• 제목/요약/키워드: ccd

검색결과 2,857건 처리시간 0.036초

H$\bate$CCD 측광의 정확도 (THE ACCURACY OF H$\bate$CCD PHOTOMETRY)

  • 김철희;김승리
    • Journal of Astronomy and Space Sciences
    • /
    • 제11권2호
    • /
    • pp.208-231
    • /
    • 1994
  • We have undertaken CCD observations of fie이 standard stars with H$\beta$ photometric system to investigate the reliability of H$\beta$ CCD photometry. Flat fielding with dome flat and sky flat for H$\beta$w and H$\beta$n filter was compared with that of B filter in UBV system and, from these, we have not found any difference. It was confirmed that there is a good linear relationship between our H$\beta$ values observed with 2.3m reflector and standard values. However, H$\beta$ values observed with 60cm reflector at Sobaeksan Astronomy Observatory showed very poor relationship. To investigate the accuracy of H$\beta$ CCD photometry for fainter objects, open cluster NGC2437 was observed and reduced with DoPHOT, and the results were compared with those for photoelectric photometry of Stetson(1981).

  • PDF

CCD Pixel Correction Table Generation for MSC

  • Kim Young Sun;Kong Jong-Pil;Heo Haeng-Pal;Park Jong-Euk;Paik Hong-Yul
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
    • /
    • pp.471-474
    • /
    • 2004
  • Not all CCD pixels generate uniform value for the uniform radiance due to the different process of manufacture and each pixel characteristics. And the image data compression is essential in the real time image transmission because of the high line rate and the limited RF bandwidth. This pixel's nonuniformity and the loss compression make CCD pixel correction necessary in on-orbit condition. In the MSC system, the NUC unit, which is a part of MSC PMU, is charge of the correction for CCD each pixel. The correction is performed with the gain and the offset table for the each pixel and the each TDI mode. These correction tables are generated and programmed in the PMU Flash memory through the various image data tests at the ground test. Besides, they can be uploaded from ground station after onorbit calibration. This paper describes the principle of the table generation and the test way of the non-uniformity after NUC

  • PDF

비 가시 환경에서의 LRF와 CCD 카메라의 성능비교 (Performance Comparison of the LRF and CCD Camera under Non-Visibility (Dense Aerosol) Environments)

  • 조재완;최영수;정경민
    • 제어로봇시스템학회논문지
    • /
    • 제22권5호
    • /
    • pp.367-373
    • /
    • 2016
  • In this paper, range measurement performance of LRF (Laser Range Finder) module and image contrast of color CCD camera are evaluated under the aerosol (high temperature steam) environments, which are simulated severe accident conditions of the LWR (Light-Water-Reactor) nuclear power plant. Data of LRF and color CCD camera are key informations, which are needed in the implementation of SLAM (Simultaneous Localization and Mapping) function for emergency response robot system to cope with urgently accidents of the nuclear power plant.

소백산천문대 2K CCD 카메라용 관측 프로그램 개발 (AN OBSERVATION PROGRAM FOR THE SOAO 2K CCD CAMERA)

  • 김승리;경재만;권순길;윤재혁
    • 천문학논총
    • /
    • 제16권1호
    • /
    • pp.37-42
    • /
    • 2001
  • We developed an observation program for a 2K CCD camera, which was newly attached at the SOAO (Sobaeksan Optical Astronomy Observatory) 61cm telescope. The program was designed to control the telescope as well as the CCD camera and to monitor the CCD image quality, with very easy under the window-based graphical user interface (GUI). Furthermore, applying the automated differential photometric algorithm, we can obtain the instrumental magnitudes of several variable and comparison stars in real-time. Simultaneous photometry enables us to get precise differential magnitudes of variable stars even if the weather condition is not photometric. This new observation system has been using for many astronomical observations from September, 2001.

  • PDF

CCD 카메라를 이용한 방사선원 추적에 관한 연구 (Study of tracing radiation Using CCD camera)

  • 이승민;이효성;이흥호
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
    • /
    • pp.442-444
    • /
    • 2005
  • 방사선을 센싱하는 센서들에는 어려 종류가 있으며, 그 센서에 따라서 감도나 센싱방식이 다양하다. 본 연구에서는 해상도가 높은 범용 CCD 센서를 이용하여 방사선을 검출하는데, 감도를 높이기 위해서 신실레이터라는 물질을 CCD CHIP 앞에 부착하였고, 들어오는 영상에서 방사선에 반응하여 생기는 백색량을 처리하여 방사선량을 측정할 수 있다는 것을 보여주고 있다. 또한 Panning을 하며 공간상에서 방사선이 가장 많이 나오는 포인터를 제시할 수 있다. 추후 스테레오 카메라 방식을 구현하여 방사선원까지의 거리 산출과 영상을 합성하여 입체화 시키는 연구도 진행할 예정이다. 논 연구의 결과물로 예기치 않은 방사선 사고의 경우 효과적인 사고처리에 활용될 수 있을 것이다.

