• Title/Summary/Keyword: Optical observation

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OBSERVATION SYSTEM OF SOLAR FLARE TELESCOPE (태양플레어망원경의 관측 시스템)

  • Park, Young-Deuk;Moon, Yong-Jae;Jang, Be-Ho;Sim, Kyung-Jin
    • Publications of The Korean Astronomical Society
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    • v.12 no.1
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    • pp.35-45
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    • 1997
  • SOFT($\underline{So}lar\;\underline{F}lare\;\underline{T}elescope$) installed at BOAO(Bohyunsan Optical Astronomy Observatory) is purposed for observing solar active regions using four refractors on single mount with a $400"\times300"$ field of view: Two refractors with a diameter of 15cm(f15) are observe the white light and $H\alpha$, and the other two refractors with a diameter of 20cm(f8) are observe the magnetic field distribution and Doppler shifts at the solar chromosphere. Three Lyot filters, one of the most important observational instruments, are installed on the optical rails for VMG, LMG, and $H\alpha$ that possible to very narrow pass band observation under high precision stability of temperature. From the combination of KD*P and quarter wave plate in the Lyot filter possible observe the magnetic fields strength and doppler shifts by using the characteristics of polarization components. In this paper, we introduce the basic characteristics, optical system, and monitor system of the SOFT.

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Stellar Source Selections for Image Validation of Earth Observation Satellite

  • Yu, Ji-Woong;Park, Sang-Young;Lim, Dong-Wook;Lee, Dong-Han;Sohn, Young-Jong
    • Journal of Astronomy and Space Sciences
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    • v.28 no.4
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    • pp.273-284
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    • 2011
  • A method of stellar source selection for validating the quality of image is investigated for a low Earth orbit optical remote sensing satellite. Image performance of the optical payload needs to be validated after its launch into orbit. The stellar sources are ideal source points that can be used to validate the quality of optical images. For the image validation, stellar sources should be the brightest as possible in the charge-coupled device dynamic range. The time delayed and integration technique, which is used to observe the ground, is also performed to observe the selected stars. The relations between the incident radiance at aperture and V magnitude of a star are established using Gunn & Stryker's star catalogue of spectrum. Applying this result, an appropriate image performance index is determined, and suitable stars and areas of the sky scene are selected for the optical payload on a remote sensing satellite to observe. The result of this research can be utilized to validate the quality of optical payload of a satellite in orbit.

Microstructural Observation of Phase Change Optical Disk by TEM (투과전자현미경을 이용한 상전이형 광디스크의 미세조직 관찰)

  • Kim, Soo-Chul;Kim, Gyeung-Ho
    • Applied Microscopy
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    • v.29 no.4
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    • pp.493-498
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    • 1999
  • With increasing demand for fast and reliable, yet economical data storage devices, the role of optical disk technology is becoming more important. In recent years, advanced laser technology combined with new materials has given the competitive edge over the traditional magnetic memory devices both in memory capacity and reliability of data retrieval. Continuing effort is being put into developing smaller and more complex structures for optical disks to increase their memory density. Characterization of such multilayered structure requires not only high spatial resolution for observation but also laborious specimen preparation. In this paper, the method of preparing optical disk specimens for TEM characterization is described in detail. The microstructural features in optical disks observed by TEM are also discussed.

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Measurement of optical flow using horn and anandan techniques (Horn과 Anandan기법을 이용한 Optical flow 측정)

  • 송석진;남기곤;이장명
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.685-688
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    • 1998
  • Measurement of optical flow is a core problem of matching through the analysis of image sequences. In this paper, horn's and anandan's techniques are analyzed to derive a better technique for matching. Experimental results show that Horn's technique has low accuracy in measuring the velocity of optical flow while anandan's technique has poor performaance for diverging images. Based upon this observation, a new technique for the measurement of optical flow is proposed.

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