• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.423-434
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• 2016

Surface emissivity and its background values according to each sensor are mandatorily necessary for Mid-Wavelength Infrared (MWIR) remote sensing to retrieve surface temperature and temporal variation. This study presents the methods and results of Land Surface Emissivity (LSE) of the MWIR according to land cover over the Korean Peninsula. The MWIR emissivity was estimated by applying the Temperature Independent Spectral Indices (TISI) method to the Visible Infrared Imaging Radiometer Suite (VIIRS) band 4 Day/Night images ($3.74{\mu}m$ in center wavelength). The obtained values were classified according to land-cover types, and the obtained emissivity was then compared with those calculated from a standard Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) spectral library. The annual means of MWIR emissivity of Deciduous Broadleaf Forest (0.958) and Mixed Forest (0.935) are higher than those of Croplands (0.925) and Natural Vegetation Mosaics (0.935) by about 2-3%. The annual mean of Urban area is the lowest (0.914) with an annual variation of about 2% which is by larger than those (1%) of other land-covers. The TISI and VIIRS based emissivity is slightly lower than the ASTER spectral library by about 2-3% supposedly due to various reasons such as lack of land cover homogeneity. The results will be used to understand the MWIR emissivity properties of the Korean Peninsula and to examine the seasonal and other environmental changes using MWIR images.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.97.2-97.2
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• 2013

달 및 행성탐사선에 탑재된 적외선 분광기는 태양계 행성들의 지표 및 대기 성분 관측을 위해 널리 활용되고 있다. 적외선 분광기 관측 영역 중 $3-5{\mu}m$ 파장 대에서는 행성의 지표 및 대기에 존재하는 물(얼음), 이산화탄소, 일산화탄소, 메탄, 중수와 같은 여러 성분의 분광선 관측이 가능하다. 이 파장대를 관측한 해외 탐사선 탑재체 사례로는 화성의 경우 Mars Express에 탑재된 OMEGA와 PFS, 소행성의 경우 ROSETTA에 탑재된 VIRTIS 등이 해당된다. $3-5{\mu}m$ 파장대의 분광기는 국내에서 개발 사례가 없으며 해외에서도 달 탐사선에 탑재된 바가 없어 달 얼음과 관련된 다른 파장대의 자료와 상호보완이 가능한 자료를 제공할 것으로 기대된다. 본 연구에서는 달 및 행성탐사를 위한 $3-5{\mu}m$ 파장 영역을 탐사하는 적외선 분광기의 요구사양을 그 과학임무에 비추어 제안하고자 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.28-35
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• 2021

Infrared (IR) stealth technology to protect aircraft from heat-tracking missiles is a very important factor in the development of military aircraft. In this study, the intensities of signal generation were compared by observing the IR signals generated from the plumes of the engine and identifying them for each measurement angle. To simulate a jet engine applied to an actual aircraft, a small turbojet engine was constructed, the infrared signal characteristics for each wavelength were identified according to the measurement angle, and the total infrared radiance was derived by integrating the signal for each wavelength. Through this study, we intend to present basic data for improving the infrared stealth performance of aircraft.

• Textile Coloration and Finishing
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• v.8 no.2
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• pp.71-77
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• 1996

최근 원적외선에 대한 붐이 일고 있다. 그 원인은 다양하게 생각할 수 있지만 주요한 원인은 무엇보다도 불황을 타개하려는 기업의 신규사업이다. 특히 섬유 업계에 있어서는 종래의 제품만으로는 발전이 없고, 그 존속마저도 위태로운 상황이다. 이와 같은 배경 아래 섬유 관련 업계에서는 새로운 기능을 부여한 상품의 개발에 여념이 없다. 이들 기능성 섬유의 하나가 원적외선 섬유이다. 원적외선은 1800년 독일 과학자 하셀이 태양광을 스펙트럼으로 나누는 연구 중 눈에 보이는 파장중 적색의 외측에서도 한온계에 감지되는 열선이 있는 것을 발견했다. 그 열선은 눈에는 보이지 않지만 적색광보다는 한온계의 온도 상승이 큰 것을 알았다. 적색광 외측에 있는 열선으로 다른 사람들은 이것을 적외선이라 불렀지만 맥스웰에 의해서 적색광도 적외선과 같은 전자파로서 이론 체계를 붙이게 되었다.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.30-37
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• 2015

The design and implementation of a radiative temperature measurement system for a flash light are carried out. Since a massive amount of energy is emitted within a very short time, it is impossible to measure the temperature of a flash with a conventional method. It is also irrelevant to measure one with an optical noncontact method. In this paper, a radiative temperature measurement system using the ratio of spectral radiances over mid- and long-wavelength infrared (IR) is designed and implemented. The implemented system utilizes optical bandpass filters to divide the wavelengths within the mid- and long-wavelength IR ranges, and pyroelectric IR detectors to measure the incident optical power of each wavelength-divided channel. It is shown that the measured radiative temperature of a flash is in the range of 1393 to 1455 K. This temperature-measurement system can be utilized to obtain information about the spectral radiance of a flash as a light source, which is of crucial importance to approaching the modeling and simulation of the various effects of a flash.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.149.1-149.1
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• 2011

