• Title/Summary/Keyword: Remote Sensing

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A Study on the Observation of Soil Moisture Conditions and its Applied Possibility in Agriculture Using Land Surface Temperature and NDVI from Landsat-8 OLI/TIRS Satellite Image (Landsat-8 OLI/TIRS 위성영상의 지표온도와 식생지수를 이용한 토양의 수분 상태 관측 및 농업분야에의 응용 가능성 연구)

  • Chae, Sung-Ho;Park, Sung-Hwan;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.931-946
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    • 2017
  • The purpose of this study is to observe and analyze soil moisture conditions with high resolution and to evaluate its application feasibility to agriculture. For this purpose, we used three Landsat-8 OLI (Operational Land Imager)/TIRS (Thermal Infrared Sensor) optical and thermal infrared satellite images taken from May to June 2015, 2016, and 2017, including the rural areas of Jeollabuk-do, where 46% of agricultural areas are located. The soil moisture conditions at each date in the study area can be effectively obtained through the SPI (Standardized Precipitation Index)3 drought index, and each image has near normal, moderately wet, and moderately dry soil moisture conditions. The temperature vegetation dryness index (TVDI) was calculated to observe the soil moisture status from the Landsat-8 OLI/TIRS images with different soil moisture conditions and to compare and analyze the soil moisture conditions obtained from the SPI3 drought index. TVDI is estimated from the relationship between LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index) calculated from Landsat-8 OLI/TIRS satellite images. The maximum/minimum values of LST according to NDVI are extracted from the distribution of pixels in the feature space of LST-NDVI, and the Dry/Wet edges of LST according to NDVI can be determined by linear regression analysis. The TVDI value is obtained by calculating the ratio of the LST value between the two edges. We classified the relative soil moisture conditions from the TVDI values into five stages: very wet, wet, normal, dry, and very dry and compared to the soil moisture conditions obtained from SPI3. Due to the rice-planing season from May to June, 62% of the whole images were classified as wet and very wet due to paddy field areas which are the largest proportions in the image. Also, the pixels classified as normal were analyzed because of the influence of the field area in the image. The TVDI classification results for the whole image roughly corresponded to the SPI3 soil moisture condition, but they did not correspond to the subdivision results which are very dry, wet, and very wet. In addition, after extracting and classifying agricultural areas of paddy field and field, the paddy field area did not correspond to the SPI3 drought index in the very dry, normal and very wet classification results, and the field area did not correspond to the SPI3 drought index in the normal classification. This is considered to be a problem in Dry/Wet edge estimation due to outlier such as extremely dry bare soil and very wet paddy field area, water, cloud and mountain topography effects (shadow). However, in the agricultural area, especially the field area, in May to June, it was possible to effectively observe the soil moisture conditions as a subdivision. It is expected that the application of this method will be possible by observing the temporal and spatial changes of the soil moisture status in the agricultural area using the optical satellite with high spatial resolution and forecasting the agricultural production.

CAS 500-1/2 Image Utilization Technology and System Development: Achievement and Contribution (국토위성정보 활용기술 및 운영시스템 개발: 성과 및 의의)

