The 327 tsys measurements are plotted vs ra,dec and
galactic l,b to see how much the system temperature varies with sky
position. The polA,polB tsys difference are also plotted:
13dec10: Tsys vs ra/dec and Tsys vs
galLong/galLat 07may09 - 13dec10. (top)
Tsys data from 07may09 thru 13dec10 was plotted vs
ra,dec and galactic l/b to show
the portion of Tsys that is coming from the sky. Only data with zenith
angle below 15 degrees was used (to not include the tsys za variation).
The
increase at ra=6 is the anticenter. The peak at 19:00 is the inner
galaxy.
The gradual increase starting at 12 is
probably the north galactic spur
PolB is higher and it has much more
scatter than polA.
Page 2: tsys vs galactic l,b
Top shows the galactic lat, longitude of
the observations
fig 2,3 tsys vs gal long and lat.
Page 3: TsysPolB - TsyspolA
top vs ra
center vs gal long
bottom: vs time
the median difference is 25 Kelvins +/- 9
K
Summary:
The galaxy can increase Tsys polA from 80K to around 180 K.
PolB is about 25 K higher than pola with a much larger scatter
than polA
We don't know if this is a Cal or real tsys problem.
Back in jun08 the calibration data showed TsysB about 10K higher
than polA.
processing:
x101/121013/tsysplotradec.pro
07may09: Tsys vs
ra/dec and Tsys vs
galLong/galLat. (top)
Tsys data from 13jun08 (start of 327 cooled
receiver) thru 07may09 was plotted vs ra,dec and galactic l/b to show
the portion of Tsys that is coming from the sky. Only data with zenith
angle below 15 degrees was used (to not include the tsys za variation).