Hi Walt,
Thanks for discovering that there are two periods (Feb and Nov 2012)
when CMB tags included in the standard BICEP2 analysis coincide with the
DSL mast being up for Keck cals. At least your post tells us that the G
phases--the ones where B2 points toward the mast and the signal is seen
clearly--already seem to be caught by existing cuts.
You say "For the early Nov. 2012 period it's not at all clear when
exactly the mast was raised." I checked the daily emails Zak and Colin
were sending to keckarray list from Pole during that period, and Zak's
"Pole notes: Nov 7" email says that on Monday, Nov 5:
"DSL mast up with ze choppa, figured out communication over fiber
That's their first mention of raising the mast. Assuming they didn't
start before breakfast, I think that means the mast went up midway
through phase F at the earliest--so less than one full phase of B2 tags
should be potentially affected. Colin or Zak can confirm.
There seem to be way more B2 tags during the Feb 2012 period. Most of
that period is ze choppa. I am far less worried about the thermal
source than when an amplified source is up there--for the thermal source
I'd guess scansets with AZ far from the mast should be quite safe. Do
we need to put more effort into reconstructing what days the RPS/BSNS
was being used? I am not opposed to cutting all the B2 2012 Feb CMB
data if that is the easiest.
John
On 9/28/13 3:02 AM, Walt Ogburn wrote:
In searching for satellite contamination in the CMB
data, I keep
finding another time-varying source of large az-fixed signal: the DSL
mast. This has been raised and lowered at various times for summer
calibrations. I haven't found a clear record of when exactly it was up,
so I've tried to reconstruct it as well as I can from various logs. We
could consider cutting the affected tags. It's certainly necessary to
exclude them for further studies of the satcom signal.
http://bicep0.caltech.edu/~spuder/analysis_logbook/analysis/20130927_dsl_ma…
- Walt
_______________________________________________
Bicep2-list mailing list
Bicep2-list(a)lists.fas.harvard.edu
https://lists.fas.harvard.edu/mailman/listinfo/bicep2-list
--
___________________________________________________________________
John Kovac jmkovac(a)cfa.harvard.edu
Associate Professor, Harvard University Astronomy Department
160 Concord Ave rm 310, Cambridge MA 02138, 617-496-0611