• 대한원격탐사학회지
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• 제30권5호
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• pp.559-570
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• 2014

위성 탑재 라이다 시스템이 관측하는 후방산란 신호는 대기 에어러솔의 3차원 공간적인 분포 특성 및 시간적인 변화를 탐지할 수 있게 한다. 본 연구에서는 Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation(CALIPSO) 위성에 탑재된 Cloud-Aerosol LIDAR with Orthogonal Polarization(CALIOP) 라이다 관측자료를 이용하여 2012년 한 해 동안의 동북아시아 지역(북위 20도 - 50도, 동경 110 도 - 140 도)의 대기 에어로졸의 시공간 분포를 분석하였다. 입자 소산계수와 편광소멸도의 통계 분석으로부터 각 고도별 에어러솔 입자의 광학 특성정보를 분석하였고, 각 계절별 에어러솔 광학 특성값의 연직분포정보를 정량화할 수 있었다. 또한, 편광소멸도 자료는 연중 0.5 이상의 큰 값을 보이고 있어 지역 대기에는 비구형성 입자에 의한 영향이 많이 받고 있음을 알 수 있었다. 본 연구는 지역적 규모의 3차원 에어러솔 분포 정보에 대한 기초연구로서, 향후 추가 자료 조사를 통하여 보다 다양한 이벤트성 사례와 에어러솔 기후학적 정보를 생산할 것이다.

• 한국수자원학회논문집
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• 제46권5호
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• pp.465-476
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• 2013

방출장파복사량은 수치예보모형, 수문모형, 증발산 등에 사용되는 인자로 지구의 에너지 균형을 이해하는데 필수적이다. 현재 국내외에서는 이를 정확하게 관측하기가 어려우며, 또한 공간적인 제약이 따른다. 따라서, 본 연구에서는 원격탐사 기술을 적용함으로써 지상관측의 단점을 보완하기 위해 정지궤도 위성인 Communication, Ocean and Meteorological Satellite (COMS)를 사용하여 방출장파복사량(Outgoing Longwave Radiation, $R_{lu}$ )를 계산하였다. 이 자료의 검증을 위해 유량조사사업단에서운영 관리하는 청미천/설마천 Flux Tower의 자료를 사용하여 계산된 $R_{lu}$ 와 MODIS 위성자료를 사용하여 계산된 $R_{lu}$ 를 비교 및 검증하였다. 전반적으로 COMS의 자료가 높은 상관계수를 나타내어 COMS의 사용가능성을 보여주었다. 이러한 결과를 바탕으로 향후 COMS를 이용한 증발산 산정 연구를 할 계획이다.

• 대한원격탐사학회지
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• 제35권5_2호
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• pp.851-859
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• 2019

천리안(COMS, Communication, Ocean, and Meteorological Satellite) 위성은 한반도를 15분마다 촬영하지만, 관측 채널의 한계로 강우 추정 시 과소 추정하는 경향이 있어 풍수해 발생시 활용하기 어려웠다. 따라서 본 연구에서는 천리안 위성과 GPM(Global Precipitation Measurement) 위성자료를 함께 이용하여 한반도 풍수해 발생시 활용할 수 있는 위성기반 강우추정 기술을 개발하였다. 천리안 위성과 GPM 위성의 시간 공간 해상도를 일치시키고 GPM 위성의 IMERG 자료를 통해 강우추정 정확도를 향상시킨 결과, 종관기상 관측값(ASOS)간의 상관계수가 0.7 이상으로 나타나 기존 천리안 위성 자료만을 이용한 강우추정 기술보다 정확한 결과를 도출하였다. 향후 천리안 위성의 후속 위성인 천리안 2A호(GK-2A)를 활용할 경우 보다 정확한 기상정보가 제공될 예정이므로, 미계측 지역에 대한 재난관리 활용성이 확대될 것으로 기대된다.

• 천문학논총
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• 제27권4호
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• pp.161-164
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• 2012

We performed a spectroscopic survey for cometary volatiles with the Infrared Camera onboard the Japanese infrared satellite AKARI. The observations were carried out in the near-infrared wavelength range in the period from 2008 June to 2010 January. In this paper, we summarize the observations and results of the AKARI survey for the mixing ratios of major volatiles in comets. We derived the $2.5-5{\mu}m$ spectra of 18 comets including both Oort cloud comets and Jupiter-family comets. Prominent emission bands in the observed spectra are the fundamental vibrational bands of water ($H_2O$) at $2.7{\mu}m$ and carbon dioxide ($CO_2$) at $4.3{\mu}m$. The fundamental vibrational band of carbon monoxide (CO) at $4.7{\mu}m$ and the broad emission feature probably related to C-H bearing molecules can also be recognized around the $3.4-3.5{\mu}m$ region in some comets. We detect $CO_2$ in 17 out of 18 comets, and derived gas production rate ratios of $CO_2$ with respect to $H_2O$ in 17 comets. We detect a reliable CO emission band only in three of the comets. Our data set provides the largest homogeneous database of $CO_2/H_2O$ ratios in comets obtained so far.

• 천문학회지
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• 제38권2호
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• pp.69-72
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• 2005

The FIMS (Far-ultraviolet IMaging Spectrograph; also known as SPEAR, Spectroscopy of Plasma Evolution from Astrophysical Radiation) is the primary payload of the STSAT-1, the first Korean science satellite, which was launched in September, 2003. The FIMS performs spectral imaging of diffuse far-ultraviolet emission with the unprecedented wide field of view and the relatively good spectral resolution. We present far-ultraviolet spectral observations of highly ionized interstellar medium including supernova remnants, superbubbles, soft X-ray shadows, and the molecular hydrogen fluorescent emission lines. The FIMS has detected He II, C III, 0 III, O IV, Si IV, O VI, and $H_2$ fluorescent emission lines. The emission lines arise in shocked or thermally heated and in photo-ionized gases. We present an overview of the FIMS instrument and its initial observational results.

