• Title/Summary/Keyword: Optical instruments

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Development Trend of Japanese Optical Payloads (일본의 광학탑재체(지상/해양 관측용) 개발 경향)

  • Myung, Hwan-Chun
    • Current Industrial and Technological Trends in Aerospace
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    • v.8 no.2
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    • pp.65-75
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    • 2010
  • In 2014, Japan is scheduled to launch GCOM(Global Change Observation Mission)-C for the global change observation mission, where SGLI(Second-generation Global Imager) is planned for optical multi-channel observation ofa radiation budget and a carbon cycle. Depending on the spectral channels, SGLI consists ofS GLI-VNR(Visible Near IR) and SGLI-IRS(IR Scanning). Their main design schemes are mostly based upon those ofthe previous instruments ever developed in Japan, which is intended to reduce the development risk for the advanced performance. Accordingly, for the better understanding ofSG LI, the paper reviews the history oft he Japanese optical payloads from two different views: VNR and IR. Through the review, a comparison among the Japanese optical instruments is made to distinguish the development trend toward SGLI ofGC OM-C.

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THE SOLAR-B MISSION

  • ICHIMOTO KIYOSHI;TEAM THE SOLAR-B
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.307-310
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    • 2005
  • The Solar-B is the third Japanese spacecraft dedicated for solar physics to be launched in summer of 2006. The spacecraft carries a coordinated set of optical, EUV and X-ray instruments that will allow a systematic study of the interaction between the Sun's magnetic field and its high temperature, ionized atmosphere. The Solar Optical Telescope (SOT) consists of a 50cm aperture diffraction limited Gregorian telescope and a focal plane package, and provides quantitative measurements of full vector magnetic fields at the photosphere with spatial resolution of 0.2-0.3 arcsec in a condition free from terrestrial atmospheric seeing. The X-ray telescope (XRT) images the high temperature (0.5 to 10 MK) corona with improved spatial resolution of approximately 1 arcsec. The Extreme Ultraviolet Imaging Spectrometer (EIS) aims to determine velocity fields and other plasma parameters in the corona and the transition region. The Solar-B telescopes, as a whole, will enable us to explore the origins of the outer solar atmosphere, the corona, and the coupling between the fine magnetic structure at the photosphere and the dynamic processes occurring in the corona. The mission instruments (SOT/EIS/XRT) are joint effort of Japan (JAXA/NAO), the United States (NASA), and the United Kingdom (PPARC). An overview of the spacecraft and its mission instruments are presented.

Study on the IR Measurement Scheme and Requirement for Its Evaluation from a Naval ship Considering the Meteorological Conditions (기상 조건에 따른 함정의 적외선 방사신호 성능 평가시 고려요소 및 계측 방안 연구)

  • Gil, Tae-Jun;Cho, Yong-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.4
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    • pp.459-465
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    • 2007
  • This paper deals with the development of measuring methodology and the requirement for its evaluation of the infrared radiation from a naval ship to optical sensors, considering the Meteorological conditions. Factors required for measuring the apparent temperature and infrared radiation are identified and two methods are suggested based on the measuring instruments carried by ship or aircraft. and target operation in the Meteorological conditions is considered. This study describes some factors affecting the IR signature. required instruments to obtain the IR signal considering the naval ship.

Air Pollution Measurement and Analysis using a Differential Optical Absorption Spectroscopy (Differential Optical Absorption Spectroscopy를 이용한 대기오염 측정 및 분석)

  • 김상우;원재광;박기학;윤순창;홍천상
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.5
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    • pp.375-384
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    • 2001
  • Optical remote sensing techniques are particularly advantageous over the conventional fixed point methods because with these methods large-area monitoring can be possible and sample preparation difficulties are avoidable. Instruments based on the differential optical absorption spectroscopy (DOAS) technique are widely used for monitoring air pollutants in urban areas in recent years. In this study, $O_3$, SO$_2$, NO$_2$, and VOCs (benzene, toluene, xylene, and styrene) are measured continuously at Sihwa industrial area using a DOAS from February to November. 1999. Intercomparison between the DOAS method and the conventional methods (filed point samplers for $O_3$, NO$_2$, and SO$_2$, and adsorbent sampling methods and gas chromatography for VOCs) are performed simultaneously at the same site. The time series of the DOAS data and that of fixed point method show good match at the view point of the tendency, but the absolute concentration values of these two methods differ quite a lot from each other; correlation coefficients shows 0.78 for $O_3$and 0.97 for SO$_2$. However, the results of VOCs measurements are not quite satisfactory ; the spectral interference with $O_2$and $O_3$appears to be the major cause of the errors for VOCs .

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The Principle of Moving Image and the Development of the Optical Instruments in the 19th Century - On the Theory of Afterimage Effect and the Scientific Development of Moving Image - (동영상의 원리와 19세기 시각기구의 발전과정 - 잔상이론과 동영상의 과학적 발전에 대해 -)

  • LEE, Sang-Myon
    • Korean Association for Visual Culture
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    • v.19
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    • pp.189-221
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    • 2012
  • This thesis investigates the development of optical instruments in the 19th century, before the birth of the cinema, and the principle of the perception of moving images. For this purpose it traces the development stages of the optical instruments which demonstrated 'illusion of movement' from 1820s when the 'persistence of vision' had begun to be researched by scientists. Then, it examines the theory of the 'persistence of vision' or 'afterimage effect' known as the principle in the perception of illusion of movement produced from moving images. The optical instruments in the 19th century that presented the illusion of movement began with the Thaumatrope (double-sided picture disc), and appeared from the Phenakistiscope/Stroboscope (revolving disc), the Zoetrope (revolving drum) and the Praxinoscope (mirror-reflexive revolving drum), and in 1892 the Projection-Praxinoscope presented firstly the moving pictures (animation) on the screen. According to the research of psychology and physiology in the early 20th century it has been recognized that the 'afterimage effect' theory is not sufficient to explain the perception of illusion of movement from the moving images which is closely related to the particularity of the visual perception system of the human eyes. Since then, the Phi-phenomenon suggested 1912 by the Gestalt psychologist, Max Wertheimer (1880-1943), is regarded as the most persuasive theory until now, although it is still imperfect.

Science Instrument Development for the Giant Magellan Telescope

  • Jaffe, Daniel T.
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.55.1-55.1
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    • 2010
  • The Giant Magellan Telescope (GMT) is a 24.5m diameter optical/infrared telescope. Its seven 8.4m primary mirrors give it a collecting area equivalent to a 21.4m filled aperture. The ten GMT partners are constructing the telescope at the Las Campanas Observatory in Chile with first light planned for the end of 2018. In this paper, we describe the plans for the first-generation focal plane instrumentation for the telescope. The GMTO Corporation has solicited studies for instruments capable of carrying out the broad range of objectives outlined in the GMT Science Case. Six instruments have been selected for 14 month long conceptual design studies. We describe the features of these instruments and give examples of the major science questions that they can address.

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Comparison Study of Numerical Simulations Associated with Emission Conditions during Asian Dust Events

  • Kim, Yoo-Keun;Song, Sang-Keun;Jeong, Ju-Hee
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.518-519
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    • 2003
  • Many studies of Asian dust have been undertaken to investigate dust sources, their transport and deposition mechanisms, their optical and chemical properties, and their physical characteristics. These studies have used meteorological parameters, optical thickness, and mineral compositions derived from satellite images, lidar, sunphotometer, and other ground-based instruments in East Asia (Chun et al., 2001; Murayama et al., 2001). (omitted)

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