• Journal of Astronomy and Space Sciences
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• 제32권1호
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• pp.91-99
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• 2015

The Korean Solar Radio Burst Locator (KSRBL) is a solar radio spectrograph observing the broad frequency range from 0.245 to 18 GHz with the capability of locating wideband gyrosynchrotron bursts. Due to the characteristics of a spiral feed, the beam center varies in a spiral pattern with frequency, making a modulation pattern over the wideband spectrum. After a calibration process, we obtained dynamic spectra consistent with the Nobeyama Radio Polarimeter (NoRP). We compared and analyzed the locations of bursts observed by KSRBL with results from the Nobeyama Radioheliograph (NoRH) and Atmospheric Imaging Assembly (AIA). As a result, we found that the KSRBL provides the ability to locate flaring sources on the Sun within around 2'.

• 천문학회보
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• 제37권2호
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• pp.111.1-111.1
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• 2012

We examine the relationship between a type II radio burst that started from an unusually high frequency of 425 MHz (fundamental component) and an associated white-light coronal mass ejection on 2011 February 13. The radio burst had a drift rate of 2.5 MHz/sec, indicating a relatively high shock speed. From SDO AIA observations we find that a loop-like erupting front sweeps across high density coronal loops near the start time of the burst (17:34:15 UT). We find fragmented structures of the type II burst, which indicates the signature of the shock propagating through the multiple loops. The deduced distance of shock formation (0.06 Rs) from flare center and speed of the shock (1100 km $s^{-1}$) using the measured density from AIA/SDO observations are comparable to the height (0.05 Rs, from the solar surface) and speed (700 km $s^{-1}$) of the CME leading edge observed by STEREO/EUVI. We conclude that the type II burst could be onset even in the low corona (41 Mm or 0.06 Rs, above the solar surface) if a fast CME shock passes through the high density loops.

• 천문학회지
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• 제38권4호
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• pp.437-443
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• 2005

The Solar Radio Burst Locator (SRBL) is a spectrometer that can observe solar microwave bursts over a wide band (0.1-18 GHz) as well as detect the burst locations without interferometry or mechanical scanning. Its prototype has been operated at Owens Valley Radio Observatory (OVRO) since 1998. In this study, we have evaluated the capability of the SRBL system in flux and radio burst location measurements. For this, we consider 130 microwave bursts from 2000 to 2002. The SRBL radio fluxes of 53 events were compared with the fluxes from USAF/RSTN and the burst locations of 25 events were compared with the optical flare locations. From this study, we found: (1) there is a relatively good correlation (r = 0.9) between SRBL flux and RSTN flux; (2) the mean location error is about 8.4 arcmin and the location error (4.7 arcmin) of single source events is much smaller than that (14.9 arcmin) of multiple source events; (3) the minimum location error usually occurred just after the starting time of burst, mostly within 10 seconds; (4) there is a possible anti-correlation (r = -0.4) between the pointing error of SRBL antenna and the location error. The anti-correlation becomes more evident (r=-0.9) for 6 strong single source events associated with X-class flares. Our results show that the flux measurement of SRBL is consistent with that of RSTN, and the mean location error of SRBL is estimated to be about 5 arcmin for single source events.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.32.2-32.2
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• 2008

A major solar radio burst can disturb many kinds of radio instruments, including cellular phone, GPS, and radar. Korea Astronomy and Space Science Institute (KASI) is developing Korean Solar Radio Burst Locator (KSRBL) in collaboration with New Jersey Institute of Technology. KSRBL is a single dish radio spectrograph, which records the spectra of microwave (0.5 - 18 GHz) bursts with 1 MHz spectral resolution and 1 s time cadence, and locates their positions on the solar disk within 2 arcmin. Hardware manufacturing is almost completed including 4-channel digitizer/FPGA. The system is currently installed at Owens Valley Radio Observatory (OVRO), and test of the operation is in progress. It will be installed at KASI in 2009. We report current status and test results of KSRBL.

