• Title/Summary/Keyword: geospatial information

Search Result 1,550, Processing Time 0.029 seconds

The Study on the Mapping of Wind Resource using Moving Filter Technique at Udo, Jeju Island (무빙필터 기법을 적용한 제주 우도지역의 풍력자원지도 작성에 대한 연구)

  • Moon, Seo Jeong;Ko, Jung Woo;Lee, Byung Gul
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.20 no.4
    • /
    • pp.29-36
    • /
    • 2012
  • In order to create a wind resource map, we need wind data, contour map and roughness map. Moving Filter technique was applied to Udo of Jeju Island to improve the accuracy and efficiency of creating roughness map based on the Land Cover Map of the Ministry of Environment. The Land Cover Map was simplified using moving filtering, and the roughness map was created with this Land Cover Map. The wind resource map was created using this roughness map. Finally, we verified the validity and application of moving filter technique for wind resource map. As a result, the wind map which was created using the roughness map with moving filtering showed bias values which were all negative. It means the wind map is underestimated to values of wind energy and RMSE values were also from 0.0237m/s to 0.0253m/s at 50m height. In other words, estimation of wind resource using image filtering provides reliable results at 80m height typically when the wind turbine is installed. Finally, we found that image filtering technique is very useful tool to make wind resource map.

Review and Comparative Analysis of Forest Biomass Estimation Using Remotely Sensed Data: from Five Different Perspectives (원격탐사자료를 이용한 국외 산림 바이오매스 추정 현황 및 비교분석: 다섯 가지 관점에서의 고찰)

  • Cho, Kyung-Hun;Heo, Joon;Jung, Jae-Hoon;Kim, Chang-Jae;Kim, Kyung-Min
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.19 no.1
    • /
    • pp.87-96
    • /
    • 2011
  • Carbon emissions and storages that are strongly related to global warming has have emerged as one of the important issues while many governments and researchers have been interested in climate change and pollution. In this regards, forest biomass estimation is quite importance since forest biomass works as an important medium of the global carbon cycle between the atmosphere and soil. Forest biomass estimation through field survey needs lots of time and labors, and has accessibility issues. Hence, many researchers have focused on the forest biomass approaches based on remotely sensed data. This research comprehensively reviewed forty one international studies using remote sensing data according to five different categories (i.e., location of study area, size of study area, biome, used remote sensing data, and estimation technology). It would be expected that the results of this study can be used for suggesting domestic research directions; domestic research in this field is at the beginning stage in terms of level of technologies and useful materials. As results, 39% out of the reviewed studies used the areas located in North America. 59% out of the researches dealt with small size of the study areas (less than 3,600km2). In case of biome, around 30% of the studies focused on the boreal/taiga areas. Moreover, 35% and 16% of the studies were carried out using Landsat series and Lidar data, respectively. Finally, regression analysis method was most frequently used for forest biomass estimation by 71% out of 41 studies.

Research on the Variation of Deposition & Accumulation on the Shorelines using Ortho Areial Photos (수치항공사진을 이용한 해안선 침퇴적변화에 관한 연구)

  • Choi, Chul-Uong;Lee, Chang-Hun;Oh, Che-Young;Son, Jung-Woo
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.17 no.3
    • /
    • pp.23-31
    • /
    • 2009
  • The border of the shorelines in a nation is an important factor in determining the border of a national territory, but Korea's shorelines are rapidly changing due to the recent rise in sea level from global warming and growth-centered economic policy over the decades of years. This research was done centering on the areas having well-preserved shorelines as they naturally are and other areas having damaged shorelines in their vicinities due to artificial structures at the two beaches located at the neighboring areas and having mutually homogeneous ocean conditions with each other. First, this research derived the shorelines using the aerial photographies taken from 1947 until 2007 and revised the tidal levels sounding data obtained from a hydrographical survey automation system consisting of Echosounder[Echotrac 3100] and Differential Global Positioning System[Beacon]by using topographical data and ships on land obtained by applying post-processing Kinematic GPS measuring method. In addition, this research evaluated the changes and dimensional variations for the last 60 years by dividing these determined shorelines into 5 sections. As a result, the Haewundae Beach showed a total of 29% decrease rate in dimension as of the year 2007 in comparison with the year 1947 due to a rapid dimensional decline centering on its west areas, while the dimension of the Gwanganri Beach showed an increase in its dimension amounting to a total of 69% due to the decrease in flow velocity by artificial structures built on both ends of the beach-forming accumulation; thus, it was found that there existed a big difference in deposition & accumulation tendency depending on neighboring environment in spite of the homogeneous ocean conditions.

