DAWN kamera kalibrci

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DAWN kamera kalibráció

• Dr. Kovács Gábor

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A Dawn projekt
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A DAWN kamera optikai rendszere
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Dawn kamera
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The classic method

• Bias correction
• Electronic offset, and noise correction
• Dark correction
• Compensate for the CCD dark current
• Flat field correction
• The CCD pixel to pixel non-uniformity correction

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Stray lights, reflections

• Stray light analysis without CCD
• CCD surface reflection 38!
• The majority of internal stray light comes from
  the filter reflection
• Scenery dependency

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CCD reflection

• The CCD reflection is neither diffuse (Lambert),
  nor specular
• The CCD acts as a diffraction grating
• The incoming light is split into several dozen
  diffraction orders
• The angular difference

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Residual charges

• The short exposure images exhibited significant
  residual charge effect
• The effect is dependant on
• Illumination intensity
• CCD temperature
• Individual pixels
• Individual detectors