• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.382-388
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• 2022

Satellite communication for high altitude platform stations (HAPS) and low earth orbit (LEO) systems suffer from dust and sand (DU&SA) storms in the desert regions such as Saudi Arabia. These attenuations have a distorting effect on signal fidelity at high frequency of operations. This results signal to noise ratio (SNR) to dramatically decreasing and leads to wireless transmission error. The main focus in this paper is to propose common relations between HAPS and LEO for the atmospheric impairments affecting the satellite communication networks operating above Ku-band crossing the propagation path. A double phase three dimensional relationship for HAPS and LEO systems is then presented. The comparison model present the analysis of atmospheric attenuation with specific focus on sand and dust based on particular size, visibility, adding gaseous effects for different frequency, and propagation angle to provide system operations with a predicted vision of satellite parameters' values. Skillful decision and control system (SD&CS) is proposed to control applied parameters that lead to improve satellite network performance and to get the ultimate receiving wireless signal under bad weather condition.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.142-145
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• 2007

In order to analyze hyper-spectral properties of Sand and Dust Storm (SDS), dust observation experiment has been performed at the Korea Global Atmosphere Watch Center (KGAW) in Anmyeon form early March to middle of May, 2007. We measured down-welling radiances by using ground-based Fourier Transform Infrared Spectroscopy (FT-IR) at the time of overpass of AIRS. And radiative transfer model simulation has been carried out to estimate the effects of size distribution, components, and altitude of SDS over the high resolution infrared spectrum in the range of 500-1500 $cm^{-1}$ with a line-by-line radiative transfer model and compared them with FT-IR and AIRS/Aqua observing data.

• 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.

• 환경영향평가
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• 제13권6호
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• pp.277-284
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• 2004

The chemical composition and properties of soil were determined at selected sites, such as Loess plateau, Gobi and sand deserts in northern China, where most dust storms occur. Although the transport of this sort of dust storms to Korean peninsula is a well-documented phenomenon, there is not enough information about the very source regions. In this reason, this study tried to measure the chemical composition, including soil elements, anthropogenic elements and ions for soil samples so that certain properties of some major source regions of Asian Dust can be provided. Furthermore, the results are classified into four types of soil like Loess, Loess & sand, Gobi, and sand in order to identify the characteristics and difference among the types. $(X/Al)_{crust}$ values for each soil type were also calculated in this study and compared with those of other references including Asian Dust material(ADM). The results indicated that Ca contribution was higher than Al in all the soil types of this study including ADM and, compared with the values of urban area, contribution of anthropogenic elements such as Cr, Pb, Zn was quite low. However, it must be noted that there is such a variation in the result of soil composition, but it is also certain that the very source region soil composition resolved from this study could support the enhanced study on Asian Dust phenomenon in Korea.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.93-100
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• 2021

Satellite communication for high altitude platform stations (HAPS) and geostationary orbit (GEO) systems suffers from sand and dust (SANDU) storms in desert and arid regions. The focus of this paper is to propose common relations between HAPS and GEO for the atmospheric impairments affecting the satellite communication networks operating above Ku-band crossing the propagation path. A double phase three-dimensional relationship for HAPS and GEO systems is then presented. The comparison model present the analysis of atmospheric attenuation with specific focus on sand and dust based on particular size, visibility, adding gas effects for different frequency, and propagation angle to provide systems' operations with a predicted vision of satellite parameters' values. Thus, the proposed system provides wide range of selecting applicable parameters, under different weather conditions, in order to achieve better SNR for satellite communication.

• 한국대기환경학회지
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• 제7권3호
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• pp.197-202
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• 1991

It is observed that the outbreak of dust storms (yellow sand) from Northern China and Mongolia occurs a few times in April 1988 and 1990. It is found that a dust storm initiated with strong gusty winds after the passage of a cold front, particularly after defrost of the ground surface of a source region in the early spring. According to meteorological chart, satellite images and trajectory analyses, dust clouds invaded Korea in April 1988 and 1990 were landing in the sink area after 2 $\sim$ 4 days travelling for 2,000 $\sim$ 3,000 km from a source region. It was also observed that in the west coast total suspended particulated (TSP) were 100 $\sim$ 200 $\mug m^{-3}$ and sulphates $(SO_4=)$ were 3 $\sim$ 10 $\mug m^{-3}$. These values clearly exceed the concentrations of a background level measured in the Arctic and Atlantic Ocean. Trajectory analyses and meteorological analyses suggest that the high values occurred with prevailing westerly flows coming from anthropogenic sources in China. High concentrations of air pollutants occurred in the backside of an anticyclone and in the area "col".col".uot;.