  • Yoon, Sung-Joo;Son, Jonghwan;Park, Hyeongjun;Seo, Junghoon;Lee, Yoojin;Ban, Seunghwan;Choi, Jae-Seung;Kim, Byung-Guk;Lee, Hyun jik;Lee, Kyu-sung;Kweon, Ki-Eok;Lee, Kye-Dong;Jung, Hyung-sup;Choung, Yun-Jae;Choi, Hyun;Koo, Daesung;Choi, Myungjin;Shin, Yunsoo;Choi, Jaewan;Eo, Yang-Dam;Jeong, Jong-chul;Han, Youkyung;Oh, Jaehong;Rhee, Sooahm;Chang, Eunmi;Kim, Taejung
    • Korean Journal of Remote Sensing
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    • v.36 no.5_2
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    • pp.867-879
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    • 2020
  • As the era of space technology utilization is approaching, the launch of CAS (Compact Advanced Satellite) 500-1/2 satellites is scheduled during 2021 for acquisition of high-resolution images. Accordingly, the increase of image usability and processing efficiency has been emphasized as key design concepts of the CAS 500-1/2 ground station. In this regard, "CAS 500-1/2 Image Acquisition and Utilization Technology Development" project has been carried out to develop core technologies and processing systems for CAS 500-1/2 data collecting, processing, managing and distributing. In this paper, we introduce the results of the above project. We developed an operation system to generate precision images automatically with GCP (Ground Control Point) chip DB (Database) and DEM (Digital Elevation Model) DB over the entire Korean peninsula. We also developed the system to produce ortho-rectified images indexed to 1:5,000 map grids, and hence set a foundation for ARD (Analysis Ready Data)system. In addition, we linked various application software to the operation system and systematically produce mosaic images, DSM (Digital Surface Model)/DTM (Digital Terrain Model), spatial feature thematic map, and change detection thematic map. The major contribution of the developed system and technologies includes that precision images are to be automatically generated using GCP chip DB for the first time in Korea and the various utilization product technologies incorporated into the operation system of a satellite ground station. The developed operation system has been installed on Korea Land Observation Satellite Information Center of the NGII (National Geographic Information Institute). We expect the system to contribute greatly to the center's work and provide a standard for future ground station systems of earth observation satellites.

원격탐사 자료 공공 활용을 위한 한-유럽 국제협력

  • Kim, Yun-Su;Lee, Gwang-Jae;Triebnig, Gerhard;Hoersch, Bianca
    • Aerospace Engineering and Technology
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    • v.4 no.2
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    • pp.220-229
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    • 2005
  • The Earth observation imagery from satellite provide valuable informations for the central government, local governments and diverse public organizations. The analysis of applications and data, which are sold by commercial distributors of Earth observation satellite data, shows this phenomenon clearly. The Government of Republic of Korea established and carried out a national space development plan to meet the national needs for remotely sensed imagery. After this national space development plan and on behalf of Korean government KARI has developed and launched successfully the KOMPSAT-1 and operates it up to now. KARI is now to launch by the end of year 2005 another optical remote sensing satellite with very high resolution and named as KOMPSAT-2. For the application of such very high resolution remotely sensed data the product validation should be done carefully and this product validation require lots of ancillary data such as in-situ measurements. For the purpose of diverse ancillary data acquisition joint work with other nations, related institutes and international bodies is essential. In this paper the status of Korean European Cooperations will be introduced, which are derived by KARI, ARCS and ESA for the wide use of KOMPSAT data in Europe.

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Quantification of Soil Properties using Visible-NearInfrared Reflectance Spectroscopy (가시·근적외 분광 스펙트럼을 이용한 토양 이화학성 추정)

  • Choe, Eunyoung;Hong, S. Young;Kim, Yi-Hyun;Song, Kwan-Cheol;Zhang, Yong-Seon
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.6
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    • pp.522-528
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    • 2009
  • This study focused on establishing prediction models using visible-near infrared spectrum to simultaneously detect multiple components of soils and enhancing the performance quality by suitably transformed input spectra and classification of soil spectral types for prediction model input. The continuum-removed spectra showed significant result for all cases in terms of soil properties and classified or bulk predictions. The prediction model using classified soil spectra at an absorption peak area around 500nm and 950nm efficiently indicating soil color showed slightly better performance. Especially, Ca and CEC were well estimated by the classified prediction model at $R^{2}$ > 0.8. For organic carbon, both classified and bulk prediction model had a good performance with $R^{2}$ > 0.8 and RPD> 2. This prediction model may be applied in global soil mapping, soil classification, and remote sensing data analysis.

