• 제목/요약/키워드: Satellite data

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INTRODUCTION OF THE SIMC PROJECT

  • Chae, Gee-Ju;Cho, Seong-Ik;Park, Jong-Hyun;Jo, Kwan-Bok
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.356-359
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    • 2006
  • The high prices and lack of information for satellite images prevent researchers from studying remote sensing and most non-professional people can't have the simple and easy solutions for the manipulation of satellite images. 'Satellite Imagery Information Management Center'(SIMC) project which is promoted by ETRI (Electronics and Telecommunications Research Institute) from 2002 to 2005 in Korea have the purpose to provide the satellite images freely to the public domain and the solutions for the above mentioned problems. Our project have the following five systems; Data Acquisition System, Data Preservation System, Integrated Solution System, Technology Development System, Operation Plan System. Data Acquisition System collects the satellite images such as LANDSAT, IKONOS, etc. Data Preservation System consists of database which registers the diverse satellite images. Integrated Solution System gives the user of public domain for the web service which search, order and transfer the satellite images. Technology Development System has the many processing technologies for the satellite images. Finally, the Operation Plan system has the role to plan the future of our SIMC project. In this paper, we will give the result of SIMC Project for each five systems during the fast four years from 2002 to 2005.

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CONSTRUCTION OF AMSR-E LEVEL-1 PROCESSOR AND RETRIEVAL OF OCEAN PARAMETERS

  • Kim, Seung-Bum;Shin, Ji-Hyun;Im, Yong-Jo;Shin, Ji-Hyun;Park, Sung-Oak;Park, Seung-Hwan;Lee, Jong-Ju;Kim, Moon-Gyu;Park, Hae-Suk;Kim, Keum-Ran
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.828-830
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    • 2003
  • We have constructed a level-1 processor to generate brightness temperatures using the direct-broadcast data from the passive microwave radiometer onboard Aqua satellite. Although 50-minute half-orbit data, called a granule, are being routinely produced, to our knowledge, this is the first attempt to process about 10-minute long direct-broadcast data. We modified the processor designed for a granule to process the direct-broadcast data. After the modification, our brightness temperature product differs from the reference by 0.2K rms. Sea surface temperatures are retrieved to demonstrate the utility of AMSR-E.

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Dynamic Caching Routing Strategy for LEO Satellite Nodes Based on Gradient Boosting Regression Tree

  • Yang Yang;Shengbo Hu;Guiju Lu
    • Journal of Information Processing Systems
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    • 제20권1호
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    • pp.131-147
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    • 2024
  • A routing strategy based on traffic prediction and dynamic cache allocation for satellite nodes is proposed to address the issues of high propagation delay and overall delay of inter-satellite and satellite-to-ground links in low Earth orbit (LEO) satellite systems. The spatial and temporal correlations of satellite network traffic were analyzed, and the relevant traffic through the target satellite was extracted as raw input for traffic prediction. An improved gradient boosting regression tree algorithm was used for traffic prediction. Based on the traffic prediction results, a dynamic cache allocation routing strategy is proposed. The satellite nodes periodically monitor the traffic load on inter-satellite links (ISLs) and dynamically allocate cache resources for each ISL with neighboring nodes. Simulation results demonstrate that the proposed routing strategy effectively reduces packet loss rate and average end-to-end delay and improves the distribution of services across the entire network.

Management Information System of the Nanji Islands National Marine Reserve, China

  • Qingmei, XIAO;Huaguo, ZHANG;Changbao, ZHOU;Weigen, HUANG;Dongling, LI;Junhua, Ten
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.298-300
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    • 2003
  • A management information system of the Nanji Islands National Marine Reserve is designed and constructed based on method of integration of remote sensing and geographic information system (GIS). The system consists of two sub-systems, dynamic monitoring information system and general database system. The former is used for storage and manage fundamental geographical data (topographical and bathymetric map), satellite remote sensing data (IKONOS, SPOT, IRS, NOAA and SeaWiFS etc.) and multimedia data. The latter is used for storage and manage resource data (shellfish and alga etc.), environmental data (meteorological and hydrologic) and in situ data. As part of electronic government, this system will be submitted to local government for monitoring, management and decision.