  • PDF

Analysis of Non-Barrier Space to Promote the Uses of Convenience Facilities at Passenger Facilities by the Visually Handicapped (시각장애인의 여객시설 내부편의시설 이용증진을 위한 무장애 공간 분석(광명역을 중심으로))

  • Kim, Dong-Moon;Kim, Hwang-Bae;Park, Jae-Kook
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.16 no.2
    • /
    • pp.31-40
    • /
    • 2008
  • The indicators of an advanced society include the overall level of life quality and satisfaction among all the members. The overall life quality has close relationships with accessibility to urban space for the social weak. Access to facilities of interest and right of mobility in urban space are very important issues to the weak class in terms of transportation including the visually handicapped. In particular, great significance is endowed upon transfer facilities, which play mediating roles between facilities like passenger facilities, and the convenience facilities inside for the disabled, which are usually the only means for the disabled to access each facility. As they are provided to the visually handicapped as well, it's very important to analyze the concerned spatial distribution and offer the results. The previous studies on the subject, however, merely covered the perceptions of the users and the related statistical analysis. This study set out to analyze non-barrier space to promote the utilization of convenience facilities at passenger facilities by the visually handicapped and to secure their right of mobility by using a GIS for spatial analysis based on spatial data. The results show that it's urgent to supplement the existing space for the handicapped and that it's necessary to expand convenience facilities for the disabled such as paths with Braille points on them to promote their use of diverse convenience facilities inside.

  • PDF

A Study for Implementing of National GIS Training Program : Analysis of the Results for the First Year (국가 GIS 전문인력양성 활성화 연구 : 1차년도 결과를 중심으로 고찰)

  • Lee, Ho-Geun;Lee, Ki-Won;Lee, Jong-Hun;Yang, Young-Kyu
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.5 no.1 s.9
    • /
    • pp.147-157
    • /
    • 1997
  • A national program for GIS Training had been established by a feasibility study which was performed during the period of from July, 1995 through April, 1996 initiated by Ministry of Science and Technology (MOST). Systems Engineering Research Institute (SERI), one of government-supported institutes in the fields of software development, have taken in charge of Korean GIS training program with emphases on short courses since July, 1996. To distinguish these national programs from those of major commercial GIS software vendor, GIS training programs by executing staffs within SERE have been established with the basis of its own educational paradigm; therefore, they was composed of several specific training curricular developed by executing staffs. In this paper, the practical aspects during execution and progress of these programs are described, and all courses named after decision maker course, GIS manager course, and user course in the first year of GIS training program are evaluated with questionnaire result riven to the trainees. As results, the satisfaction-rate after the decision maker, the GIS manager, and the user course is 84.8%, 81.2%, and 66.7% respectively These whole results are shown as more affirmative ones than expected, and each result, as a kind of feedback of this executing program, plays an important role to flourish Korean GIS training project in future.

  • PDF

Temporal Urban Growth Monitoring using Landsat Imagery and Pycnophypactic Interpolation Method - The case of Seoul Metropolitan Area - (Landsat 영상과 Pycnophylactic 보간 알고리즘에 의한 도시성장 분석 - 서울-경기 도시지역을 중심으로 -)

  • Chang, Hoon
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.11 no.2 s.25
    • /
    • pp.17-28
    • /
    • 2003
  • Since 1970s, Seoul Metropolitan Area has been growing in physical and demographic aspect. A number of new urban fringes, New City, had been particularly developed from the early of 1990s. To examine the urban growth, the population density maps are generally used to the efficient urban management tool. The density maps from political boundaries, however, were traditionally used to estimate an urban concentration, there is problems to apply directly to urban management decision making due to (i) the abrupt changes between boundaries and (ii) the inclusion of green areas and forests in these areas. The mass-preserving interpolation method, the Pycnophylactic interpolation, could provide more realistic density maps. In addition, the classified urban areas from satellite images corresponding years would turn out to be more reliable results since populations were only applied to urbanized areas. Even though the Pyconophylactic method makes the density larger, it would be useful to produce a general urban growth trend at large scale. Consequently, four different density maps are compared and reviewed for this study, and the cross-sectional analysis provided to glimpse of population density around the city center.

  • PDF

Analysis on the Accessibility of the Primary Medical Facilities in Jinju City (진주시 1차 의료시설의 접근성 분석)

