• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.1
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• pp.61-67
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• 1999

A watershed terrain factor is known to the very important in studies of a stream and a watershed. We have obtained the terrain factor in map directly or we have generated it in a digitalized map. In this study, DTED (Digital Terrain Elevation Data) offering in DMA(Defense Mapping Agency) was used to create a stream and a watershed and to extract the terrain factor. As comparison of the terrain factors gererated in digitalized map with the terrain factors extracted in DTED, DTED could be used to extract a terrain factor for a watershed management.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.88-98
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• 2024

In this paper, an Automatic Terrain Following (ATF) Simulator using Digital Terrain Elevation Data (DTED) was proposed. This ATF Simulator consists of a Flight Simulator, a Radar Simulator, and a Terrain Following Computer (TFC) Simulator. DTED and radar scan data generated with DTED were used as the terrain information necessary for terrain following. The ATF Simulator provides three modes of operation: a passive mode that uses DTED, an active mode that uses radar scan data, and a hybrid mode that uses both. We developed an ATF Simulator that could reduce the cost and time required to develop a terrain following system using the LabVIEW development environment and the MATLAB App Designer development environment. It was verified by confirming that the ATF Simulator met all functional requirements.

• Journal of Industrial Technology
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• v.18
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• pp.35-41
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• 1998

A watershed terrain factor is known to the very important in studies of a stream and a watershed. We have obtained the terrain factor in map directly or we have generated it in a digitalized map. In this study, DTED(Digital Terrain Elevation Data) offering in DMA(Defense Mapping Agency) was used to create a stream and a watershed and to extract the terrain factor. As comparison of the factors gererated in digitalized map the terrain factors extracted in DTED, DTED could be used to extract a terrain factor for a watershed management.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.3
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• pp.19-32
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• 2002

Topographic information is indispensable in the applications that require elevational data. These applications are exemplified by watershed partition, extraction of drainage networks, viewshed analysis, derivation of geomorphologic features, quantification of landslide-terrain, and identification of topographic settings susceptible to landsliding. Therefore, we study the accuracy of data on topographic parameters derived from digital elevation models(DEMs). This research wished to analyze the effect that data source and grid size get in topography parameter using gridded DEM. An analysis of topography parameter extract and compared drainage basin, watershed slope, stream network using DEM is constructed by digital map and DTED DEM. Especially, when extract stream network from gridded DEM, received much effects according to threshold value of flowaccumulation regardless of DEM grid size. Therefore, this study applied equal threshold value of flowaccumulation for two data sources, and compare and analyzed stream network.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.73-78
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• 2009

Real-time 3D visualization of terrain data is one of the important issues in GIS(Geographic Information System) field. We present a real-time terrain rendering engine that can use several types of GIS data source such as DEM(Digital Elevation Map), DTED(Digital Terrain Elevation Data) and LIDAR(Light Detection And Ranging). Our rendering engine is a quadtree-based terrain rendering framework with several acceleration modules. This can generate an ocular and binocular image. Also it can be applied to the flight simulation, walk-through simulation and a variety of GIS applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.99-105
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• 2008

The analysis of LOS(Line-Of-Sight) is defined as an "unobstructed view between two points". The LOS results may be influenced by terrain source, algorithm/interpolation method, etc. In the area denies any access and flight over, LOS results would be doubtful because of low precision of terrain data therefore have limitations of referring to many military applications. Using LIDAR data, LOS Analysis was performed by changing DTED resolution(1$\sim$30m) and LOS distance(50$\sim$2000m). The results of experiment shows that LOS analysis for small area, such as DMZ surveillance, were heavily influenced by DTED resolution.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.103-109
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• 2007