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Evaluation performance of machine learning in merging multiple satellite-based precipitation with gauge observation data

  • Nhuyen, Giang V.;Le, Xuan-hien;Jung, Sungho;Lee, Giha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.143-143
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    • 2022
  • Precipitation plays an essential role in water resources management and disaster prevention. Therefore, the understanding related to spatiotemporal characteristics of rainfall is necessary. Nowadays, highly accurate precipitation is mainly obtained from gauge observation systems. However, the density of gauge stations is a sparse and uneven distribution in mountainous areas. With the proliferation of technology, satellite-based precipitation sources are becoming increasingly common and can provide rainfall information in regions with complex topography. Nevertheless, satellite-based data is that it still remains uncertain. To overcome the above limitation, this study aims to take the strengthens of machine learning to generate a new reanalysis of precipitation data by fusion of multiple satellite precipitation products (SPPs) with gauge observation data. Several machine learning algorithms (i.e., Random Forest, Support Vector Regression, and Artificial Neural Network) have been adopted. To investigate the robustness of the new reanalysis product, observed data were collected to evaluate the accuracy of the products through Kling-Gupta efficiency (KGE), probability of detection (POD), false alarm rate (FAR), and critical success index (CSI). As a result, the new precipitation generated through the machine learning model showed higher accuracy than original satellite rainfall products, and its spatiotemporal variability was better reflected than others. Thus, reanalysis of satellite precipitation product based on machine learning can be useful source input data for hydrological simulations in ungauged river basins.

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Development of Image Processing Software for Satellite Data

  • Chi, Kwang-Hoon;Suh, Jae-Young;Han, Jong-Kyu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.361-369
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    • 1998
  • Recently, the improvement of on-board satellite sensors covering hyperspectral image sensors, high spatial resolution sensors provide data on earth in diverse aspect. The application field relating remotely sensed data also varies depending on what type of job one wants. The various resolution of sensors from low to extremely high is also available on the market with a user defined specific location. The expense to purchase remote sensed data is going down compare to the cost it need past few years ago in terms of research or private use. Now, the satellite remote sensed data is used on the field of forecasting, forestry, agriculture, urban reconstruction, geology, or other research field in order to extract meaningful information by applying special techniques of image processing. There are many image processing packages available worldwide and one common aspect is that they are expensive. There need to be a advanced satellite data processing package for people who can not afford commercial packages to apply special remote sensing techniques on their data and produce valued-added product. The study was carried out with the purpose of developing a special satellite data processing package which covers almost every satellite produced data with normal image processing functions and also special functions needed on specific research field with friendly graphical user interface (GUI). And for the people with any background of remote sensing with windows platform.

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다중시기 위성영상의 무감독분류에 의한 갯벌의 입자 분포도 (Particulate Distribution Map of Tidal Flat using Unsupervised Classification of Multi-Temporary Satellite Data)

  • 정종철
    • 대한원격탐사학회지
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    • 제18권2호
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    • pp.71-79
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    • 2002
  • 본 연구는 현장조사에서 얻어진 갯벌의 퇴적물 입자조성과 동일시기의 위성영상에서 추출된 반사치를 이용하여 함평만 갯벌의 입자분포도를 제시하였다. Landsat TM 자료에서 추출된 갯벌 입자조성에 따른 스팩트럼이 분석되었고, 7개의 위성영상은 ISODATA 와 K-MEANS 방법으로 분류되었다. 무감독분류된 결과는 현장관측치에 의해 분류 정확도가 평가되었으며, ISODATA와 K-MEANS 방법의 분류 정확도는 84.3%와 85.7%이다. 다중시기 위성영상 분류 결과를 검증하기 위해 현장조사 자료에 의해 분류된 1999년 5월 TM 영상을 참조자료로 하여 다중시기의 영상분류 결과를 비교하였다.

