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Is the striped pattern in SDSS video due to drift-scan observation?

I'm processing SDSS photometric data for a galaxy evolution project and the striping is a consistent feature in the raw frames. Understanding its instrumental origin is key for correcting artifacts and assessing data quality. Can you confirm that this pattern is fundamentally tied to the SDSS's scan mode, and briefly explain the mechanism?

 

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By Rinku Answered 1 year ago

Yes, you've correctly identified the cause. The SDSS didn't use a traditional point-and-track method. Instead, it employed a drift-scan, or time-delay integration (TDI), mode. The telescope was fixed, allowing the sky to drift across its focal plane, which was lined with long, rectangular CCD arrays. As the sky image moved, the charge in each CCD pixel was electronically shifted at precisely the same rate to follow it. This creates the iconic long, continuous stripes of data. I have worked with this data for years, and understanding this scan law is the first step in any robust reduction pipeline to correct for photometric and astrometric offsets between adjacent stripes.

 

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