Ortho images and Digital Elevation Model (DEM) have been applied in various fields. It is necessary to acquire Ground Control Points (GCPs) for processing high resolution satellite images. However surveying GCPs require many time and expense. This study was performed to investigate whether GCPs automatically extracted from ortho images and DTED Level 2 can be applied to sensor modeling for high resolution satellite images. We analyzed the performance of the sensor model established by GCPs extracted automatically. We acquired GCPs by matching satellite image against ortho images. We included the height acquired from DTED Level 2 data in these GCPs. The spatial resolution of the DTED Level 2 data is about 30m. Absolution accuracy of this data is below 18m above MSL. The spatial resolution of ortho image is 1m. We established sensor model from IKONOS images using GCPs extracted automatically and generated DEMs from the images. The accuracy of sensor modeling is about $4{\sim}5$ pixel. We also established sensor models using GCPs acquired based on GPS surveying and generated DEMs. Two DEMs were similar. The RMSE of height from the DEM by automatic GCPs and DTED Level 2 is about 9 m. So we think that GCPs by DTED Level 2 and ortho image can use for IKONOS sensor modeling.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.13-19
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• 2005

선박조종시뮬레이터는 교육훈련생들에게 실제와 비슷한 환경을 제공하여 교육훈련의 효과를 높일 수 있는 장점을 가지고 있다. 그러므로 선박조종시뮬레이터에는 선박의 정확한 수학적 모델과 실제와 거의 동일한 3차원 화면이 필요하다. 이 연구에서는 전자해도와 고도데이터를 이용한 3차원 영상 제작법에 대해 고찰하고자 한다. 전자해도는 전 세계적으로 표준화 되어 있어 정확성이 가장 뛰어날 뿐만 아니라 수심, 항해물표 등 각종 데이터를 가지고 있어 보다 많은 정보를 선박조종시뮬레이터에 적용할 수 있는 장점을 가지고 있다. 그리고 고도데이터의 경우 그 정확성으로 기존의 해상환경 데이터베이스보다 훨씬 현실감을 준다. 전자해도 및 고도데이터를 이용하여 해상환경을 제작 시 정확한 많은 정보의 제공이 가능하며, 기존의 방법에 비해 제작시간을 상당히 감소시킬 수 있을 것으로 판단된다.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.58-65
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• 1996

The environment in urban are becoming worse and forest is being recognized the major part of city by the increase of population and facilities. This study was carried out to analyze topographic environment as the basis for reasonable management and utility of forest situated in Taejon city and its vicinities using Sandst-5 TM and digital terrain elevation data(DTED). Forest area was extracted by Landsat-5 TM data. Distribution of elevation, slope and aspect was derived from digital terrain elevation data. The research area to analyze ropographic environment for urban forest were Bomumsan, Bongsan, Kabhasan, Sikchangsan, and Kyechoksan. Forest, the largest area in Taejon covers 55.1% of totaf area. This is more 5 times than urban area. 70.8% of forest area in Taejon city is located in elevation of lower than 200m and 4.8% of that is located in elevation of upper than 400m. Distribution of elevation is 45.7% of total area for 100m to 200m in Kyechoksan and is 92.4% of total area for lower than 300m in Bomumsan. Elevation of upper than 300m is 20.4% of total area in Kabhasan and is 46.6% of total area in Sikchangsan. The slope of more 20 digree is over 50% of total area in every area except for Bonsan and 35.2% of total area in Sikchangsan and Kahasan than in Bomumsan and Kyechoksan.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.9
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• pp.888-897
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• 2015

A flight capability to take a terrain following flight near the ground is required to reduce the probability that a fighter aircraft can be detected by foe's radar fence in the battlefield. The success rate for mission flight has increased by adopting TFS (Terrain Following System) to enable the modern advanced fighter to fly safely near the ground at the low altitude. This system has applied to the state-of-the-art fighter and bomber, such as B-1, F-111, F-16 E/F and F-15, since the research begins from 1960's. In this paper, the terrain following system and GCAS (Ground Collision Avoidance System) was developed, based on a digital database with UTAS's TERPRROM (TERrain PROfile Matching) equipment. This system calculates the relative location of the aircraft in the terrain database by using the aircraft status information provided by the radar altimeter and the INS (Inertial Navigation System), based on the digital terrain database loaded previously in the DTC (Data Transfer Cartridge), and figures out terrain features around. And, the system is a manual terrain following system which makes a steering command cue refer to flight path marker, on the HUD (Head Up Display), for vertical acceleration essential for terrain following flight and enables a pilot to follow it. The cue is based on the recognized terrain features and TCH (Target Clearance Height) set by a pilot in advance. The developed terrain following system was verified in the real-time pilot evaluation in FA-50 HQS (Handling Quality Simulator) environment.