• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.174-180
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• 2010

Conductive and radiative thermal model configurations of an imager of a geostationary satellite are presented. A two-plane method is introduced for three dimensional conductive coupling which is not able to be treated by thin shell plate thermal modeling technique. Especially the two-plane method is applied to massive matters and PIP(Payload Interface Plate) in the imager model. Some massive matters in the thermal model are modified by adequate correction factors or equivalent thickness in order to obtain the numerical results of thermal modeling to be consistent with the analytic model. More detailed nodal breakdown is specially employed to the object which has the rapid temperature gradient expected by a rule of thumb. This detailed thermal model of the imager is supposed to be used for detailed analyses and test predictions, and be correlated with the thermal vacuum test results before final in-flight predictions.

• 한국군사과학기술학회지
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• 제19권6호
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• pp.698-702
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• 2016

Thermal imager is now regarded as one of the key observation devices for ISR activities and getting important more and more. As other detectors, however, the thermal detectors also have maximum input and therefore they will be saturated if the input IR energy exceeds the allowed range. The saturation in the thermal detector makes it impossible to distinguish the target from background, as a result, the thermal imager does not perform its own mission anymore. In order to get an insight related with the image saturation, this paper develops a saturation model for a thermal imaging system, not a thermal detector. The proposed modeling starts from analyzing the specification of a thermal imager. Coupled with the characteristic parameters of the object, the saturation model can be used to predict the distance on which the detector is saturated. The proposed saturation model prove its validity by applying it for the case of observing a flash-bang.

• 한국전산유체공학회지
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• 제15권2호
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• pp.28-34
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• 2010

Conductive and radiative thermal model configurations of an imager of a geostationary satellite are presented. A two-plane method is introduced for three dimensional conductive coupling which is not able to be treated by thin shell plate thermal modeling technique. Especially the two-plane method is applied to massive matters and PIP(Payload Interface Plate) in the imager model. Some massive matters in the thermal model are modified by adequate correction factors or equivalent thickness in order to obtain the numerical results of thermal modeling to be consistent with the analytic model. More detailed nodal breakdown is specially employed to the object which has the rapid temperature gradient expected by a rule of thumb. This detailed thermal model of the imager is supposed to be used for analyses and test predictions, and be correlated with the thermal vacuum test results before final in-flight predictions.

• 전자공학회논문지B
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• 제31B권1호
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• pp.49-56
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• 1994

This paper describes the design principles and methods of electronic processor for thermal imager with the SPRITE detector, operating in the 8-12 micron band. The thermal imager consists of a optical scanner containing the detector and an electrical signal processor. The optical scanner utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using 5 elements of the detector. And the electronic processor has pre-processing of 5 chnanel's thermal signal from the detector, and performs digital scan conversion to reform the parallel data stream into serial analog data compatible with conventional RS-170 video. Through the designed electronic processor, we have acquired a satisfactory thermal image. And the MRTD (Minimum Resolvable Temperature Difference) is 0.5$^{\circ}$K at 7.5 cycles/mm.

• 한국군사과학기술학회지
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• 제9권2호
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• pp.111-117
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• 2006

This paper describes the design principles and methods of electronic processor for thermal imager with 320$\times$240 staring array infrared detector. For the detector's nonuniformity correction and excellent image quality, we have designed the multi-point correction method using the defocusing technique of the optics. And to enhance the image of low contrast and improve the detection capability, the new technique of histogram processing has been designed. Through these image processing techniques, we have developed the high quality thermal imager and acquired a satisfactory thermal image. The result of MRTD(Minimum Resolvable Temperature Difference) is $0.1^{\circ}C$ at 4cycles/mard.

• 한국항공우주학회지
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• 제47권4호
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• pp.309-318
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• 2019

한국형 달 궤도선(Korea Pathfinder Lunar Orbiter, KPLO)에 탑재되는 달 표면지형 광학관측기(Lunar Terrian Imager, LUTI)의 열설계를 수행하고, 열해석을 통하여 열설계의 건전성을 검증하였다. 달 임무궤도의 열환경은 지구궤도와 달리 달 표면의 IR 복사가 중요하므로 이를 열설계에 반영하여야 한다. 위성 외부에 노출되는 부품이나 모듈은 가능한 MLI로 단열시키지만 경통이나 방열판은 기능상 노출되므로 복사형상계수의 개념을 이용한 thermal shield를 전면에 장착함으로써 IR 복사를 완화시킨다. 태양복사를 거의 받지 않는 방열판의 전면부는 IR 방사율이 중요하며, 경통과 같이 열변형에 취약한 부품은 복사히터를 사용하여 온도구배를 최소화시킨다. 열해석 결과분석을 통하여 LUTI의 열설계는 다양한 상황에서 안정적임을 확인하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.891-894
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• 2002

We studied characteristics of polyimide (PI) about Liquid Crystal on Silicon (LCOS) microdisplay. In order to compare two kinds of PI and choose one PI, we measured some items. First, we measured thermal imidization of SE-7492, SE-5291 (Nissan) PI using FT-IR. The results of thermal imidization are same 85%for SE-7492 and 86% for SE-5291. The second, we measured voltage-holding ratio (VHR) of LCOS imager using two kinds PI and one liquid crystal (LC) that is a mixture developed by Merck. The third, we measured contrast ratio (C/R) of LCOS imager using function generator from ov to 4V. The results of VHR and C/R are higher LCOS imager using SE-7492 than LCOS imager using SE-5291. And last we measured response time and the result is same two types LCOS Imagers. So, we choose PI of LCOS imager and concluded that LC is much better matched of PI using SE-7492.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.135-141
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• 2009

A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. According to the results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature is found slightly out its specification, therefore further detailed analyses should be continued on this element.

• 한국전산유체공학회지
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• 제15권1호
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• pp.24-30
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• 2010

A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. The results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature and shutter wheel motor gradient are found slightly out their specification, therefore further detailed analyses should be continued on these elements.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2010년도 춘계학술대회 논문집
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• pp.693-694
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• 2010