hereafter various researches such as AT, direct-georeferencing, flight planning, practical applications, etc. should be necessary continuously.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.97-104
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• 2016

In this study, analyze and monitor the change of the ecological restoration area inside the open-pit mine in Gangwon-do. and to analyze and monitor the change of ecological restoration area. analyzed the distribution of vegetation using high-resolution orthophoto of various periods and analyzed terrain change using DSM/DEM in study area. Therefore, orthophoto and 포인트 클라우드 were collected from 2014 aerial laser surveying and 2015 fixed-wing drone photogrammetry. In addition, orhtophoto and 포인트 클라우드 were produced by using rotary-wing drone photogrammety in 2016, and change of ecological restoration area was analyzed using this. As a result, it's possible to perform change monitoring of the open-pit mine ecological restoration area. using nEGI and VARI, about 10-30% of the area ratio of the result of extracting vegetation distribution area is distributed, and the comparison DSM and DEM cross section and restoration plan line, the cross section made by using the drone were similar, and the earth-volume analysis was possible.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.19-27
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• 2014

Kompsat-3 is an optical high-resolution earth observation satellite launched in May 2012. In addition to its 0.7m spatial resolution, Kompsat-3 is capable of in-track stereo acquisition enabling quality Digital Elevation Model(DEM) generation. Typical DEM generation procedure requires accurate control points well-distributed over the entire image region. But we often face difficult situations especially when the area of interests is oversea or inaccessible area. One solution to this is to use existing geospatial data even though they only cover a part of the image. This paper aimed to assess accuracy of DEM from Kompsat-3 with different scenarios including no control point, Rational Polynomial Coefficients(RPC) relative adjustment, and RPC adjustment with control points. Experiments were carried out for Kompsat-3 stereo data in USA. We used Digital Orthophoto Quadrangle(DOQ) and Shuttle Radar Topography Mission(SRTM) as control points sources. The generated DEMs are compared to a LiDAR DEM for accuracy assessment. The test results showed that the relative RPC adjustment significantly improved DEM accuracy without any control point. And comparable DEM could be derived from single control point from DOQ and SRTM, showing 7 meters of mean elevation error.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.49-58
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• 2016

Applications of drone in various fields have been increasing in recent years. Drone has great potential for forest management. Therefore this paper is using drone for forest damage areas. Forest damage areas is divided into caused by anthropogenic and occurs naturally, the possibility of disasters, such as slope sliding, slope failures and landslides, sediment runoff exists. Therefore, this research was to utilize the drone photogrammetry to perform the damage analysis of forest damage areas. Geometrical treatment processing results in Drone Photogrammetry, the plane position error RMSE was ${\pm}0.034m$, the elevation error RMSE was ${\pm}0.017m$. The plane position error of orthophoto RMSE was ${\pm}0.083m$, the elevation error of digital elevation model RMSE was ${\pm}0.085m$. In addition, It was possible to current state analysis of damage in forest damage areas of airborne LiDAR data of before forest damage and drone photogrammetry data of after forest damage. and application of drone photogrammetry for production base data for restoration and design in forest damage areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.2
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• pp.57-68
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• 2004

Recently in order to more effectively and scientifically process forest official tasks, which have been focused on documents and inventories, they should be applied with the up-to-date spatial information technologies. Especially, the forest resource information management based on GIS(geographic information system) and aerial orthophoto is expected not only to play an important role as DSS(decision support system) for domestic forest conservation policy and forestry development industry but also to service forest resource information toward people such as the owners of a mountain rapidly. In this study, the important forest information such as digital topography map, digital forest type map, digital forest cadastral map, digital aerial photographs and attribute data were first reprocessed and constructed in DBMS(data base management system). In addition, forest officials could analyze and retrieve forest information by using detail sub-application systems such as forest cadastral retrieval, forest land development information management, reserved forest information management and forest resource information retrieval. For this, the user interface is developed by using Visual Basic 6.0 and MapObjects 2.1 of ESRI based on CBD(component based development) technology. The result of developing this system will not only perform constructing economical forest and better environment but also be the foundation of domestic spatial technology for forest resource management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.245-251
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• 2004