The status and future of the geomatics - about satellite geodesy and remote sensing (공간정보기술의 현황 및 전망 - 위성측지 및 원격탐사를 중심으로)

  • 안철호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2002.04a
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    • pp.3-10
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    • 2002
  • 요즘 측량분야에서 Geomatics 또는 Geoinformatics라는 새로운 용어가 대두되고 있다. 해외의 유수 기관 및 대학교에서도 측량이라는 학과명 또는 기관명을 Geomatics라는 용어로 교체하고 있으며, 이는 측량분야의 다양화와 학제간 연구수행의 필요성을 반영하는 것이다. 최근 45로 일컬어지는 GPS, 원격탐사(RS), GIS, ITS의 경우 각기 독자적인 영역을 구축하기보다는 상호 보완적인 역할을 하며 통합되어 가는 추세이다. 1950년대에 기본적인 위성관측기술 및 계산 기술의 개발을 시작으로 1980년대에 이르러서는 위성 기술은 측지학 및 측량 분야에 적용되기 시작했다. 그 대표적인 것이 GPS(Global Positioning System)로 기존의 천체측정학 방식을 대체하는 유용한 위치결정 수단으로 사용되기 시작했다. DNSS로부터 시작된 GPS는 측지 측량분야, 지구물리학분야, 항법 및 교통, GIS Mapping, 기상 및 해양, 재난 및 레저, 인공위성 궤도결정 등 다양한 분야에 적용되었으며, 특히 2000년 5월 1일 SA가 해제되면서 그 활용도는 더욱 증가하고 있다. 위성원격탐사의 경우 초창기에 중ㆍ저해상도의 다중분광영상에서 시작하여 그 해상도가 꾸준히 향상되어 오늘날 0.61 미터급 고해상도 위성인 QuickBird 위성이 발사되어 운용 중에 있다. 위성영상의 공간해상도, 분광해상도, 방사해상도는 향후 계속 향상될 것이며 이에 따른 방대한 데이터의 처리 문제 및 하드웨어/소프트웨어 지원에 대한 연구가 수반되어야 할 것이다. GPS 및 원격탐사(RS)는 더 이상 독자적인 영역으로서가 아니라 Geomatics를 이루는 중요한 분야로서 타 시스템과의 보완적인 관계로서 통합되어 나갈 것이다. 이를 위해서는 공간정보에 대한 표준화 및 데이터 처리, 통합, 시스템 구축을 위한 기술적 연구가 계속 진행되어야 할 것이다.분 공부상면적보다 늘어났다. 2. 좌표의 이동량이 일률적이지 못하므로 기초점에 대한 문제라고 생각되며, 따라서 도해지적을 수치지적으로 전환함에 있어서 가장 우선되어야 할 사항이 기초점 정비라 하겠다.승이 뚜렷하였다. 따라서 비파 착즙액 첨가 기능성 yoghurt 제조시 비파 착즙액을 10% 첨가하여 혼합 starter로 Str. thermophilus와 Lac. acidophilus 혼합균주를 사용하는 것이 이들 유산균의 증식에 가장 적합한 것으로 나타났다.타났다..297, 0.293, 0.205에서 50일 경과 후 0.612, 0.472, 0.898로 비살균에서 높은 값을 보였다. 따라서 비살균의 경우 저장말기에 TBA값이 높아지는 경향을 보였다. 5. L값은 살균처리의 경우 저장 30일 이후 약간 어두워지는 경향을 보였고, 121$^{\circ}C$ 살균처리에서 높은 값을 보였다. 대체로 저장온도가 높고 저장기간이 길어질수록 약간 밝아지는 경향을 보였다. 적색도는 인삼 첨가구의 경우 상온 및 냉장저장에서 10$0^{\circ}C$ 살균이 121$^{\circ}C$ 처리구 보다 약간 높은 값을 보였다. 저장기간에 따른 적색도의 변화는 인삼과 송이 첨가구에서 비교적 안정적이었다. 황색도는 상온 및 냉장저장에서 저장기간에 따라 약간 감소하는 경향을 보인 후 상온저장 50일 째, 냉장 60일 째 가장 높게 나타났다. 121$^{\circ}C$ 살균처리구가 10$0^{\circ}C$ 처리구보다 약간 높은 경향을 보였다.^{\circ}C$$,에서는 20시간 가열시 0.706$\mu\textrm{g}$/kg으로 가장 높게 생성된 후 서서히 감소하였다. 그러나 산값과 공액이중산값은 계속 증가하는 양상을 나타냈다. 즉 B(a)

