Time-Delayed Integration/ Drift scanning

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Time-Delayed Integration/Drift scanning

• William van Altena
• Yale University
• Basic Astrometric Methods
• Yale University
• July 18-22, 2005

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The Bucket Brigade
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Observed strip of the sky
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Sample Drift Scan
RA
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Geometry of Scan Across CCD
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Coordinates on the CCD
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The Celestial Sphere
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Declination Degradation
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Normal Declination Limits
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Going to Higher Dec. Limits
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Drift-scanning
star track
star trail
25.0 cm
North lt---------------- -----------gt South
West lt----- -------gt East
19.3 cm
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Relative Reductions
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Aberration of Starlight
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Declination Overlap Errors
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RA Overlap Errors
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Precision of scan to scan registration
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Sources of Errors
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Reference Star Catalog Errors
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Schmidt Telescope Errors
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Dynamic Range
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Error versus Magnitude
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Error versus Zenith Distance
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Precision Limits
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Accuracy Limits the Atmosphere
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Precision Limits the Atmosphere
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Precision versus Aperture
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Worlds Largest CCD Cameras
Megacam 36 2048x4612
Palomar-Quest 112 600x2400
19 cm
Sloan 30 2048x2048
SuprimeCam 10 2048x4096
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The Sloan Camera (SDSS)
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Palomar/Quest Camera
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Palomar Quest
Orion Nebula Driftscan BRI-composite, 140-sec
exposure
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