MIL-STD-1553B 버스를 이용한 통신해양기상위성의 시스템 버스 설계 및 분석 (COMS System Bus Design and Analysis using MIL-STD-1553B)

  • 조영호
    • 전기학회논문지
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    • 제57권7호
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    • pp.1285-1289
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    • 2008
  • In this paper, we design COMS system bus that the 1553 Data Bus is able to link all the units of the satellite managed by the SCU using one Prime Data Bus and on Redundant Data Bus. Also we analyze MIL-STD-1553B bus load and relevant exchange memory budgets in system bus of the COMS satellite. This data is used in the satellite mission and software design by system engineer.

Accuracy evaluation of near-surface air temperature from ERA-Interim reanalysis and satellite-based data according to elevation

  • Ryu, Jae-Hyun;Han, Kyung-Soo;Park, Eun-Bin
    • 대한원격탐사학회지
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    • 제29권6호
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    • pp.595-600
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    • 2013
  • In order to spatially interpolate the near-surface temperature (Ta) values, satellite and reanalysis methods were used from previous studies. Accuracy of reanalysis Ta was generally better than that of satellite-based Ta, but spatial resolution of reanalysis Ta was large to use at local scale studies. Our purpose is to evaluate accuracy of reanalysis Ta and satellite-based Ta according to elevation from April 2011 to March 2012 in Northeast Asia that includes various topographic features. In this study, we used reanalysis data that is ERA-Interim produced by European Centre for Medium-Range Weather Forecasts (ECMWF), and estimated satellite-based Ta using Digital Elevation Meter (DEM), Normalized Difference Vegetation Index (NDVI), difference between brightness temperature of $11{\mu}m$ and $12{\mu}m$, and Land Surface Temperature (LST) data. The DEM data was used as auxiliary data, and observed Ta at 470 meteorological stations was used in order to evaluate accuracy. We confirmed that the accuracy of satellite-based Ta was less accurate than that of ERA-Interim Ta for total data. Results of analyzing according to elevation that was divided nine cases, ERA-Interim Ta showed higher accurate than satellite-based Ta at the low elevation (less than 500 m). However, satellite-based Ta was more accurate than ERA-Interim Ta at the higher elevation from 500 to 3500 m. Also, the width of the upper and lower quartile appeared largely from 2500 to 3500 m. It is clear from these results that ERA-Interim Ta do not consider elevation because of large spatial resolution. Therefore, satellite-based Ta was more effective than ERA-Interim Ta in the regions that is range from 500 m to 3500 m, and satellite-based Ta was recommended at a region of above 2500 m.

KASS 활용을 위한 위성기반 보강항법시스템(SBAS) 비규격 데이터 전송 방법 연구 (SBAS Non-Standard Data Transmission Method for Korea Augmentation Satellite System Applications)

  • 박재익;이은성;허문범;남기욱
    • 한국통신학회논문지
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    • 제41권12호
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    • pp.1861-1867
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    • 2016
  • 지난 2014년 한국형 SBAS (satellite based augmentation system)인 KASS (korea augmentation satellite system) 개발 구축 사업을 본격적으로 착수하였다. SBAS는 항공용으로 제정된 규격이지만, 비항공 분야에서도 활용이 가능하다. SBAS 규격으로 정해져 있는 메시지에 전송되는 정보의 종류 및 내용이 한정되어 있다. 전송되는 정보를 통해 센티미터 수준의 고정밀 위치 정보가 요구되는 분야에서 활용하기에는 정확도 수준이 낮기 때문에 추가적인 정보 제공이 필요하다. 비항공 분야에서 활용되는 정보를 항공기 항법에 영향을 주지 않으면서 안전하게 전송하기 위해서는 이에 대한 방법이 필요하다. 따라서, 이 논문에서는 항공용 SBAS 수신기에 대한 안전을 확보하면서 비항공 분야에서 활용할 수 있는 비규격 SBAS 데이터를 전송하는 방법에 대해 고찰하였다.