• 한국전기전자재료학회논문지
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• 제27권6호
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• pp.343-349
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• 2014

It is summarized that potential causes of performance degradations and failure mechanisms of crystalline silicon photovoltaic (PV) modules installed in Middle East area. In addition, we also reviewed current PV module qualification test (IEC 61215) and the methods for detection of wear-out fault. The failure of PV modules in the extreme environmental conditions such as deserts is mainly due to high temperature, humidity, and dust storms. In particular, cementation phenomenon caused by combination of sand and moisture leads to rapid degradation in the performance of PV modules. In order to evaluate and guarantee the long term reliability of PV modules, specific qualification tests such as sand dust test, salt mist test and potential induce degradation test considering operating environment of PV module should be carried out.

• 한국환경과학회지
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• 제11권2호
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• pp.111-120
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• 2002

Asian dust(or yellow sand) occurs mainly in spring and occasionally in winter in east Asia, when the weather conditions are under an upper trough/cut-off low and surface high/low pressure system during blocking episode days associated with the stationary patterns of the upper level jet stream. The transport mechanism for Asian dust during the blocking episode days in spring 2001 was analyzed using the TOMS aerosol index and meteorological mesoscale model 5(MM5). Based on the E vector, an extension of an Eliassen-Palm flux, the blocking episode days were found to be associated with the development of an upper cut-off low and surface cyclones. Concurrently, the occurrence of dust storms was also determined by strong cold advection at the rear of a jet streak, which exhibited a maximum wind speed within the upper jet stream. As such, the transport mechanism for Asian dust from China was due to advection of the isentropic potential vorticity(IPV) and isentropic surfaces associated with tropopause folding. The transport heights for Asian dust during the blocking episode days were found to be associated with the distribution of the isentropes below the IPV At the same time, lee waves propagated by topography affected the downward motion and blocking of Asian dust in China. The Asian dust transported from the dust source regions was deposited by fallout and rain-out with a reinforcing frontogenesis within a surface cyclone, as determined from satellite images using TOMS and GMS5. Accordingly, these results emphasize the importance of forecasting jet streaks, the IPV, and isentropes with geopotential heights in east Asia.

• 한국지구과학회지
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• 제24권4호
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• pp.315-324
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• 2003

서울시에서 설치하여 운영중인 대기질 측정소의 입자상물질을 대표하는 PM$_{2.5}$, PM$_{10}$, TSP와 황사기간 중 고용량고기포집기로 채취한 먼지성분을 분석, 평가하였다. 1990년도부터 2002년 11월까지 서울에서 관측된 황사일수는 2000년 이후 발생빈도가 증가하였으며 황사지속시간도 길어지는 경향을 보였다. PM$_{10}$/TSP 비율은 황사시 2000년, 2001년도에 각각 52.9%, 59.4%로 비황사시에 비해 PM$_{10}$의 비율이 약 10% 정도 낮은 것으로 미루어 황사시 10 ${\mu}$m이상의 입경이 큰 입자 영향이 컸던 반면에 2002년 황사시에는 PM$_{10}$의 영향이 오히려 크게 나타나 PM$_{10}$이 TSP 중의 71.4%에 달하였다. 황사가 전체 먼지농도에 미치는 기여율은 2002년도에 PM$_{2.5}$ 11.9%, PM$_{10}$ 23.1%, TSP 19%로 가장 높은 기여도를 보여 황사가 전체 면지농도에 미치는 영향이 매우 크다는 것을 알 수 있었다.

• 한국수자원학회논문집
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• 제37권11호
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• pp.959-967
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• 2004

충북 청주시에 위치한 충북대학교에서 강수에 따른 습성강하물 중의 TN, TP 및 COD의 농도와 오염부하를 조사하였다 강수사상에 대한 샘플은 1998년에서 2003년까지 채집되었다. 오염물질의 강수량가중평균 농도는 TN이 0.60mg/L, TP가 0.014mg/L, COD는 4.8mg/L이었는데, 이는 각각의 산술평균보다 26, 18, 14% 작게 나타났다. TN, TP 및 COD의 농도는 강수량이 증가함에 따라 감소하는 경향을 나타냈다. 모든 수질항목은 됨에 가장 많이 나타났는데, 이는 풍식 및 황사에 의한 먼지, 꽃가루 등 때문으로 생각된다. 습성강하물의 평균 연간부하는 TN 7.9kg/ha$\cdot$yr, TP 0.19kg/ha$\cdot$yr, COD 53.9ka/ha$\cdot$yr로 나타났는데, 이를 일본에서 보고된 각각의 연간부하와 비교하면 TN과 TP는 비슷했으나, COD는 약간 놀게 나타났다.