• Title/Summary/Keyword: ground station

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The Structure and Operation of KOMPSAT-II Memory (다목적실용위성 2호 메모리 구조와 운영)

  • 이종태;이상규;이상택;이도경
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.421-424
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    • 2003
  • The KOMPSAT-II has a MSC(Multi-Spectral Camera) payload for earth observatory. The image data acquired during the pass over the Korean Peninsula can be sent to the ground station directly. But the image data out of the contact range should be stored temporally for later transmission. The KOMPSAT-II has a device for this purpose called the DCSU(Data Compression and Storage Unit) and the DCSU also performs compression functions for saving storage space and transmission time to send image data to the ground station. In this paper, we'd like to introduce the DCSU memory structures and operation.

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Study of Short-Circuit Currents Around Dĕtmarovice Power Station

  • Ali, Shehab Abdulwadood
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.3
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    • pp.117-124
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    • 2014
  • The calculation of short-circuit currents is important for power systems operation and restoration, and for determining the means to protect human lives and properties. In this paper, a part of a power system network, around the D$\breve{e}$tmarovice power station in Czech Republic, was simulated by the well known program EMTP-ATPDraw (Electromagnetic Transients Program-Alternative Transient Program), and short-circuit currents and voltages were calculated at different points in the electric network and presented as a time function by the PlotXY program. Calculations were done just for phase-to-ground, and for the three-phase short-circuit at the Kun$\check{c}$ice substation. The results were important for determining the characteristics of the equipment required to withstand or break the short-circuit current; for this reason, the calculations were repeated using earth-fault resistances only for the case of busbar KUN shown in Figs. 5 and 6.

The Analysis on the relation between the Compression Method and the Performance of MSC(Multi-Spectral Camera) Image data

  • Yong, Sang-Soon;Choi, Myung-Jin;Ra, Sung-Woong
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.530-532
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    • 2007
  • Multi-Spectral Camera(MSC) is a main payload on the KOMPSAT-2 satellite to perform the earth remote sensing. The MSC instrument has one(1) channel for panchromatic imaging and four(4) channel for multi-spectral imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). The compression method on KOMPSAT-2 MSC was selected and used to match EOS input rate and PDTS output data rate on MSC image data chain. At once the MSC performance was carefully handled to minimize any degradation so that it was analyzed and restored in KGS(KOMPSAT Ground Station) during LEOP and Cal./Val.(Calibration and Validation) phase. In this paper, on-orbit image data chain in MSC and image data processing on KGS including general MSC description is briefly described. The influences on image performance between on-board compression algorithms and between performance restoration methods in ground station are analyzed and discussed.

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A Reinforcement Effect of Pile Foundation by Compaction Grouting System in Railroad Station Building (Compaction Grouting System에 의한 철도역사건물 파일기초보강효과)

  • Chun, Byung-Sik;Choi, Seung-Kwon;Do, Jong-Nam;Sung, Hwa-Don
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1364-1368
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    • 2006
  • By the countermeasure which is caused by with railroad station ground settlement it applied a CGS in each independent foundation. The effectiveness of the ground improvement and the bearing capacity of the compaction pile has been verified by the Cone Penetration Test(CPT) and Load Test. Test result show that penetration resistance and the cone friction force increased a lot and settlement 13.475mm as the standard settlement 40.0mm appeared at below. Also uniaxial compression test result $278kg/cm^2$ as the standard $150kg/cm^2$ appeared far a lot.

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Development of High Speed Satellite Data Acquisition System

  • Choi, Wook-Hyun;Park, Sang-Jin;Seo, In-Seok;Park, Won-Kyu
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.280-282
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    • 2003
  • The downlink data rates of the space-born payloads such as high-resolution optical cameras, synthetic aperture radars (SAR) and hyper-spectral sensors are being rapidly increased. For example, the image transmission rates of KOMPSAT-2 MSC(Multi-Spectral Camera) is 320Mbps even if on-board image compression scheme is used.[1] In the near future, the data rates are expected to be a level 500${\sim}$600Mbps because the required resolution will be higher and the swath width will be increased. This paper describes many techniques they enable 500Mbps data receiving and archiving system.

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A Study on High-Precision Digital Map Generation Using Ground LiDAR (지상 LiDAR를 이용한 고정밀 수치지도 생성에 관한 연구)

  • Choi, Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.2
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    • pp.125-132
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    • 2017
  • The slope of the road in the forest area has a characteristic of steep slope, so natural disasters such as slope collapse occur. The slope displacement observation technique according to landslide is being studied as a method to observe a wide area and a method to observe a small area. This is a study on high-precision digital map generation using ground LiDAR. It is possible to create a high - precision digital map by minimizing the US side using the 3D LiDAR in the steep slope area where the GPS and Total Station measurement are difficult in the maintenance of the danger slope area. It is difficult to objectively evaluate whether the contour lines generated by LiDAR are correct and it is considered necessary to construct a test bed for this purpose. Based on this study, if terrain changes such as landslides occur in the future, it will be useful for measuring slope displacement.

