• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.609-611
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• 2003

In the past, it has always been time -consuming and labor intensive to extract and update Digital Elevation Model (DEM). How to extract highly accurate DEM with efficiently and the most economical method has always been a cutting-edge topic in the remote sensing filed. This paper discusses using PCI Geomatica OrthoEngine software to extract DEM automatically from ASTER stereo satellite images (15 m resolution). For the study, DEMs were extracted for two sites in Taiwan, and the resulting DEMs were found to have RMS errors between 10 and 16 meters in both flat and mountainous areas.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.57-59
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• 2003

Digital surface model generation from IKONOS stereo imagery is a new challenge in photogrammetric community, especially when the satellite company does not provide the raw data as well as their ancillary ephemeris data. In this paper we utilized an estimated relief displacement azimuth and the nominal collection elevation data included in the metadata file to correct the relief displacement of GCPs, together with a linear transformation for geometric modeling of IKONOS imagery. Space intersection is performed by the trigonometric intersection assuming a parallel projection of IKONOS imagery due to its small FOV and frame size. In the experiment, less than 2-meters of RMSE in orbit modeling is achieved denoting the potential positioning accuracy of the IKONOS stereo imagery.

• 대한원격탐사학회지
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• 제25권3호
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• pp.205-214
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• 2009

This paper investigates stereo 3D viewing for linear pushbroom satellite images using the Orbit-Attitude Model proposed by Kim (2006) and using OpenGL graphic library in Digital Photogrammetry Workstation. 3D viewing is tested with KOMPSAT-2 satellite stereo images, a large number of GCPs (Ground control points) collected by GPS surveying and orbit-attitude sensor model as a rigorous sensor model. Comparison is carried out by two accuracy measurements: the accuracy of orbit-attitude modeling with bundle adjustment and accuracy analysis of errors in x and y parallaxes. This research result will help to understand the nature of 3D objects for high resolution satellite images, and we will be able to measure accurate 3D object space coordinates in virtual or real 3D environment.

• 대한원격탐사학회지
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• 제17권2호
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• pp.121-129
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• 2001

A DEM(digital elevation model) is generated from a SPOT panchromatic stereo-pair using automated algorithms over a 8 km$\times$10 km region around Mokpo city. The aims are to continue the accuracy assessment over diverse conditions and to examine the applicability of a SPOT DEM for coastal disaster monitoring. The accuracy is assessed with respect to three reference data sets: 10 global positioning system records, 19 leveling data, and 1:50,000 topography map. The planimetric error is 10.6m r.m.s. and the elevation erroer ranges from 12.4m to 14.4m r.m.s.. The DEM accuracy of the flat Mokpo region is consistent with that over a mountainous area, which supports the robustness of the algorithms. It was found that coordinate transformation errors are significant at a few meters when using the data from leveling and topographic maps. The error budget is greater than the requirements for coastal disaster monitoring. Exploiting that a sub-scene is used, the affine transformation improves the accuracy by 50% during the camera modeling.

• 대한원격탐사학회지
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• 제14권2호
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• pp.129-136
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• 1998

지형도를 입력하여 추출된 등고선으로부터 수치고도모델을 생성하는 과정에서 발생하는 문제를 다루고 있다. 흔히 사용되는 선형보간법의 문제점을 지적하고 닫혀진 단일 등고선 내부의 고도 보간방법을 제시한다 .단일 평면상에 제어점이 있어야한다는 제약점을 없애고 공간 상에서 제어점을 찾아낸후 3차곡선으로 보간하는 방법을 기술하고 있다. 인위적인 등고선과 실제의 등고선에 대해서 적용한 결과 자연스럽고 정확한 복원이 이루어졌다.

• 대한원격탐사학회지
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• 제7권2호
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• pp.149-163
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• 1991

This paper discusses the capabilities of airborne remotely sensed data to detect and classify forest damades. In this work the AMS (Aircraft Multiband Scanner) was used to obtain digital imagery at 300m altitude for forest damage inventory in the Black Forest of Germany. MSS(Multispectral Scanner) digital numbers were converted to spectral emittance and radiance values in 8 spectral bands from the visible to the thermal infrared and submitted to a maximum-likelihood classification for : (1) tree species ; and. (2) damage classes. As expected, the resulted, the results of MSS data with high spatial resolution 0.75m$\times$0.75m enabled the detection and identification of single trees with different damages and were nearly equivalent to the truth information of ground checked data.

• 대한원격탐사학회지
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• 제16권4호
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• pp.347-353
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• 2000

The purpose of this paper is to extract DEM (Digital Elevation Model) using KOMPSAT images. DEM extraction consists of three parts. First part is the modeling of satellite position and attitude, second part is the matching of two images to find corresponding points of them and third part is to calculate the elevation of each point by using the result of the first and second part. The position and attitude modeling of satellite is processed by using GCPs. Area based matching method is used to find the corresponding points between the stereo satellite images. The elevation of each point is calculated using the exterior orientation information obtained from sensor modeling and the disparity from the stereo matching. In experiment, the KOMPSAT images, 2592$\times$2796 panchromatic images are used to extract DEM. The experiment result show the DEM using KOMPSAT images.

• 대한원격탐사학회지
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• 제16권2호
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• pp.177-188
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• 2000

Quantitative accuracy assessment of a SPOT DEM (Digital Elevation Model) generated by a fully automatic software is performed along the 90km long coast around Donghae city. The theoretical requirement on the layout of the CPS (Global Positioning System) check points is derived: the Nyquist sampling. Since in practice the Nyquist frequency of a terrain is difficult to determine, the relaxed requirements are introduced and 31 check points are collected accordingly. Accuracy of the SPOT DEM is calculated to be 8.9, 11.5 and 12.0m r.m.s. in latitudinal, longitudinal and elevation directions. The bias is distinguishable from zero only for elevation and is 2.2m. The simple comparison with the world's leading commercial softwares reveals the similar accuracy level.

• 대한원격탐사학회지
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• 제1권1호
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• pp.39-51
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• 1985

The study was emphasized on application of the digital image processing techniques for lineament analysis. The major lineament of the study area belongs to Choogaryong faults which many geologists have studied since 1903. Also the lineament is so significant in geological views, because the lineament runs through Seoul area. The several image processing methods such as gradient, Laplacian and spatial filter have been applied, and the spatial filtering is most suitable method for lineament analysis among them. The lineaments distribute predominently in the N20.deg.-30.deg.E trend and N80.deg.-90.deg.W trend which have the conjugated relationship each other, and it coincides with the Gyeongsang conjugate system. The circular structure of study area was developed by cooling circular joint.

• 디지털산업정보학회논문지
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• 제17권4호
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• pp.95-102
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• 2021

As social interest in the metaverse increases, various metaverse platforms and services are appearing, and various security issues are emerging accordingly. In particular, since all activities are performed in a variety of virtual spaces, and the metaverse utilizes sensing data using various hardware devices, more information is accumulated than other Internet services, and more damage can occur if information security is not guaranteed. Therefore, in this paper, we propose a metaverse security model that considers the major issues mentioned in previous papers and the necessary evaluation factors for the security functions required in the metaverse platform. As a result of performing the performance evaluation of the proposed model and the existing attribute information collection model, the proposed model can provide security functions such as anonymity and source authentication, which were not provided by the existing models.