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Influence of Grid Cell Size and Flow Routing Algorithm on Soil-Landform Modeling (수치고도모델의 격자크기와 유수흐름 알고리듬의 선택이 토양경관 모델링에 미치는 영향)

  • Park, S.J.;Ruecker, G.R.;Agyare, W.A.;Akramhanov, A.;Kim, D.;Vlek, P.L.G.
    • Journal of the Korean Geographical Society
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    • v.44 no.2
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    • pp.122-145
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    • 2009
  • Terrain parameters calculated from digital elevation models (DEM) have become increasingly important in current spatially distributed models of earth surface processes. This paper investigated how the ability of upslope area for predicting the spatial distribution of soil properties varies depending on the selection of spatial resolutions of DEM and algorithms. Four soil attributes from eight soil-terrain data sets collected from different environments were used. Five different methods of calculating upslope area were first compared for their dependency on different grid sizes of DEM. Multiple flow algorithms produced the highest correlation coefficients for most soil attributes and the lowest variations amongst different DEM resolutions and soil attributes. The high correlation coefficient remained unchanged at resolutions from 15 m to 50 m. Considering decreasing topographical details with increasing grid size, we suggest that the size of 15-30 m may be most suitable for soil-landscape analysis purposes in our study areas.

Multi-Spectral Reflectance of Warm-Season Turfgrasses as Influenced by Deficit Irrigation (난지형 잔디의 가뭄 스트레스 상태로 인한 멀티스팩트럴 반사광 연구)

  • Lee, Joon-Hee;Trenholm, Laurie. E.;Unruh, J. Bryan
    • Asian Journal of Turfgrass Science
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    • v.22 no.1
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    • pp.1-12
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    • 2008
  • Remote sensing using multispectral radiometry may be a useful tool to detect drought stress in turf. The objective of this research was to investigate the correlation between drought stress and multispectral reflectance (MSR) from the turf canopy. St. Augustinegrass (Stenotaphrum secundatum[Walt.] Kuntze.) cultivars 'Floratam' and 'Palmetto', 'SeaIsle 1' seashore paspalum Paspalum vaginatum Swartz.), 'Empire' zoysiagrass (Zoysia japonica Steud.), and 'Pensacola' bahiagrass (Paspalum notatumFlugge) were established in lysimeters in the University of Florida Envirotron greenhouse facility in Gainesville. Irrigation was applied at 100%, 80%, 60%, or 40% of evapotranspiration (ET). Weekly evaluations included: a) shoot quality, leaf rolling, leaf firing b) soil moisture, chlorophyll content index; c) photosynthesis and d) multispectral reflectance. All the measurements were correlated with MSR data. Drought stress affected the infrared spectral region more than the visible spectral region. Reflectance sensitivity to water content of leaves was higher in the infrared spectral region than in the visible spectral region. Grasses irrigated at 100% and 80% of ET had no differences in normalized difference vegetation indices (NDVI), leaf area index (LAI), and stress indices. Grasses irrigated at 60% and 40% of ET had differences in NDVI, LAI, and stress indices. All measured wavelengths except 710nm were highly correlated (P < 0.0001) with turf visual quality, leaf firing, leaf rolling, soil moisture, chlorophyll content index, and photosynthesis. MSR could detect drought stress from the turf canopy.

