SKY BACKGROUND

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SKY BACKGROUND CALIBRATION and CORRECTION
José Eduardo Costa
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Correction by Sky Background

• Standard procedure
• Correction STAR SKY

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CoRoT Sky Background Windows

• SISMO (1s)
• 5 windows / CCD
• 50x50
• EXO (32s)
• 10 windows / CCD
• 10x10
• EXO (512s)
• 40 windows / CCD
• 10x10

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Sky Background
SKY BACKGROUND ADJACENT SKY PARASITE
LIGHT PARASITE LIGHT

• Straylight from the Earth
• SAA
• Moonlight
• Other sources of light
• Diffusion and reflection

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Straylight From Earth

• h 896 km
• P 1h 42.9min
• f 162 uHz

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Straylight and Orbital Position
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South Atlantic Anomaly (SAA)
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Effects on SISMO and EXO
SISMO
EXO
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Corrections of the Sky Background

• Correction On Board
• Outline points (cosmic rays)
• Correction On Ground
• Outline points, SAA and Discontinuity
• Sky Background Gradient

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Correction On Board
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Correction of Outline Points and Discontinuity
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Asymmetrical Optical System
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Non-Homogeneous Sky Background
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Residual Sky Light Curve
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SBC Program
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Modelization of the Sky Background Gradient
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Sky Background Characterization
f(x,y) cte
Homogeneous
Sky Background
Regular
f(x,y t)
Non-homogeneous
Irregular
Local Triang.
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Irregular Sky BackgroundLocal Triangularization
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SBC Sky Background Gradient
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Thank you
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Zodiacal Light
(scattering of the solar light by thin particles
of dust)