• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.89-93
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• 2002

The physiology and morphology of cornea has effected on the ocular refractive status. Therefore the measurement of the anterior corneal surface by keratometer is used the treatment of the spectacles and contact lens by optician, optometrist, and ophthalmologist. Furthermore, currently the most corneal topographic mapping system have used the clinical optical shop, eye research center, and eye hospital. Because this method have a very fine data comparative to the previous instrument. The authors have measurement the cornea of the man college students by the corneal topographic mapping method. Especially this data will applied the clinical practice for the contact lens fitting. Especially in Korea, many man college students use the contact lens for the visual acuity and a beauty. Therefore the contact lens wear have increase per every year.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.257-260
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• 2007

The government is spending a large amount of budget to establish NGIS due to the importance of geospatial information. This paper deals with the study of schema mapping technique which can efficiently establish military topographic DB forest layer using digital forest map and other existing geospatial DB. In order to accomplish this 1) each schema of these types of DB was analyzed then, 2) mapping table which connects related attributes was created and finally, 3) military topographical DB forest layer of the area of interest was efficiently established. This research was able to display solutions that resolved compatibility issues between existing geospatial DB of these types, established by the schema mapping techniques described in this research.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.625-633
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• 2007

Recently human beings are enforcing marine investigations to extend their living environment from land to the sea. Therefore, this study grasped objects in the bottom of the sea and its topographical undulation and acquired topographic map with a sound detector. In result, This study acquired their images with a sound detector and can draw up a Drawing of Sea Mapping and a three-dimensional modeling map.

• Korean Journal of Remote Sensing
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• v.24 no.5
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• pp.453-462
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• 2008

The objective of this paper is to compare the prediction performances of different landslide hazard maps based on topographic data stemming from different sources of elevation. The geostatistical framework of kriging, which can properly integrate spatial data with different accuracy, is applied for generating more reliable elevation estimates from both sparse elevation spot heights and exhaustive ASTER-based elevation values. A case study from Boeun, Korea illustrates that the integration of elevation and slope maps derived from different data yielded different prediction performances for landslide hazard mapping. The landslide hazard map constructed by using the elevation and the associated slope maps based on geostatistical integration of spot heights and ASTER-based elevation resulted in the best prediction performance. Landslide hazard mapping using elevation and slope maps derived from the interpolation of only sparse spot heights showed the worst prediction performance.

• Journal of the Korean Institute of Rural Architecture
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• v.23 no.4
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• pp.1-12
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• 2021

Recently, the use of unmanned aerial vehicles (UAVs) is increasing in the field of land information acquisition and terrain exploration through high-altitude aerial photography. High-altitude aerial photography is suitable for large-scale geographic information collection, but has the disadvantage that it is difficult to accurately collect small-scale geographic information. Therefore, this study used low-altitude UAV to monitor changes in small rural spaces around rural resources, and the results are as follows. First, the low-altitude aerial imagery had a very high spatial resolution, so it was effective in reading and analyzing topographic features. Second, an area with a large number of aerial images and a complex topography had a large amount of point clouds to be extracted, and the number of point clouds affects the three-dimensional quality of rural space. Third, 3D mapping technology using point cloud is effective for monitoring rural space and rural resources because it enables observation and comparison of parts that cannot be read from general aerial images. In this study, the possibility of rural space analysis of low-altitude UAV was verified through aerial photography and analysis, and the effect of 3D mapping on rural space monitoring was visually analyzed. If data acquired by low-altitude UAV are used in various forms such as GIS analysis and topographic map production it is expected to be used as basic data for rural planning to maintain and preserve the rural environment.

• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.179-197
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• 2020

Topographic normalization reduces the terrain effects on reflectance by adjusting the brightness values of the image pixels to be equal if the pixels cover the same land-cover. Topographic effects are induced by the imaging conditions and tend to be large in high mountainousregions. Therefore, image analysis on mountainous terrain such as estimation of wildfire damage assessment requires appropriate topographic normalization techniques to yield accurate image processing results. However, most of the previous studies focused on the evaluation of topographic normalization on satellite images with moderate-low spatial resolution. Thus, the alleviation of topographic effects on multi-temporal high-resolution images was not dealt enough. In this study, the evaluation of terrain normalization was performed for each band to select the optimal technical combinations for rapid and accurate wildfire damage assessment using PlanetScope images. PlanetScope has considerable potential in the disaster management field as it satisfies the rapid image acquisition by providing the 3 m resolution daily image with global coverage. For comparison of topographic normalization techniques, seven widely used methods were employed on both pre-fire and post-fire images. The analysis on bi-temporal images suggests the optimal combination of techniques which can be applied on images with different land-cover composition. Then, the vegetation index was calculated from the images after the topographic normalization with the proposed method. The wildfire damage detection results were obtained by thresholding the index and showed improvementsin detection accuracy for both object-based and pixel-based image analysis. In addition, the burn severity map was constructed to verify the effects oftopographic correction on a continuous distribution of brightness values.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.27-34
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• 1993

The construction of the accurate, economic topographic information for a sorts of work and a base facilities of country is one of the very important subjects. In this paper, Global network which include south KOREA and Regional network which include Chung-Nam/Chung-Buk provinces were designed, obtained WGS84 coordinates of control points in networks by GPS. The coefficients of transformation between WGS84 coordinates and Bessel coordinates in consideration of geoid undulations was derived by 7-parameter method. Also, the efficiency of 7-parameter method was proved through successful application of T.M. and U.T.M projection for the precise mapping, and the effectiveness of the aquisition of three dimensional topographic information by GPS was suggested.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.1-12
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• 2017

Planting trees is a very common practice in the coastal dunefields of South Korea as a way to stabilize dune landscapes and protect inland residential areas from strong winds and blown sands. On the other hand, disturbing the original foredune environment may deteriorate the ability of coastal landsto recover from coastal erosion after storms, causing a retreat of coastline. However, there is little information of this sort on the surface of forested dunefields. Airborne LiDAR or drone-based mapping is not easily applicable in such areas. In this study, we developed a digital terrain model of Dasari dunefields, Chungnam Province, based on direct topographic surveys with real-time kinematic GPS and total stations. We also analyzed previous two aerial photographs taken in 1947 and 1966, in order to detect an older landforms of the dunefields. Results suggested that there have been little changes in geomorphology of the Dasari dunefields for the last 50 years, despite continued tree plantings. Today, there are remains of U-shaped structures such as blowouts and parabolic dunes in the dunefields.

• Spatial Information Research
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• v.10 no.4
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• pp.533-550
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• 2002

Soil organic matter (SOM) content and other physical soil properties were extracted from a digital soil database, the Soil Survey Geographic (SSURGO) database, to map the amount of SOM and determine its relationship with topographic positions in floodplain areas along a river basin in Douglas County, Kansas. In the floodplains, results showed that slope and SOM content had a significant negative relationship. Soils near river channels were deep and nearly level, and they had the greatest SOM content in the floodplain areas. For the whole county, SOM content was influenced primarily by soil depth and percent SOM by weight. Among different slope areas, soils on mid-range slopes (10-15%) and ridgetops had the highest SOM content because they had relatively high percent SOM content by weight and very deep soils, respectively. SOM content was also significantly variable among different land cover types. Forest/woodland had significantly higher SOM content than others, followed by cropland, grassland, and urban areas.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1470-1472
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• 2003

Hyperion, as hyperspectral data, is carried on NASA’s EO-1 satellite, can be used in more subtle discrimination on forest cover, with 224 band in 360 ?2580 nm (10nm interval). In this study, Hyperion image is used to investigate the effects of topography on the classification of forest cover, and to assess whether the topographic correction improves the discrimination of species units for practical forest mapping. A publicly available Digital Elevation Model (DEM), at a scale of 1:25,000, is used to model the radiance variation on forest, considering MSR(Mean Spectral Ratio) on antithesis aspects. Hyperion, as hyperspectral data, is corrected on a pixel-by-pixel basis to normalize the scene to a uniform solar illumination and viewing geometry. As a result, the approach on topographic effect normalization in hyperspectral data can effectively reduce the variation in detected radiance due to changes in forest illumination, progress the classification of forest cover.