• Title/Summary/Keyword: Science and Technology Space

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Preflight Calibration Results of Wide-Angle Polarimetric Camera (PolCam) onboard Korean Lunar Orbiter, Danuri

  • Minsup Jeong;Young-Jun Choi;Kyung-In Kang;Bongkon Moon;Bonju Gu;Sungsoo S. Kim;Chae Kyung Sim;Dukhang Lee;Yuriy G. Shkuratov;Gorden Videen;Vadym Kaydash
    • Journal of The Korean Astronomical Society
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    • v.56 no.2
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    • pp.293-299
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    • 2023
  • The Wide-Angle Polarimetric Camera (PolCam) is installed on the Korea's lunar orbiter, Danuri, which launched on August 5, 2022. The mission objectives of PolCam are to construct photometric maps at a wavelength of 336 nm and polarization maps at 461 and 748 nm, with a phase angle range of 0°-135° and a spatial resolution of less than 100 m. PolCam is an imager using the push-broom method and has two cameras, Cam 1 and Cam 2, with a viewing angle of 45° to the right and left of the spacecraft's direction of orbit. We conducted performance tests in a laboratory setting before installing PolCam's flight model on the spacecraft. We analyzed the CCD's dark current, flat-field frame, spot size, and light flux. The dark current was obtained during thermal / vacuum test with various temperatures and the flat-field frame data was also obtained with an integrating sphere and tungsten light bulb. We describe the calibration method and results in this study.

Parking Space Detection based on Camera and LIDAR Sensor Fusion (카메라와 라이다 센서 융합에 기반한 개선된 주차 공간 검출 시스템)

  • Park, Kyujin;Im, Gyubeom;Kim, Minsung;Park, Jaeheung
    • The Journal of Korea Robotics Society
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    • v.14 no.3
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    • pp.170-178
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    • 2019
  • This paper proposes a parking space detection method for autonomous parking by using the Around View Monitor (AVM) image and Light Detection and Ranging (LIDAR) sensor fusion. This method consists of removing obstacles except for the parking line, detecting the parking line, and template matching method to detect the parking space location information in the parking lot. In order to remove the obstacles, we correct and converge LIDAR information considering the distortion phenomenon in AVM image. Based on the assumption that the obstacles are removed, the line filter that reflects the thickness of the parking line and the improved radon transformation are applied to detect the parking line clearly. The parking space location information is detected by applying template matching with the modified parking space template and the detected parking lines are used to return location information of parking space. Finally, we propose a novel parking space detection system that returns relative distance and relative angle from the current vehicle to the parking space.

Near-Infrared Imaging Spectrometer onboard NEXTSat-1

  • Jeong, Woong-Seob;Lee, Dae Hee;Moon, Bongkon;Park, Kwijong;Park, Sung-Joon;Pyo, Jeonghyun;Park, Youngsik;Kim, Il-Joong;Park, Won-Kee;Kim, Mingyu;Lee, Duk-Hang;Nam, Ukwon;Han, Wonyong;Im, Myungshin;Lee, Hyung Mok;Lee, Jeong-Eun;Shin, Goo-Hwan;Chae, Jangsoo
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.70.1-70.1
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    • 2013
  • New space program for "Next-Generation Small Satellite (NEXTSat)" launched last year after the success of the series of Science & Technology Satellite (STSAT). KASI proposed the near-infrared imaging spectrometer as a scientific payload onboard NEXTSat-1. It was selected as one of two scientific payloads. The approved scientific payload is the near-infrared imaging spectrometer for the study of star formation history (NISS). The efficient near-infrared observation can be performed in space by evading the atmospheric emission as well as other thermal noise. The observation of cosmic near-infrared background enables us to reveal the early Universe in an indirect way through the measurement of absolute brightness and spatial fluctuation. The detection of near-infrared spectral lines in nearby galaxies, cluster of galaxies and star forming regions give us less biased information on the star formation. In addition, the NISS will be expected to demonstrate our technologies related to the development of the Korea's leading near-infrared instrument for the future large infrared telescope, SPICA.

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Communications Link Design and Analysis of the NEXTSat-1 for SoH File and Mission Data Using CAN Bus, UART and SerDesLVDS

  • Shin, Goo-Hwan;Chae, Jang-Soo;Min, Kyung-Wook;Sohn, Jong-Dae;Jeong, Woong-Seob;Lee, Dae-Hee
    • Journal of Astronomy and Space Sciences
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    • v.31 no.3
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    • pp.235-240
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    • 2014
  • The communications link in a space program is a crucial point for upgrading its performance by handling data between spacecraft bus and payloads, because spacecraft's missions are related to the data handling mechanism using communications ports such as a controlled area network bus (CAN Bus) and a universal asynchronous receiver and transmitter (UART). The NEXTSat-1 has a lot of communications ports for performing science and technology missions. However, the top level system requirements for the NEXTSat-1 are mass and volume limitations. Normally, the communications for units shall be conducted by using point to point link which require more mass and volume to interconnect. Thus, our approach for the novel communications link in the NEXTSat-1 program is to use CAN and serializer and deserializer low voltage differential signal (SerDesLVDS) to meet the system requirements of mass and volume. The CAN Bus and SerDesLVDS were confirmed by using already defined communications link for our missions in the NEXTSat-1 program and the analysis results were reported in this study in view of data flow and size analysis.

BITSE Preliminary Result and Future Plan

  • Bong, Su-Chan;Yang, Heesu;Lee, Jae-Ok;Kwon, Ryun Young;Cho, Kyung-Suk;Kim, Yeon-Han;Reginald, Nelson L.;Yashiro, Seiji;Gong, Qian;Gopalswamy, Natchumuthuk;Newmark, Jeffrey S.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.58.2-58.2
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    • 2019
  • BITSE is a technology demonstration mission to remotely measure the speed, temperature, and density of the solar wind as it forms as close as 3 Rs. BITSE obtained coronal images during its one day flight above more than 99% of the atmosphere, and calibration data are taken in the laboratory as well as during the flight. As the linearly polarized K-corona is much fainter than other bright sources like diffraction, sky, and F-corona, a careful data reduction is required to obtain reliable scientific results. We will report status of the obtained data, the reduction progress, and future plan.

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A STUDY ON GNSS TECHNOLOGY STRATEGIES WITH ANALYSIS OF INFORMATION (정보분석을 통한 위성항법 기술분야 전략 연구)

  • Kim, Sun-Woo;Cho, Jung-Ho
    • Bulletin of the Korean Space Science Society
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    • 2007.10a
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    • pp.129-134
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    • 2007
  • As quantity of information has been increased rapidly, the importance of efficient information analysis system has increased. This research suggests the direction of GNSS (Global Navigation Satellite System) technology strategies with information analysis on SCI Expanded DB. Exactly, it analyzes paper map and network structure between nations, between institutes and between authors. As a conclusion, it suggests strategies to take an opportunity for emerging technology and secure a leading position.

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KITSAT-1 COSMIC RAY EXPERIMENT-INITIAL RESULTS

  • Min, K.W.;Kim, S.H.;Shin, Y.H.;Choi, Y.W.
    • Journal of Astronomy and Space Sciences
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    • v.10 no.2
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    • pp.103-112
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    • 1993
  • The KITSAT-1 was successfully launched on August 11, 1992, into a near circular, 1300-km-high orbit with an $66^{\circ}$inclination. The satellite carries a solid state detector module to measure the high energy particle flux originating mostly from the inner radiation belt. We describe here the objectives of the experiment, the detector structure, and the preliminary result.

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