• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.251-252
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• 2010

Lately, airborne digital camera and airborne laser scanner in field of airborne surveying is used to build geography information such as DEM generation and terrain analysis. In this study, 3D position accuracy is compared medium format CCD camera RCD105 with high resolution airborne digital camera DMC. For this, test area was decided for aerial photograph and ground control points was selected in 1/1,000 scale digital map. In Result, Root Mean Square Error(RMSE) was analyzed between RCD105 and DMC after aerial triangulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.2
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• pp.63-70
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• 2019

Electric transmission towers are facilities to transport electrical power from a plant to an electrical substation. The towers are connected using wires considering the wire tension and the clearance from the ground or nearby objects. The wires are installed on a rights-of-way that is a strip of land used by electrical utilities to maintain the transmission line facilities. Trees and plants around transmission lines must be managed to keep the operation of these lines safe and reliable. This study proposed the use of a low-cost drone photogrammetry for the transmission line rights-of-way mapping. Aerial photogrammetry is carried out to generate a dense point cloud around the transmission lines from which a DSM (Digital Surface Model) and DTM (Digital Terrain Model) are created. The lines and nearby objects are separated using nDSM (normalized Digital Surface Model) and the noises are suppressed in the multiple image space for the geospatial analysis. The experimental result with drone images over two spans of transmission lines on a mountain area showed that the proposed method successfully generate the rights-of-way map with hazard nearby objects.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.137-144
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• 2009

This study aims to develop a 3D map which allows users to better understand the overall topography and to memorize the general concepts of the current location for tourists. The Map also utilizes different forms and color codes of the block units in the panoramic view. First, in preparation for making the road block unit, 28 types of roads presented in common map were defined. Based on the definitions, 12 dominant groups were formed. In designing each form, visual correlation was considered. Second, 42 types of terrain features presented in normal maps were defined for making the panoramic block unit. Then, 2 dominant groups, each contains 5 subgroups, were made according to the assemble pattern and the size of area. On the basis of the grouped units, the panoramic block units were produced with 3D pole line graphics maintaining integration. Lastly, each panoramic block units were categorized by color classes such as blue, green, gray and brown class. The overall color combination of the work was evaluated as well harmonized since the Moon&Spencer's Aesthetic measure value exceeds 0.5.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.283-294
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• 2021

Solar radiation is an important meteorological factor in the agricultural sector. The ground exposed to sunlight is highly influenced by the surrounding terrains especially in South Korea where the topology is complex. The solar radiation on an inclined surface is estimated using a solar irradiance correction factor for the slope of the terrain along with the solar radiation on a horizontal surface. However, such an estimation method assumes that there is no barrier in surroundings, which blocks sunlight from the sky. This would result in errors in estimation of solar radiation because the effect of shading caused by the surrounding terrain has not been taken into account sufficiently. In this study, the shading effect was simulated to obtain the brightness value (BV), which was used as a correction factor. The shaded relief images, which were generated using a 30m-resolution digital elevation model (DEM), were used to derive the BVs. These images were also prepared using the position of the sun and the relief of the terrain as inputs. The gridded data where the variation of direct solar radiation was quantified as brightness were obtained. The value of cells in the gridded data ranged from 0 (the darkest value) to 255 (the brightest value). The BV analysis was performed using meteorological observation data at 22 stations installed in study area. The observed insolation was compared with the BV of each point under clear and cloudless condition. It was found that brightness values were significantly correlated with the solar radiation, which confirmed that shading due to terrain could explain the variation in direct solar radiation. Further studies are needed to accurately estimate detailed solar radiation using shaded relief images and brightness values.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.443-446
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• 2007

The major purpose of the present study is to gauge the general applicability of cadastral surveying and LiDAR surveying. LiDAR survey is the method which obtains Geospatial information of the terrain. We will get a most topographic models at Digital Elevation Model(DEM) using LiDAR survey data. Also, we will consider both the surface parcel partition and volume parcel as a part of Geospatial relationship model. This study will focus on enhancing the efficiency and analysis of continual cadastral map and LiDAR DEM. I would like to close by proposing that LiDAR surveying will contribute in cadastral surveying.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.133-138
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• 2006

Currently high resolution satellite imagery has been used in lots of fields of terrain analysis, ocean development, change detection, cartography, classification, environmental monitoring, earth resource observation, meteorological observation as well as military The accuracy of the 3-D modeling of SPOT-5 stereopair images using these ground control points is about 5m in planimetric distance error and about 2m in height error. This study demonstrates the available ground control points for North Korea, of which accuracy is as good as to generate the digital map at the scale of 1:25,000.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.457-462
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• 2006

Coastline has been considered as fundamental geographic information of a nation. Recently, the coastlines of higher resolution and accuracy with less update period ever than before are increasingly required. This requirement cannot be easily satisfied with the most traditional methods based on field survey such as leveling or GPS measurements. The newly developed airborne LIDAR system can be used as a promising alternative since it rapidly acquire numerous three-dimensional points densely sampled from the terrain around the coastline. Hence, in this study we developed a nearly automatic method to extract the coastline from LIDAR data and applied it to real data to verify its performance. From the comparison of the extracted coastlines with those from a digital map, we conclude that the proposed method can provide more accurate and precise lines.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.105-110
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• 2002

For the accuracy assessment of DTM obtained by Airborne Laser Mapping Systems (ALMS), we selected 500 m spaced test points and analyze the accuracy of the DTM by various methods including GPS survey. To estimate the height at the point in between the test points of the DTM we produced a TIN, and to analyze the accuracy we use a GPS coverage map overlaid with the TIN. Compared with the existing method, DTM by ALMS is shown to be relatively accurate, and therefore, ALMS is applicable to 1/5000 digital terrain mapping.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.71-78
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• 2007

We suggest a multi-path propagation analysis method using DTM(Digital Terrain Map). Generally, the total signal strength at a target is calculated by adding the field propagated in free space and the field reflected from the ground surface. In this paper, we also consider the vertical reflections associated with the vertical surfaces such as precipitous cliffs and electricity pylons in the mountain area. In addition, we primarily take account the main slope of the ground surface to improve the accuracy of the total field density at the target.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.341-344
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• 2010

본 논문은 디코이(Decoy) 안테나를 사용하여 레이다를 보호하기 위한 레이다 전파회피 기술에 대한 것이다. 2개 이상의 디코이를 사용하여 ARM을 방어하는 기술을 디코이의 배치 방법과 배치 거리에 따른 ARM의 요격효과를 시뮬레이션 하고, ARM 방어를 위한 효과적인 디코이 배치 방법 및 배치거리를 제안한다. 또한 실제 DTM(Digital Terrain Map)의 고도 좌표를 적용한 경우 ARM의 타격 오차 등을 시뮬레이션하였다.