• 설비공학논문집
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• 제4권4호
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• pp.316-322
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• 1992

A simplified TAC method was developed for the selection of solar atmospheric transmittance data fundamental to the calculation of design solar radiation for the peak cooling load calculation using ETD method. The summer and autumn solar atmospheric transmittance data of the 11 major cities in Korea were obtained. Based on the simplified TAC method, the atmospheric transmittance data were selected by the TAC 2.5% of July instead of the TAC 2.5% of June through September for summer and the TAC 5.0% of October instead of the TAC 2.5% of October and November for autumn. Results show that the atmospheric transmittance data at solar noon were in the range of 0.61-0.66 for summer and 0.78-0.82 for autumn except for Pusan and Incheon.

• 한국군사과학기술학회지
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• 제9권4호
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• pp.97-103
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• 2006

A synthetic infrared image can be effectively utilized in various fields such as the recognition and tracking of targets as long as its quality is good enough to reflect the real situations. One way to improve its quality is to use the reference atmosphere which best describes atmospheric properties of regional areas. The east asian reference atmosphere has been developed to represent atmospheric properties of the east asia including Korean peninsula. However, few research has been conducted to examine the effects of this east asian reference atmosphere on the modeling and simulation. In this regard, this paper analyzes the effects of the east asian reference atmosphere on a synthetic infrared image. The research compares the atmospheric transmittance, the surface temperature, and the radiance obtained by using the east asian reference atmosphere with those of the midlatitude reference atmosphere which has been widely applied in the east asia. The results show that the differences of the atmospheric transmittance, the surface temperature, and the radiance between the east asian reference atmosphere and the midlatitude reference atmosphere are significant especially during the daytime. Therefore, it is recommended to apply the east asian reference atmosphere for generating a synthetic infrared image with targets in the east asia.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.49-56
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• 2005

A long-path transmissometer is one of the optical instruments widely used to measure atmospheric light extinction coefficient without enclosing a light beam and perturbing aerosols. Over the past two decades, a number of measurements have been carried out using the long-path transmissometer manufactured by OPTEC, Inc. Calibration of the transmissometer should be performed when any component of the transmissometer system is interchanged or installation condition is changed. For a better calibration of the transmissometer, application of a modified calibration method for the existing neutral density (ND)-filter method was recommended for the computation of the atmospheric transmittance using model MODTRAN 4 in this study. It was revealed that the measured light extinction coefficient from the transmissometer which was calibrated using the existing ND-filter method could be overestimated due to the assumption of the atmospheric transmittance suggested by OPTEC, Inc. The uncertainty of the measured light extinction coefficient from the transmissometer calibrated based on the modified ND-filter method was calculated to be approximately $13Mm^{-1}$.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.190-198
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• 2010

A set of radiative transfer software named CART (Combined Atmospheric Radiative Transfer) has been developed to rapidly calculate atmospheric transmittance and background radiance. The spectral resolution of CART is $1cm^{-1}$, and the spectral region covers from 1 to $25000cm^{-1}$. CART has five characteristic features, and it can be applied to many fields. The features and applications of CART are summarized in detail.

• 대한설비공학회지:설비저널
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• 제16권4호
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• pp.375-382
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• 1987

Accurate solar radiation data are fundamental to the design of HVAC systems and solar driven devices. Unfortunately, the total radiation data on a horizontal surface has been only reported by meteorological office. Consequently, there is interest in development of model to estimate the solar radiation data. Based on the statistically estimated TAC data which were obtained from measured hourly values collected over a period of ten years at Seoul, the solar radiation model was determined. Atmospheric transmittance for this model was presented in the form of polynominal.