보현산 천문대의 근적외선 카메라시스템인 KASINICS(KASI Near Infrared Camera System)를 사용하여 다주기 변광성 BL Cam을 관측하였다. BL Cam(${\alpha}=03^h47^m19^s$, ${\delta}=+63^{\circ}22'7"$[J2000.0], V=13.10, ${\Delta}V$=0.33mag)은 광학적 쌍성으로 SX Pheoenics 변광성 중 하나이며 0.03 - 0.08day의 짧은 주기를 갖는 다주기 변광성으로 알려져 있다. 대상 천체의 적외선 관측을 위하여 한국천문연구원에서 개발한 지상 망원경용 근적외선 카메라 시스템 KASINICS를 사용해 J, H, Ks filter로 시계열 관측을 하였다. 대상 천체의 가시광 파장대에서의 관측 자료와 적외선 파장대에서의 관측 자료를 비교 분석함으로써 천체의 외곽층에서 발생하는 상호작용에 대해 알아볼 수 있다.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.31.2-31.2
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• 2011

The Vista Variable in the Via Lactea(VVV)는 European Southern Observatory(ESO) Public Survey 중 하나로 Near-IR에서 (주로 K-band)에서 관측되며 1929시간에 걸쳐 은하 중심부의 더 깊은 영역에 대한 관측을 수행할 것이다. VVV Survey를 통해 520 sq. deg에 걸친 영역에서 33개의 잘 알려진 구상성단과 350개의 산개성단을 포함한 ~109개의 별에 대한 광도 곡선을 얻을 수 있을 것으로 예상되며 이들을 분류하기 위해 자동화된 분류 체계가 필요할 것이다. 본 연구는 VVV Survey의 일환으로 보현산 천문대의 근적외선 카메라시스템 KASINICS를 이용하여 Cataclysmic Variable stars에 대한 관측을 시행하고 있다. Cataclysmic Variable stars는 초신성 폭발이나 쌍성계 중 한 쪽 별에서 다른 쪽 별로 대기가 유입되었는 경우 등에 의해 광도가 급격히 증가하는 천체로 아직 많이 연구되지 않은 적외선 파장대로 관측함으로써 적외선영역에서의 물리적 특성에 대한 분석을 하고자 한다. 본 발표에서는 보현산 천문대의 근적외선카메라시스템 KASINICS에서 관측한 결과의 일부를 소개하고자 한다.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.2
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• pp.51-59
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• 2008

While the infrared imaging satellites with the several type were developed and operated in the foreign countries, we do not have the domestic infrared imaging satellite up to now. In the paper, the general characteristics of infrared and the applications of infrared image were introduced. Also the oversea development status of the infrared imaging satellite was surveyed and introduced to this paper. According to foreign status, the infrared image is utilized in various application including the forest fire monitoring, the volcano activity research, sea surface temperature measurement, land surface temperature calculation, the climate change research, and the environment monitoring. According to these trend the development of the domestic infrared imaging satellite in low earth orbit was required.

• Korean Journal of Optics and Photonics
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• v.19 no.3
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• pp.229-236
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• 2008

The optimum conditions of second harmonic generation (SHG) can be successfully achieved experimentally using single pass and double pass methods of a pumping beam. The beam has a power of several Watts radiated by a DOFA (Diode Laser Oscillator & Fiber Amplifier) system, which is a high power CW wavelength tunable infrared laser system, in a PPLN (Periodically Poled MgO doped Lithium Niobate) nonlinear crystal. In the case of a single pass method, the parameters are the wavelength of 535 nm for SHG and the output power of 245 mW generated from the pumping input beam with wavelength of 1070 nm and the power of 2.45 W at phase matching temperature of $108.9^{\circ}C$. The conversion efficiency of SHG was 10%. In order to enhance the output of SHG, the double pass method of the SHG system of a PPLN using a concave mirror for the retroreflection and a pair of wedged flat windows for phase compensation was also presented. In this double pass system, we obtained the SHG output beam with the wavelength of 535 nm and the maximum power of 383 mW at optimum phase matching temperature of $108.5^{\circ}C$ by using an incident pumping beam with wavelength of 1070 nm and the power of 2.45 W. The maximum conversion efficiency is 15.6%, which is more than that of the single pass method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.44-51
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• 2019

Three types of samples with defects were measured by lock-in med-IR (infrared) thermography with various lock-in frequencies for different materials. The lock-in method can be used to detect defects when an external energy source is applied to the object, the non-uniformity of the incident thermal energy distribution is eliminated, and the camera's measurement cycle is synchronized with the load cycle of the incident energy source. For inspecting samples with defects, results of thermal images are analyzed when three types of materials, i.e., SM45C, STS316L, and AL6061 are tested and three lock-in frequencies, i.e., 0.08, 0.1, and 0.12 Hz are applied. In this study, the optimal lock-in frequencies were determined by comparing the results of each material and lock-in frequency measured using the mid-IR camera.