• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.379-388
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• 2007

Modulation Transfer Function (MTF) of satellite image is an important performance index in satellite image applications. Therefore MTF performance is assessed using satellite image for the ground target during LEOP phase after launch. But the MTF performance assessment using the ground target can be affected by imaging conditions such as cloud and weather. In this paper system requirements and satellite operation for assessing MTF performance of satellite image using stellar sources are proposed. Satellite capability in collecting stellar sources using the satellite which is designed for earth observation and satellite image usefulness for assessing MTF performances were analyzed. The proposed approach will be useful to assess MTF performance of earth observation satellite in lower earth orbit.

• Proceedings of the KSRS Conference
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• v.2
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• pp.582-585
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• 2006

Augustine volcano is an active stratovolcano located southwest of Anchorage, Alaska. Augustine volcano experienced seven significantly explosive eruptions in 1812, 1883, 1908, 1935, 1963, 1976, and 1986, and a minor eruption in January 2006. To measure ground surface deformation of Augustine volcano, we applied satellite radar interferometry with ERS-1/2 and ENVISAT SAR images acquired from three descending and three ascending satellite tracks. Multiple interferograms are stacked to reduce artifacts due to changes in atmospheric condition and retrieve temporal deformation sequence. For this, we used Least Square (LS) method for reducing atmospheric effects and Singular Value Decomposition (SVD) method for the retrieval of a temporal deformation sequence. Interferograms before 2006 eruption show about 3 cm/year subsidence by contraction of pyroclastic flow deposits from the 1986 eruption. Interferograms during 2006 eruption do not show significant deformation around volcano crater. Interferograms after 2006 eruption show again a several cm subsidence by compaction and contraction of pyroclastic flow deposits for a few months. This study demonstrates that satellite radar interferometry can monitor deformation of Augustine volcano to help understand the magma plumbing system driving surface deformation.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.78.1-78.1
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• 2021

A Lunar observatory not only provides ideas and experiences for space settlements from the Moon to Mars, but also puts the telescope in an optimal position to compete with space telescopes. Earth observation on the Moon's surface has the advantage of no atmospheric scattering or light pollution and is a stable fuel-free observation platform, allowing all longitude and latitude of the Earth to be observed for a month. Observing the entire globe with a single observation instrument, which has never been attempted before, and calculating the global albedo will significantly help predict the weather and climate change. Spectropolarimetric observations can reveal the physical and chemical properties of the Earth's atmosphere, track the global distribution and migration path of aerosols and air pollutants, and can also help detect very small space debris of which the risk has increased recently. In addition, the zodiacal light, which is difficult to observe from Earth, is very easy to observe from the lunar observatory, so it will be an opportunity to reveal the origin of the solar system and take a step closer to understanding the exoplanet system. In conclusion, building and developing a lunar observatory will be a groundbreaking study to become the world's leader that we have never tried before as a first step in expanding human experience and intelligence.

• Journal of the Korean earth science society
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• v.32 no.5
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• pp.514-520
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• 2011

As homework, a total of 32 seventh grade science-gifted students were asked to observe the moon at daily intervals for one month duration. They were also asked to take the photos and to record relevant variables in a given format. The purpose of the task was to investigate what students thought, as they observed the moon. The results show that students paid attention mainly to the position of the moon relative to other variables such as the date in the lunar calendar, the observer's position on the earth, and the position of the sun. Overall students' response implied that students did not observe the lunar phase in relation with relevant variables. Some reponses from students show common misconceptions such as the cause of the lunar phase to reflect the shadow of the earth. However, some responses reveal students' idea that has been rarely reported in the previous researches. For example, some students drew the moon to revolve in the opposite direction. Significant number of students drew the sun's position to be due west before the full moon and due east after the full moon. Few students recognized the relation between the time of observation and observer's position on the earth. The results of current research suggest that not only the education but also the research needs to be expanded to consider informal environment such as the actual field conditions.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.141-144
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• 2012

A mobile Rayleigh Doppler wind LIDAR at an eye-safe wavelength of 355 nm incorporating double-edge technique with triple-channel Fabry-Perot etalon is developed for wind measurement from 5 to 40km. The structure of this LIDAR system is described. An intercomparsion experiment with rawinsonde is made, showing good agreement with expected measurement accuracy. A continuous observation of stratosphere wind field for several days with temporal resolution of 15 min and spatial resolution of 200 m from 5 to 40 km is presented, demonstrating the stability and robustness of the LIDAR. A stratospheric quasi-zero wind layer can be found at around 20 km with a direction change from east to west evident in the continuous observation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.686-689
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• 2006

SAC is earth observation camera being developed by satrec initiative. It provides 10m in multi-spectral channel and 50km swath width at 685km altitude. The EQM of SAC has been developed and tested. In this paper, the procedure and result of the vibration test of SAC to validate structural design and to verify structural toughness are described.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.14-19
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• 1998

The MUBEX (MUtsu Bay sea surface temperature validation EXperiment) campaign has been held from 1995 to 1997 in summer. During the MUBEX campaign, a thermal infrared camera (TIC) installed on a research vessel, which was also equipped with other various observation devices, was intensively used to observe microscopic structure of sea skin surface temperature (SSST) behavior. We have now a total number of 500,000 images observed by the TIC under various weather conditions, i.e., very calm or wavy sea condition, and clear, patchy or cloudy sky condition. In this paper, we show typical SSST patterns observed by the TIC, and describe the result of statistical analysis of SSST.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.902-912
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• 2011

The purpose of this study was to investigate the effects of teaching based on analysis of a hierarchy of the concepts associated with astronomical observation as well as each learner's status of knowledge through analytical methods of the knowledge state. A test instrument was developed to measure high school students' concepts associated with astronomical observation before instruction. The learners' psychological hierarchy associated with astronomical observation that the participants possessed showed the order of 'motion of the earth${\rightarrow}$coordinate system${\rightarrow}$astronomical observation (mechanism of the telescope${\rightarrow}$installation of the telescope${\rightarrow}$observation through the telescope)', and so was the hierarchy of teaching (70.6%). The learners' knowledge state that is supposed to be similar each other in the ability of observing celestial bodies was different even through they scored the same on the concept test. There were cases with the knowledge state well-structured and not well-structured, which suggests that differentiated instruction with appropriate teaching-learning prescriptions be prepared. An analysis of the knowledge state can play the role of both preparing individualized learning prescriptions and formative evaluation. In the unit dealing with astronomical observation of Earth ScienceI, teaching according to the psychological hierarchy of learners rather than the order in which the textbook syllabi were presented scored significantly higher (p<0.05) on the level of concept achievements. This result suggests that the teacher can help students achieve more efficient in learning by analyzing the learner's knowledge state and reordering the syllabi of the textbook in teaching the concepts associated with astronomical observation.

• Bulletin of the Korean Space Science Society
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• 1993.04a
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• pp.14.1-14
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• 1993

BV observation of AW Cam (BD.69'0389, HD48049, Bv412) have been carried outusing a CCD Camera attached to 61-cm telescope, at Sobaek mountain Astronomical Observatory. BD 159'0385 were employed for the comparison. A total of 350obserrations were obtained during 3 nights between Jan. 28 and Feb. 19 1993. The light curve have been analyzed by the method of Wilson and Devinney different ialcorrection. The results were compared with the previous solutions.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.546-548
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• 2007