Analysis of Temperature Profiles by Land Use and Green Structure on Built-up Area (시가화지역 토지이용 및 녹지구조에 따른 온도변화 연구)

  • Hong Suk-Rwan;Lee Kyong-Jae;Han Bong-Ho
    • Korean Journal of Environment and Ecology
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    • v.19 no.4
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    • pp.375-384
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    • 2005
  • This study was conducted selecting 44 places with a block unit subject to urban area in Gangnam-gu, to analyze a temperature change according to land use and green structure. In this study, it was used the broad-wide urban temperature, supported by Landset TM and ETM+ satellite image 6scene(1999${\~}$2002). The result of the research, the land use pattern has slightly influence on a temperature change of urban area. The result from correlation analysis between temperature and the factors affected by land cover type, such as building-to-land ratio(A correlation coefficient is 0.368${\~}$0.709) have positive correlation and green area ratio(a correlation coefficient is -0.551${\~}$-0.860) have negative correlation. The result from correlation analysis between temperature and green capacity of the land, crown projection area ratio, each factor have negative correlation with temperature, as showing that a correlation coefficient of green capacity of the land is -0.577(June 2006)${\~}$-0.882(June 1999) and crown projection area ratio's is -0.549(June 2001)${\~}$-0.817(June 1999). The result of the regression analysis for establishing urban area temperature change prediction model showed that green capacity of the land of the explanation variable was accepted.

An Assessment of Landscape Ecological Value of Greenbelt Areas in the Seoul Metropolitan Area (수도권 개발제한구역의 경관생태학적 가치평가)

  • Oh, Kyushik;Park, Jihye;Lee, Dongwoo
    • Journal of Environmental Impact Assessment
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    • v.20 no.6
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    • pp.867-878
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    • 2011
  • Development restriction areas (greenbelt areas) of Korea were recognized in 1970 as a means to control urban sprawl and conserve the natural environment. Although there have been some achievements, for a long time many planners and residents have requested a redefining of the green belt due to individual property rights restrictions and urban management problems. In fact, a lot of the greenbelt area is being destroyed by urban development. Therefore, conservation of ecological spaces in the green belt is needed to maintain urban naturalness. In this regard, this study suggests efficient methods to manage the greenbelt through the adoption of a landscape ecological value assessment. The greenbelt of the Seoul Metropolitan Area (SMA) is represented as the case study because there has been mounting pressure to develop the area in Korea. In this study, the assessment of the landscape ecology in the greenbelt area focuses on landscape structure and function. The assessment consists of the following steps: First, patches were derived by NDVI analysis using landsat remote sensing data. Second, characteristics of the patches were quantified by analyzing the landscape structure, such as patch size and shape index. Lastly, the gravity model and least cost path analysis to assess connectivity were applied to evaluate the landscape function in the green belt areas. The assessment result showed that 48.45% of green belt area should be conserved to maintain ecological stability and function. Moreover, major ecological networks were identified near the large patches in the northern and southern areas. However, relative low ecological values were identified in the western part of the green belt area due to the lack of green spaces. Furthermore, some development plans in the green belt were also identified near the conservation area. Based on these results, the restoration needed areas to enhance ecological value in green belt were displayed. This study suggests efficient management of the greenbelt area, which is disappearing as a result of urban development. The area for conservation chosen in this study should be managed carefully in urban planning. Finally, the results of this study can be used in green belt polices and plans for the promotion of ecological naturalness and stability.

Unsupervised Classification of Landsat-8 OLI Satellite Imagery Based on Iterative Spectral Mixture Model (자동화된 훈련 자료를 활용한 Landsat-8 OLI 위성영상의 반복적 분광혼합모델 기반 무감독 분류)

  • Choi, Jae Wan;Noh, Sin Taek;Choi, Seok Keun
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.4
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    • pp.53-61
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    • 2014
  • Landsat OLI satellite imagery can be applied to various remote sensing applications, such as generation of land cover map, urban area analysis, extraction of vegetation index and change detection, because it includes various multispectral bands. In addition, land cover map is an important information to monitor and analyze land cover using GIS. In this paper, land cover map is generated by using Landsat OLI and existing land cover map. First, training dataset is obtained using correlation between existing land cover map and unsupervised classification result by K-means, automatically. And then, spectral signatures corresponding to each class are determined based on training data. Finally, abundance map and land cover map are generated by using iterative spectral mixture model. The experiment is accomplished by Landsat OLI of Cheongju area. It shows that result by our method can produce land cover map without manual training dataset, compared to existing land cover map and result by supervised classification result by SVM, quantitatively and visually.