Recently, in a field of cadastre, a computerization of cadastral map is in progress with great growth of GSIS field. Also, the needs fer the integration of land and building information are widely increasing for integral-management and its application of various land related information. Through a revision of cadastral laws to replace the existing 2D-Cadastre with the 3D-Cadastre, a legal basis to register the position of buildings and facilities is prepared in the governmental or civil fields. This paper presented 3D-Cadastre theory that has been studied on Europe and surveyed building position directly with Totalstation at cadastral control point after choosing pilot test area, Also, the most efficient surveying method of registering building in a cadastral map is presented with comparing and analyzing building position after surveying digital orthophoto and digital map. And it is constructed a 3D information cadastral map model that can make the integral management of land, building, connecting land recorders, building management ledgers, building titles, building pictures, and related attribute information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.253-259
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• 2004

The sheetwise cadastral map data needs to become a Serial Cadastral Map (SCM) database for the promotion of the reliability of cadastral surveying, for the efficient operation of the Parcel Based Land Information System, and for the convenient use of land information as well. A large amount of money and time are required for the editing process of producing SCM DB in accordance with the $\ulcorner$Guideline for the Production of Serial Cadastral Maps$\lrcorner$ by the Ministry of Construction & Transportation if any of field surveying techniques is accompanied by. In addition, a boundary line that extends to a neat line does not meet the counterpart of the neighboring map sheet at a point. Such cases frequently occur and are much dependent upon the decisions of individuals in charge of editing or inspecting. The core processes of the research, firstly overlay SCM produced by the edition of the sheetwise cadastral maps with Autodesk Map on orthophoto images, secondly adjust the parcel boundaries which are delineated over more than one map sheet, and lastly compare the original boundary coordinates and areas with the corresponding adjusted ones and calculate root mean square errors (RMSEs). The research aims at promoting the quality of SCM by minimizing the inconsistency of parcel boundaries by means of the comparative analysis of the calculated RMSEs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.481-487
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• 2018

This paper proposes a method to detect and monitor the land creeping area using a UAV to analyze the damaged area efficiently. Using a UAV, it was possible to secure the safety of the investigators before the field survey and effectively utilize it to establish an investigation plan because an orthophoto can be used to detect and scale the cracks in a land creeping area. In addition, it was possible to analyze the scale of the crack quantitatively by extracting the topographic information from the orthophoto. The study sites were found to have a total crack area of 1.01 ha, a length of 1.07 km, an average width of 10 m, and a step distance of 1 to 10 m. Periodic UAV measurements can be used to detect displacements on the land creeping area and monitor the direction and scale of crack spread. Therefore, it is expected to be used effectively during recovery planning. Applying the UAV to the land creeping area resulted in the qualitative and quantitative results quickly and easily in dangerous mountainous watersheds. Therefore, it is expected that it will contribute to the development of related industries because of the high availability of a UAV in forest soil sediment disasters, such as landslides, debris flow, and land creeping area.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1049-1057
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• 2020

This study aimed to develop a flow measurement method using drone in flood season. Measuring flow in all branches is difficult to conduct annually due to budget and labor limitation, safety and river works. Especially when heavy rain like storm comes, changes in stage-discharge relationship should be reviewed; however, it is usually impeded by the aforementioned issues. To solve the problem, it developed a simple measuring method with a minimum of labor and time. A numeric map and numeric orthophoto coordinate of South Korea are mostly based on Transverse Mercator Projection (TM) in accordance with rectangular coordinate system and use World Geodetic Reference System 1980 (GRS80) oval figure for conversion. Applying a concept of aerial photogrammetry, it located four visible Ground Control Points (GCP) near the river at Uijeongbu-si (Singok Bridge) and Yeongdong-gun (Youngdong 2nd Bridge) station and measured the coordinates using VRS DGPS. Hovering at a same level, drones took orthophoto of water surface at an interval of 3 seconds. It defined the pictures with GRS80 TM coordinate system, a rectangular coordinate system and then conducted an orthometric correction using GCP coordinates. According to X and Y coordinate analysis, it estimated the distance between the floating positions at 3 seconds-intervals and calculated the flow through the flow area according to the flow path. This study attested applicability of the flow measurement method using drone in flood season by applying the rectangular coordinate system based on the concept of aerial photogrammetry.