• 한국위성정보통신학회논문지
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• 제6권2호
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• pp.107-111
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• 2011

세계2차대전을 통해 태양폭발은 레이더시스템에 큰 영향을 주는 것으로 밝혀졌다. 1942년 2월 28일의 전파교란 현상은 태양활동의 극대기에 증가한 우주 광선(cosmic ray)에 의한 것이었다. 이러한 사실들이 밝혀지면서 태양폭발 및 태양 입자 활동에 관한 연구가 활발히 이루어졌다. 태양폭발이 우주선에 미치는 영향, 극 운행 비행기에 미치는 영향, 레이더 시스템에 미치는 영향, 무선통신시스템에 미치는 영향 등에 대한 연구가 다양하게 이루어 지고 있다. 본 논문에서는 지난 40여년 간의 태양전파 관측자료를 분석하여 태양폭발에 의해 무선통신에 미치는 영향과 태양활동주기간의 상관관계를 분석하였다.

• 천문학회보
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• 제43권1호
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• pp.52.2-53
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• 2018

A stationary Type IV (IVs) radio burst was observed on September 24, 2011. Observations from the Nançay RadioHeliograph (NRH) show that the brightness temperature (TB ) of this burst is extremely high, over 10^11K at 150 MHz and over 10^8K in general. The degree of circular polarization (q ) is between -60%~-100%, which means that it is highly left-handed circularly polarized. The flux-frequency spectrum follows a power-law distribution, and the spectral index is considered to be roughly -3~-4 throughout the IVs. Radio sources of this event are located in the wake of the coronal mass ejection and are spatially dispersed. They line up to present a formation in which lower-frequency sources are higher. Based on these observations, it is suggested that the IVs was generated through electron cyclotron maser emission.

• Journal of Astronomy and Space Sciences
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• 제33권3호
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• pp.197-205
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• 2016

We investigated two flares in the solar atmosphere that occurred on June 3, 2012 and July 6, 2012 and caused propagation of Moreton and EIT waves. In the June 3 event, we noticed a filament winking which presumably was caused by the wave propagation from the flare. An interesting feature of this event is that there was a reflection of this wave by a coronal hole located alongside the wave propagation, but not all of this wave was transmitted by the coronal hole. Using the running difference method, we calculated the speed of Moreton and EIT waves and we found values of 926 km/s before the reflection and 276 km/s after the reflection (Moreton wave) and 1,127 km/s before the reflection and 46 km/s after the reflection (EIT wave). In the July 6 event, this phenomenon was accompanied by type II and type III solar radio bursts, and we also performed a running difference analysis to find the speed of the Moreton wave, obtaining a value of 988 km/s. The speed derived from the analysis of the solar radio burst was 1,200 km/s, and we assume that this difference was caused by the different nature of the motions in these phenomena, where the solar radio burst was caused by the propagating particles, not waves.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1997년도 한국우주과학회보 제6권2호
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• pp.16.1-16
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• 1997

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.320-329
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• 1997

전파연구소 이천 분소에는 각각 세 개의 안테나로 30MHz∼2500MHz 대역의 태양전파를 관측할 수 있는 광대 역 태양전파분광시스템이 1995년에 설치되었다. 그 동안 태양전파 데이터를 수집 분석할 수 있는 소프트웨어가 없어 실질적인 관측이 이루어지지 않았으나 본 연구에 의해 운용 소프트웨어가 개발됨으로써 본격적인 태양전파관측 연구를 수행할 수 있게 되었다. 개발된 운용 소프트웨어를 실험 이용한 결과 1997년 11월 4일 06시경(UT)에 연속하여 발생한 3개의 TYPE III Burst에 대한 양질의 관측자료를 얻을 수 있었다. 본 논문에서는 전파연구소 이천 분소의 광대역 전파분광시스템을 소개하고 태양전파 데이터의 취득, 처리 및 분석을 위해 개발한 소프트웨어와 이를 통해 관측된 결과에 대하여 설명한다.

• 천문학회보
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• 제38권2호
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• pp.91.2-91.2
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• 2013

The Korean Solar Radio Burst Locator (KSRBL) is a solar radio spectrograph observing the frequency range between 0.245-18 GHz with the capability of locating the wideband gyrosynchrotron bursts. Its calibration process consists of antenna calibration, flux calibration, and demodulation. Antenna calibration is to determine the position, the width, and the peak value of the beam, flux calibration is to determine the conversion factor between the measured unit to the Solar Flux Unit (SFU), and demodulation is to determine the burst position and remove the modulation pattern. We introduce the current calibration software and some information that potential users may concern.