STATION-KEEPING FOR COMS SATELLITE BY ANALYTIC METHODS (해석적인 방법을 사용한 통신해양기상위성의 위치유지)

  • Kim Young-Rok;Kim Hae-Yeon;Park Sang-Young;Lee Byoung-Sun;Park Jae-Woo;Choi Kyu-Hong
    • Journal of Astronomy and Space Sciences
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    • v.23 no.3
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    • pp.245-258
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    • 2006
  • In this paper, an automation algorithm of analyzing and scheduling the station-keeping maneuver is presented for Communication, Ocean and Meteorological Satellite (COMS). The perturbation analysis for keeping the position of the geostationary satellite is performed by analytic methods. The east/west and north/south station-keeping maneuvers we simulated for COMS. Weekly east/west and biweekly north/south station-keeping maneuvers are investigated for a period of one year. Various station-keeping orbital parameters are analyzed. As the position of COMS is not yet decided at either $128.2^{\circ}E\;or\;116.0^{\circ}E$, both cases are simulated. For the case of $128.2^{\circ}E$, east/west station-keeping requires ${\Delta}V$ of 3.50m/s and north/south station-keeping requires ${\Delta}V$ of 52.71m/s for the year 2009. For the case of $116.0^{\circ}E,\;{\Delta}V$ of 3.86m/s and ${\Delta}V$ of 52.71m/s are required for east/west and north/south station-keeping, respectively. The results show that the station-keeping maneuver of COMS is more effective at $128.2^{\circ}E$.

Implementation and Validation of Earth Acquisition Algorithm for Communication, Ocean and Meteorological Satellite

  • Park, Sang-Wook;Lee, Young-Ran;Lee, Byoung-Sun;Hwang, Yoo-La;Lee, Un-Seob
    • Journal of Astronomy and Space Sciences
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    • v.28 no.4
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    • pp.345-354
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    • 2011
  • Earth acquisition is to solve when earth can be visible from satellite after Sun acquisition during launch and early operation period or on-station satellite anomaly. In this paper, the algorithm and test result of the Communication, Ocean and Meteorological Satellite (COMS) Earth acquisition are presented in case of on-station satellite anomaly status. The algorithms for the calculation of Earth-pointing attitude control parameters including those attitude direction vector, rotation matrix, and maneuver time and duration are based on COMS configuration (Eurostar 3000 bus). The coordinate system uses the reference initial frame. The constraint calculating available time-slot to perform the earth acquisition considers eclipse, angular separation, solar local time, and infra-red earth sensor blinding conditions. The results of Electronics and Telecommunications Research Institute (ETRI) are compared with that of the Astrium software to validate the implemented ETRI software.

Effects of Fucoxanthin Addition to Ground Chicken Breast Meat on Lipid and Colour Stability during Chilled Storage, before and after Cooking

  • Sasaki, Keisuke;Ishihara, Kenji;Oyamada, Chiaki;Sato, Akiyuki;Fukushi, Akihiko;Arakane, Tomohiro;Motoyama, Michiyo;Yamazaki, Makoto;Mitsumoto, Mitsuru
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.1067-1072
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    • 2008
  • Effects of fucoxanthin (FX), a major carotenoid in algae, on lipid peroxidation and meat colour in ground chicken breast meat were investigated. FX and/or ${\alpha}$-tocopherol (Toc) were added to ground samples at a content level of 200 mg/kg. The samples were subjected to a chilling storage test before and after cooking. In the storage test before cooking, neither FX nor Toc affected the thiobarbituric acid reactive substances (TBARS) on days 1 and 6, and FX decreased the L* value and increased the a* and b* values. In the storage test after cooking, both FX and Toc decreased TBARS values on days 1 and 6. FX decreased the L* value and increased the a* and b* values, similar to what occurred in the storage test before cooking. Based on these results, we concluded that FX is a potent ingredient for improvement of the appearance and shelf life of chicken meat and its products.

Performance Enhancement of a Satellite's Onboard Antenna Tracking Profile using the Ground Station Searching Method

  • Song, Young-Joo;Lee, Jung-Ro;Kang, Jihoon;Jeon, Moon-Jin;Ahn, Sang-Il
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.3
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    • pp.391-400
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    • 2016
  • In satellite operations, stable maneuvering of a satellite's onboard antenna to prevent undesirable vibrations to the satellite body is required for high-quality high-resolution images. For this reason, the onboard antenna's angular rate is typically minimized while still satisfying the system requirement that limits the speed of the onboard antenna. In this study, a simple yet effective method, called the ground station searching method, is proposed to reduce the angular rate of a satellite's onboard antenna. The performance of the proposed method is tested using real flight data from the KOMPSAT-3 satellite. Approximately 83% of arbitrarily selected real flight scenarios from 66 test cases show reductions in the onboard antenna's azimuth angular rates. Additionally, reliable solutions were consistently obtained within a reasonably acceptable computation time while generating an onboard antenna tracking profile. The obtained results indicate that the proposed method can be used in real satellite operations and can reduce the operational loads on a ground operator. Although the current work only considers the KOMPSAT-3 satellite as a test case, the proposed method can be easily modified and applied to other satellites that have similar operational characteristics.