• 한국정보통신학회논문지
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• 제4권5호
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• pp.985-996
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• 2000

해안 지역에서 해양으로부터 들어오는 중규모 정도의 강수는 단기 예보를 위하여 원격 탐사에 의한 실시간 관측이 이루어져야 한다. 그러나 위성 관측은 강수를 상세히 묘사하지 못하기 때문에 레이더를 이용한 원거리관측이 요구된다. 본 연구에서는 레이더로 관측된 자료가 강수역을 정확하게 정량화 할 수 있도록 원거리 관측자료의 보정을 논의한다. 반사도의 연직 변화에 기인한 오차는 평균 분포나 통계적 방법으로 그리고 반사도의 감쇠 효과는 반복 편광법으로 보정될 수 있다. 이 같은 다양한 보정을 통하여 레이더로 관측된 원거리 자료를 유용화할 수 있다.

• Journal of Astronomy and Space Sciences
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• 제34권2호
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• pp.111-118
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• 2017

A ultra low frequency (ULF) wave, Pi2, has been reported to occur during periods of extremely quiet magnetospheric and solar wind conditions. And no statistical study on the Pi2 has been performed during extremely quiet conditions, using satellite observations to the author's knowledge. Also Pi2 pulsations in the space fluxgate magnetometers near perigee failed to attract scientist's attention previously. In this paper, Pi2 pulsations detected by the Van Allen probe satellites (VAP-A & VAP-B) were investigated statistically. During the period from October 2012 to December 2014, ninety six Pi2 events were identified using VAP when Kp = 0 while using Kakioka (KAK, L = 1.23) as a reference ground station. Seventy five events had high coherence between VAP-Bz and H components at KAK station. As a result, it was found that 77 % of the events had power spectra between 5 and 12 mHz, which differs from the regular Pi2 band range of from 6.7 to 25 mHz. In addition, it was shown that it is possible to observe Pi2 pulsations from space fluxgate magnetometers near perigee. Twenty two clean Pi2 pulsations were found where L < 4 and four examples of Pi2 oscillations at different L shells are presented in this paper.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.152-153
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• 2004

The growth rate of atmospheric $CO_2$ undergoes significant interannual variability, largely due to temporal variability of partitioning of $CO_2$ between terrestrial biosphere and ocean. In the present paper, as a follow-up to the work by Lee et al. [1], we estimated the year-to-year variability in net global air-sea $CO_2$ fluxes between 1982 and 2003 from observed changes in wind speed and estimated changes in ${\Delta}pCO_2$ Changes in $pCO_{25W}$ were inferred from global records of sea surface temperature (SST) anomalies and seasonally varying SST dependence of $pCO_{25W}$. The modeled interannual variability of $\pm0.2\;Pg\;C\;yr^{-1}\;(1{\sigma})$ from the present work is significantly smaller than the values deduced from atmospheric observations of $^{1.3}CO_2/CO_2$ in conjunction with different atmospheric transport models, but it is closer to the recent estimates inferred from a 3-D ocean biogeochemical model and atmospheric transport models constrained with extensive observations of atmospheric $CO_2$.

• 천문학회보
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• 제42권2호
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• pp.49.3-50
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• 2017

There have been recent studies which revealed a tendency that thermal inertia decreases with the size of asteroidal bodies, and suggestions that thermal inertias of cometary bodies should be much smaller than those asteroidal counterparts, regardless of comets' nuclear sizes, which hints a way to differentiate cometary candidates from asteroids using thermal inertia information. We thus selected two comet-like objects from AKARI satellite of JAXA, namely, 107P/ (4015) Wilson-Harrington and P/2006 HR30 (Siding Spring), and applied simple thermophysical model to test the idea. Both targets did not show any comet-like activity during the observations. From the model, we found Wilson-Harrington to have size of 3.7-4.4 km, geometric albedo 0.040-0.055 and thermal inertia of 100-250 J m-2 K-1 s-0.5, which coincide with previous works, and HR30 to have size of 24-27 km, geomoetric albedo of 0.035-0.045 with thermal inertia of 250-1000 J m-2 K-1 s-0.5. HR30 is found to have the rotation pole near the ecliptic plane (the latitude between -20 and +60 deg). Based on the results, we conjecture that comet-like objects are not clearly distinguishable from asteroidal counterpart using thermal inertia.

• 한국대기환경학회지
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• 제10권4호
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• pp.233-244
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• 1994

The phenomenon of yellow sand (dust clouds) occurred in Korea during the spring of 1993 and 1994 is studied in detail. In total 6 cases including 15 days of yellow sand were observed in 1993 and the annual number of these events was found to increased. Examinations in this study include meteorological charts satellite imagery, pilot reports (PIREP) of Korea Air Force, and air concentrations of total suspended particulates(TSP). We present on estimation of total atmospheric loadings based on the observation and theory. According to the PIREP, in general the dust clouds travelled in the lower troposphere up to the level 5km. The visibility within the clouds was in the range of 3-8km The area covered by yellow sand in an event exceeded 0.4 M $\textrm{km}^2$ . According to trajectory analyses, dust clouds invaded Korea in April and May 1993 were landed in the sink area after 2~4 days travelling for 2,000~3,000km from a source region. Estimates of total atmospheric loadings of a dust cloud for April 23~24 in 1993 were 1.5 M ton. In addition, 7 dust storms were also reported in synoptic observations in NW China and Mongolia during the spring in 1994. The yellow sand was not reported with meteorological observations in Korea, however pilots reported significant dust clouds over the Yellow Sea on 8 and 13 April and 20 May 1994.