• Title/Summary/Keyword: 준실시간

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NEAR REAL-TIME ESTIMATION OF GEOMAGNETIC LOCAL K INDEX FROM GYEONGZU MAGNETOMETER (경주 지자기관측소 자료를 이용한 준실시간 K 지수 산출에 관한 연구)

  • Choi, K.C.;Cho, K.S.;Moon, Y.J.;Kim, K.H.;Lee, D.Y.;Park, Y.D.;Lim, M.T.;Park, Y.S.;Lim, H.R.
    • Journal of Astronomy and Space Sciences
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    • v.22 no.4
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    • pp.431-440
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    • 2005

  • Local K-index is an indicator representing local geomagnetic activity in every 3 hour. For estimation of the local K-index, a reasonable determination of solar quiet curve (undisturbed daily variation of geomagnetic field) is quiet essential. To derive the solar quiet curve, the FMI method, which is one of representative algorithms, uses horizontal components (H and D) of 3 days magnetometer data from the previous day to the next day for a specific day. However, this method is not applicable to real time forecast since it always requires the next day data. In this study, we have devised a new method to estimate local K-index in near real-time by modifying the FMI method. The new method selects a recent quiet day whose $K_p$ indices, reported by NOAA/SEC are all lower than 3, and replace the previous day and the next day data by the recent quiet day data. We estimated 2,672 local K indices from Gyeongzu magnetometer in 2003, and then compared the indices with those from the conventional FMI method. We also compared the K indices with those from Kakioka observatory. As a result, we found that (1) K indices from the new method are nearly consistent with those of the conventional FMI method with a very high correlation (R=0.96); (2) onr local K indices also have a relatively high correlation (R=0.81) with those from Kakioka station. Our results show that the new method can be used for near real-time estimation of local K indices from Gyeongzu magnetometer.

  • https://doi.org/10.5140/JASS.2005.22.4.431 인용 PDF KSCI

Near Real-time Immediate Forecasting of Storm Surge Based on Typhoon Advisories (태풍 예경보에 근거한 폭풍해일 준실시간 즉각 예보)

  • Suh, SeungWon;Lee, HwaYoung;Kim, HyeonJeong;Park, JinSoo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.5
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    • pp.352-365
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    • 2012

  • A primary study on the rapid modeling of storm surge, which is one of typical coastal disasters, for immediate forecasting in conjunction with typhoon advisories is done and tested for the typhoons Bolaven, Tembin and Sanba which attacked to Korean Peninsula on August and September in this year 2012. Semi automatic rapid computations according to JTWC typhoon advisories were performed and uploaded to the web by models SLOSH in PC and ADCIRC in parallel clusters with 64 cores having 57k nodes encompassing the North-Western Pacific region. It only takes 1 and 2 hours from taking advisory to web uploading, respectively. By comparison with observed water surface elevations for the major tidal stations after Bolaven attack it shows within RMS error of 0.17~0.19 m for surge heights and only deviates 1 hour of peak surge time in ADCIRC model. Thus it is concluded that this approach provides a frame of near real-time immediate forecasting of storm surges with satisfactions.

  • https://doi.org/10.9765/KSCOE.2012.24.5.352 인용 PDF KSCI

Anomaly Detection of IGS Predicted Orbits for Near-Real-Time Positioning Using GPS (GPS기반 준실시간 위치추적을 위한 IGS 예측궤도력 이상 검출)

  • Ha, Ji-Hyun;Heo, Moon-Beom;Nam, Gi-Wook
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.953-961
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    • 2011

  • IGS (International GNSS Service) predicted orbits contained in IGS ultra-rapid orbits is suitable for real-time or near-real-time precise positioning. In this paper, we analyzed orbit anomalies of the IGS predicted orbits and detected the anomalies NANU (Current Notice Advisories to NAVSTAR Users) messages and IGS BRDC (Broadcast Ephemerides). As a results, the orbit anomalies of the predicted orbits were observed 93 times in 2010. In case of using the NANUs, we could get detection performance of 88% about the IGS predicted orbits's anomalies. And we could achieve 95% detection performance when the NANUs and BRDCs were used together.

  • https://doi.org/10.12673/jant.2011.15.6.953 인용 PDF KSCI

준실시간 고정밀 GPS 자료처리 자동화 시스템 구축

  • 하지현;박관동;박필호;임형철
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.33-38
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    • 2003

  • We automated high-accuracy data processing routines for various near-real-time GPS applications. The automated system was based on UNIX, and it uses GIPSY-OASIS II and ultra-rapid orbits which is updated twice a day and provided online. The highest error in the estimated site position was 2 cm and 5 cm in the horizontal and vertical directions, respectively. The mean 3-D position error about 2 cm.

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