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Filtering Errors

Filtering Errors

April 20, 2001


HZ43 (obsid 59) spectrum, with varying filtering levels. Red curve shows the problem with bit 21 filtering. All HRC-S data processed prior to July 2, 2001 are affected. (Figure by D. Pease.)


Upper panel: Spectra normalized to no-filtering spectrum, showing combined effect of PI and Status-Bit filtering without bit 21. Status-Bit and Light PI filter remove ~2% of valid x-ray events, SB/Medium remove ~4%, SB/Heavy remove ~9% out to 135 Angstroms, but more at longer wavelengths, and with noticeable periodic dips.

Lower panel: Spectra normalized to no-filtering spectrum, showing combined effect of PI and Status-Bit filtering including bit 21. Status-Bit #21 removes an extra 5% of valid x-ray events at all wavelengths, with periodic dips that remove roughly 20-40%. (Figures by D. Pease.)


Additional plots confirm the effect of status bit 21 at shorter wavelengths, on the central HRC-S segment.


Last modified: 06/14/02



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