  • Kim, Mi Song;Won, Tae Hong;Yoo, Hwan Hee
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.23 no.3
    • /
    • pp.49-55
    • /
    • 2015
  • Current medical delivery system in Korea has been distinguished into three types; primary medical facilities, secondary facilities, and tertiary facilities since 1989. This system prevents the waste of medical resources along with the maintenance of balance according to the medical treatment subjects. However, it is inevitable that the imbalance of the medical services among regions has been generated due to the concentration of the medical facilities on large cities. In this regard, this study attempted to evaluate the quality of the primary medical services, emphasizing accessibility and convenience targeting Jinju city, a small and medium-sized city, based on the distribution characteristics of the space. The study results show that cohesion index about the spatial distribution of the primary care facilities was 0~0.25. It conducted a correlation analysis between the location of the hospitals and users, based on the study results. Finally, it is demonstrated the correlation between the location of the hospitals and users tended to be low, while, the cohesion of the Oriental medicine clinics was high in other treatment subjects, and the accessibility to the Oriental medicine clinics was the highest because most Oriental medicine clinics were distributed to the places where users were many. However, on account that the locations of the medical facilities and users were varied in other treatment subjects except for the Oriental medicine clinics, problems were generated in terms of the accessibility. Therefore, it is judged that the preparation of the measures to improve the selection of lots in consideration of users, who use the primary medical services, is required.

Development and Inspection of the Ortho-Calc v1.0 Program for the Calculation of the Orthometric Correction (정사보정량 계산을 위한 Ortho-Calc v1.0 프로그램의 개발과 검증)

  • Lee, Suk Bae;Sim, Jung Min
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.23 no.3
    • /
    • pp.41-47
    • /
    • 2015
  • To determine the accurate height, it should be considered geometric height difference obtained by levelling as well as the physical height difference what so called orthometric correction. The orthometric correction amount is small enough to ignore at flatland but the amount is big at high mountains, so it should be considered to obtain accurate height at high mountains. But the calculation process is difficult and complex, not easy to calculate. So, to make the process easy using a user-friendly visual, a orthometric correction calculation program Ortho-Calc. v1.0 was developed in this study. This program was adopted the algorithm of Nassar and Hwang & Hsiao, and Strang Van Hees and it could be to selectivily calculate the correction amount. The inspection result exhibited high accuracy with the standard deviation of 0.024mm by the comparison of previous study. Therefore, This program Ortho-Calc. v1.0 developed in this study, will contribute orthometric correction calculation quickly and easily. And, if this program is widely popular, it could be expected to make a contribution the Benchmark's official height renewal using orthometric correction.

Assessing the Real-time Positioning Accuracy of Low-cost GPS Receiver using NTRIP-based Augmentation Service (Ntrip 기반 보정서비스를 활용한 저가 GPS 수신기의 실시간 측위 정확도 평가)

  • Lee, Yong Chang
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.23 no.3
    • /
    • pp.31-39
    • /
    • 2015
  • This paper presents the static and kinematic positioning accuracy by the real-time GPS positioning modes of the low-cost GPS receivers using NTRIP-based augmentation service. For this, acquires both the raw measurements data of the field tests by LEA 6T GPS module of u-blox AG, and correction communication via NTRIP caster with RTKLIB as an open source program for GNSS solution. With computing the positions of the check points and road tracks by six kinds of GPS positioning modes which are Single, SBAS, DGPS, PPP, RTK, and TCP/IP_RTK, compared these results to the reference position of the check points. The position error average and rmse of the static test by GPS L1 RTK surveying showed $N=0.002m{\pm}0.001m$, $E=0.004m{\pm}0.001m$ in horizontal plane, and $h=-0.116m{\pm}0.003m$ in vertical, these results are very closed to the coordinates with the geodetic receiver. Especially, in case of the kinematic test with obstacles located on both sides of road, the computed track with ambiguity fixing showed very similar trajectory considerably from VRS network RTK mode. And also, evaluate and verify the performance of the TCP/IP_RTK mode developed based on TCP/IP protocol.

Application of Geomorphological Features for Establishing the Preliminary Landslide Hazard (초기 산사태 위험도 구축을 위한 지형요소의 활용)

  • Cha, A Reum;Kim, Tai Hoon;Gang, Seok Koo
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.23 no.3
    • /
    • pp.23-29
    • /
    • 2015
  • Due to the characteristics of landslide disasters including debris flow, the rapid speed to downward and difficulty to respond or evacuate from them, it is imperative to identify their potential hazards and prepare the reduction plans. However, the current landslide hazards generated by a variety of methods has been raised its accuracy because of the complexity of input data and their analyses, and the simplification of the landslide model. The main objective of this study is, therefore, to evaluate the preliminary landslide hazard based on the identification of geomorphological features. Especially, two methodologies based on the statistics of the directional data, Vector dispersion and Planarity analyses, are used to find some relationships between geomorphological characteristics and the landslide hazard. Results show that both methods well discriminate geomorphological features between stable and unstable domains in the landslide areas. Geomorphological features are closely related to the landslide hazard and it is imperative to maximize their characteristics by adapting multiple models rather than individual model only. In conclusions, the mechanism of landslide is not determined solely by a simple cause but the complex natural phenomenon caused by the interactions of the numerous factors and it is of primary importance to require additional researches for the outbreaking mechanism that are based on various methodologies.