• 한국전산유체공학회지
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• 제22권1호
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• pp.88-94
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• 2017

The IR signal entering into a sensor is composed of the following components: the self-emitted component directly from the object surface, the reflected components of the solar and sky irradiance at the object surface, and the scattered component by the atmosphere without reference to any object surfaces. The self-emitted and reflected components from the object can be lowered by the atmospheric layer between the object and the IR sensor. The principle factors influencing the atmospheric transmittance are the air temperature, the relative humidity and the observation distance. Previous studies on IR signal transmission through the atmosphere are focused on uniform atmospheric conditions and the non-uniform nature of the atmosphere was not properly treated in modeling. In this study, we use the local atmospheric transmittance to simulate the non-uniform atmosphere in analyzing the IR signal from the object surface. The results show that the nonuniform analysis of the atmosphere becomes more important as the wavelength of IR signal increases.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.310-313
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• 2007

In this study, a new technique for atmospheric transmittance estimated from ALOS PRISM data is developed. It is based on satellite's observing radiances of different view angles and assumes that the cause of difference in radiances is the different view angles. The ALOS PRISM has three independent optical systems for viewing forward and backward and producing a stereoscopic image along the satellite's track. This stereo pair data can be used to estimate the transmittance according to the radiative transfer theory. This derived transmittance will be validated by the AERONET data and compared with the MODTRAN4 simulation results. Results show that the higher the land cover albedo, the better the derived transmittance compared to the AERONET data. Besides, this technique also shows the transmittance retrieval will be underestimated for the low land cover albedo.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.191-195
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• 2012

Among the atmospheric effect of laser propagation, the variations of the radiation transmittance by water aerosol evaporation have quantitatively been investigated. When the aerosol was exposed by a 1.07 ${\mu}m$ cw fiber laser, the increased amount of the transmittance variation was a maximum of 19.1% and the volume concentration variation of aerosol was observed as an increasing of laser intensity. Also, significant irregularity of refractive index was not found in the heated area during the continuous laser heating.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.119-138
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• 1998

최근에 인공위성에 의한 대기 중의 미량 기체 관측이 활발하다. 따라서 이들 자료의 처리기법 개발이 매우 중요하다. 그러므로 이 연구에서는 인공위성에 의해 태양 엄폐범(太陽 掩蔽法: Solar Occultation Method)으로 관측한 대기 주연 경로(周緣 經路: limb path)의 접선 고도별 평균 투과율로부터 연직 오존 분포를 도출하고, 온도와 기압 오차의 민감도 오차의 민감도 실험을 하고자 한다. 여기에서 서울의 반전(Umkehr)관측에 의하여 구한 연평균 연직 오존분포로 계산된 평균 투과율을 인공위성으로부터 관측된 평균 투과율로 가정하였다. HALOE SIDS (Hallogen Occultation Experiment Simulated Instrument Data Set)의 연직 오존 자료를 초기치로 하고 온도와 기압의 연직 분포를 입력값으로 하여 대기 평균 투과율을 파장 $9.89{\mu}m$와 $10.02{\mu}m$ 사이에서 접선고도별로 계산했다. 관측 평균 투과율에 대하여 계산한 평균 투과율로부터 오존 분포 법으로 접선고도 10km에서 50km까지 매 3km마다 오존 농도를 도출하였다. 도출된 서울의 연직 오존 분포를 관측한 연직 오존 분포와 비교하였다. 이 결과에 의하면 전 고도에 걸쳐서 서울의 연직 오존 분포가 오차가 거의 없을 정도로 정확하게 도출되었다. 그리고 민감도 실험을 위하여 관측 평균 투과율에$\pm0.001$, 각 층의 온도에 $\pm3K$, 그리고 각 층에 기압의 $\pm3\%$의 강제 오차를 각각 주었다. 이들 각 오차는 ADEOS/ILAS 관측 오차에 근거하였다. 이들의 결과는 투과율 오차에 대하여 -6.5%에서 +6.9%, 온도 오차에 대하여 -9.5%에서 +10.5, 그리고 기압 오차에 대하여 -5.1%에서 +5.4%의 고도별 오존 량 오차가 각각 나타났다. 태양 엄폐 법에 의해 비교적 정확한 연직 오존 분포를 도출할 수 있었다. 이 도출 과정에서 특히 온도 관측이 중요함을 알 수 있었다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 춘계학술대회 논문집
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• pp.293-294
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• 2006