Hello!
white noise dispersion maps are approximately sqrt(3) times lower in WMAP coadded 3yr than in single 1yr maps.
somebody knows how much is this factor for the 1/f noise?
Thanks
1/f noise in WMAP 3yr data
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carlos monteserin
- Posts: 1
- Joined: February 08 2007
- Affiliation: IFCA (Santander,Spain)
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Tom Crawford
- Posts: 8
- Joined: December 29 2004
- Affiliation: University of Chicago
1/f noise in WMAP 3yr data
There are only two reasons why the 1/f contributions wouldn't also be [tex]\sqrt{3}[/tex] lower:
1) The amplitude of the 1/f sources changed appreciably over years two and three.
2) The sources of 1/f aren't really noise (i.e., they're coherent in some basis that matters to the instrument), and so they don't integrate down as [tex]\sqrt{N}[/tex].
Given the observed stability of the instrument, I think 1) is unlikely, and 2) is something that I think the WMAP team has checked pretty thoroughly. So I think you're probably safe in assuming that the 1/f scales the same way the white noise does.
(Of course, I'm not on the WMAP team, so there may be something important that I'm missing.)
1) The amplitude of the 1/f sources changed appreciably over years two and three.
2) The sources of 1/f aren't really noise (i.e., they're coherent in some basis that matters to the instrument), and so they don't integrate down as [tex]\sqrt{N}[/tex].
Given the observed stability of the instrument, I think 1) is unlikely, and 2) is something that I think the WMAP team has checked pretty thoroughly. So I think you're probably safe in assuming that the 1/f scales the same way the white noise does.
(Of course, I'm not on the WMAP team, so there may be something important that I'm missing.)