  • PDF

변위측정을 위한 선형 CCD 센서와 PSD 센서의 성능 비교에 관한 연구 (Study on Comparing the Performance of Linear CCD sensor with PSD sensor for Distance Measurement)

  • 신명관;박기환
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2004년도 하계학술대회 논문집 D
    • /
    • pp.2167-2169
    • /
    • 2004
  • The main concern for a displacement measurement is the performance of a sensor such as speed, resolution, accuracy and so on. The mainly used sensors are a linear CCD(charge coupled device) and a PSD(position sensitive detection) as a non-contact type. The output value of a linear CCD is so sensitive to a temperature change that it needs a cooling device. Additionally, because of its structural problem, there are some limits in resolution and speed, and it needs a complex image processing algorithm. Also, PSD has some disadvantages like sensitivity to environmental lights and nonlinearities. Like this, a linear CCD and PSD have their own characteristics and if we know them well, we can choose the one of the two sensors properly in some applications according to purposes. In this paper, I performed which one is superior to the other among the two sensors in terms of accuracy, resolution, measurement speed, signal to noise ratio.

  • PDF

DEVELOPMENT OF A HIGH SPEED CCD CAMERA SYSTEM FOR THE OBSERVATION OF SOLAR Ha FLARES

  • VERMA V. K.;UDDIN WAHAB;GAUR V. P.
    • 천문학회지
    • /
    • 제29권spc1호
    • /
    • pp.391-392
    • /
    • 1996
  • We have developed and tested a CCD camera (100 $\times$ 100 pixels) system for observing Ha images of the solar flares with time resolution> 25 msec. The 512 $\times$ 512 pixels image of CCD camera at 2 Mpixels/sec can be recorded at the rate of more than 5 frame/sec while 100 $\times$ 100 pixels area image can be obtained 40 frames/sec. The 100 $\times$ 100 pixels image of CCD camera corresponds to 130 $\times$ 130 arc - $sec^2$ of the solar disk.

  • PDF

CQUEAN CCD의 바이어스 특성 분석

  • 최나현;박수종;최창수;박원기;임명신
    • 천문학회보
    • /
    • 제37권1호
    • /
    • pp.70.1-70.1
    • /
    • 2012
  • CQUEAN (Camera for QUasars in EArly uNiverse)은 초기우주천체 연구단(Center for Exploration of Origin of the Universe) 사업에서 개발한 CCD 카메라로서 초기우주의 퀘이사 후보를 찾기 위한 목적으로 설계되었다. CCD를 구동할 때는 픽셀 다이오드의 PN 접합층에 공핍층(depletion layer)을 생성하기위해 역 바이어스 전압을 준다. 이 전압에 의해 CCD를 사용한 관측 시 광이온화와 열이온화 현상에 의해 생성된 전자의 전하값에 추가로 바이어스 값이 읽혀진다. 정확한 CCD 측광 결과를 얻어내기 위해서는 안정된 바이어스를 유지해야 한다. 본 연구에서는 향후 CQUEAN의 보다 정확한 관측 및 데이터 처리에 대비하여 CQUEAN의 바이어스 특성을 분석하여 이 값에 영향을 주는 요인을 찾고 해결책을 논의한다.

  • PDF

MTF 방법에 의한 카메라 렌즈 초점 자동 측정 시스템 개발 (Focal Length Measurement System for Camera Lens using the MTF)

  • 이석원;이동성;박희재;문호균;김영식
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1996년도 춘계학술대회 논문집
    • /
    • pp.264-270
    • /
    • 1996
  • In this paper, a computer automated system has been developed for measuring the focal length of camera lens using the MTF(Modurar Transfer Function) based on the signal processing around a line CCD and autocollimator. An optical Path for the focal length measurement system has been designed around thelight sourec, collimator, camera, mirror and the line CCD. The eyepiece of the collimator is replaced byline CCD, and the mirror is moved along the focal axis by a PC driven step motor. An efficient method has been designed for finding the optimum MTF value for the focal length based on the least squares approach. The developed system is fullycomputer automated: signal transmission to and from the camera, MTF evaluation based on the line CCD, step motor contorl, etc. The developed system has been applied to a practical camera manufacturing process and demonstrated its performance

  • PDF

표적 크기추정 기술 기반의 CCD 영상 표적 정밀 요격 성능 개선 연구 (A Study on the Target Precision Intercept Algorithm based on the Target Size Estimation at CCD Image Sequence)

  • 정윤식;노신백
    • 제어로봇시스템학회논문지
    • /
    • 제21권1호
    • /
    • pp.52-58
    • /
    • 2015
  • In this paper, The ET-MBEF algorithm is presented for CCD imaging seeker. At the imaging seeker, target size information is important factor for accurate tracking. The MBEF algorithm was proposed to estimate target size at IIR seeker. However, the MBEF algorithm can't be applied at CCD imaginary target size estimation. In order to overcome the problem, we propose ET-MBEF algorithm which based on ET (Edge Template) and MBEF algorithm. The performance of proposed method is tested at target intercept scenario. The experiment results show that the proposed algorithm has the accurate target intercept performance.