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: http://www.naic.edu/~phil/calsbh/sbh.html
Дата изменения: Sat Jun 18 01:22:36 2011
Дата индексирования: Tue Oct 2 00:52:06 2012
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sband high (3-4 Ghz receiver)
mar02
The sband high (sbh) receiver covers 3 to 4
Ghz.
It has a quadridge OMT (native linear polarization) and a
ying/kildal
horn. The receiver was installed on the telescope 22mar02.
history
Recent
system performance measurements
Daily
monitoring of Tsys.
Dewar
temperatures
Calibration measurements
Miscellaneous
cal values
History:
09mar04: Measured cal values (new diodes installed 13feb04) using sky
and
absorber
13feb04: shi receiver moved down .8 inches into focus, new cal diodes
installed.
09may03: measured cal values using sky and absorber.
22mar02: receiver installed on telescope
Calibration
measurements:
recent
system
performance measurements
17jun11:
sbh calibration used to measure 1az term of platform.
02jul09: Tsys vs freq
and cal values over entire band.
Feb04-Jun04: sbh GAIN CURVES.
Feb04-Jun04: System performance
of data used for gain curves.
may03-sep03: sbh GAIN CURVES.
may03-sep03: System performance
of data used for gain curves.
08apr02,11apr02
calibration
runs. Performance: gain,tsys,sefd,pnterr,etc..
23mar02: cal and Tsys versus
frequency.
Miscellaneous:
09may03:
resonances
in the sbh receiver.
All measurements by date:
Feb04 to Jun04
fit
GAIN CURVES to calib data. (top...)
link
to gain curve plot
Gain curves were fit to the sband high
calibration
gain data using 13Feb04 through 30jun04. The start of
this epoch was after the als were replaced and the dewar was lower .8
inches
to bring it into focus. The plots show the gain data (black) and the
fits
(red) for 3300, 3500, 3700, and 3825 Mhz. These gain equations were
installed
on 03Jul04 and back data to be valid starting on 13feb04.
- Fig 1 shows the az,za distribution for the data. The fit used a
linear
fit in za up to za=14. Above 14 degrees terms in (za-14)^2 and
(za-14)^3
were included. The fit also included 1az, 2az, and 3az sin, cos
terms.
- Fig 2 plots the gain data and the fit to za. The fit
equation is
plotted with the sigma for the fit (in K/Jy).
- Fig 3 plots the fit residuals (data-fit) vs za.
The routine gainget() or corhgainget() will now
return
the sbh gain for data after 12feb04 from these
equations. The coefficients can be found in the ascii file
data/gain.datR8
(this is provided in the AO idl
distribution for correlator routines). You can also find a copy of
it at AO in /pkg/rsi/local/libao/phil/data/gain.datR8.
processing: x101/sbh/mar04/dogainfit.pro
feb04 thru
jun04 : System performance of data used to compute gain curves. (top...)
Heiles calibration scans done from 13feb04
(new cals, horn lowered) thru 30jun04 were used to measure the
system performance. This data was then used to compute the gain curves
used after 12feb04.
The first set of plots show
the system performance with all frequencies overplotted. The
sources
are identified
by symbol and the frequencies by color.
- Fig 1 shows the distributions on the dish of the measurements.
- Fig 2 has the Gain in Kelvins/Jansky. This relies on the cals and
the
source
flux. Ths next plot is Tsys vs za in Kelvins followed by the
SEFD
(System Equivalent Flux density) in Janskies / Tsys. At the bottom is
the
average beam width in arc seconds.
- Fig 3 plots the coma parameter, first sidelobe height below the
peak,
the
main beam efficiency, followed by the main beam + 1st sidelobe beam
efficiency.
- Fig 4 has the pointing errors in az,za.
The second set of plots has the
data plotted separately for each frequency. The colors and symbols
are used to differentiate the sources. The figures are:
- Fig 1 3300 Mhz Gain,Tsys . 282 points
- Fig 2 3300 Mhz sidelobes,beam efficiencies
- Fig 3 3500 Mhz Gain,Tsys 282 points.
- Fig 4 3500 Mhz sidelobes,beam efficiencies.
- Fig 5 3700 Mhz Gain,Tsys 282 points.
- Fig 6 3700 Mhz sidelobes,beam efficiencies
- Fig 7 3825 Mhz Gain,Tsys 201 points.
- Fig 8 3825 Mhz sidelobes,beam efficiencies
processing: x101/sbh/mar04/doit.pro
May03 to Sep03
fit
GAIN CURVES to calib data. (top...)
link
to gain curve plot
Gain curves were fit to the sband high gain
data from 15may03 through 30sep03. The start of this epoch was
after
the shimmin g of the elevation rails in feb03. The end date was chosen
so that the cal had not drifted too much (see warning below). The plots
show the gain data (black) and the fits (red) for 3300, 3500, 3700, and
3900 Mhz. These gain equations were installed on 10mar04.
- Fig 1 shows the az,za distribution for the data. The fit used a
linear
fit in za up to za=14. Above 14 degrees terms in (za-14)^2 and
(za-14)^3
were included. The fit also included 1az, 2az, and 3az sin, cos
terms.
- Fig 2 plots the gain data and the fit to za. The fit
equation is
plotted with the sigma for the fit (in K/Jy).
- Fig 3 plots the fit residuals (data-fit) vs za.
Warning: The sbh cal was drifting in time (see tsys
plots). During this period it was relatively stable. Use these
curves
outside this region with care. The cals were replaced in feb04.
The routine gainget() or corhgainget() will now
return
the sbh gain for data after 01mar03 from these
equations. The coefficients can be found in the ascii file
data/gain.datR8
(this is provided in the AO idl
distribution for correlator routines). You can also find a copy of
it at AO in /home/phil/idl/data/gain.datR8.
processing: x101/sbh/mar03/dogainfit.pro
may03 thru feb04 : System
performance
of data used to compute gain curves. (top...)
Heiles calibration scans done from 15may03
(after shimming) thru 30sep03 were used to measure the
system performance. This data was then used to compute the gain curves
used after 01mar03.
The first set of plots show
the system performance with all frequencies overplotted. The
sources
are identified
by symbol and the frequencies by color.
- Fig 1 shows the distributions on the dish of the measurements.
- Fig 2 has the Gain in Kelvins/Jansky. This relies on the cals and
the
source
flux. Ths next plot is Tsys vs za in Kelvins followed by the
SEFD
(System Equivalent Flux density) in Janskies / Tsys. At the bottom is
the
average beam width in arc seconds.
- Fig 3 plots the coma parameter, first sidelobe height below the
peak,
the
main beam efficiency, followed by the main beam + 1st sidelobe beam
efficiency.
- Fig 4 has the pointing errors in az,za.
The second set of plots has the
data plotted separately for each frequency. The colors and symbols
are used to differentiate the sources. The figures are:
- Fig 1 3300 Mhz Gain,Tsys . 295 points
- Fig 2 3300 Mhz sidelobes,beam efficiencies
- Fig 3 3500 Mhz Gain,Tsys 294 points.
- Fig 4 3500 Mhz sidelobes,beam efficiencies.
- Fig 5 3700 Mhz Gain,Tsys 293 points.
- Fig 6 3700 Mhz sidelobes,beam efficiencies
- Fig 7 3900 Mhz Gain,Tsys 294 points.
- Fig 8 3900 Mhz sidelobes,beam efficiencies
processing: x101/sbh/mar03/doit.pro
08apr02,11apr02:
calibration runs. (top...)
Calibration runs were done on 08apr02
(B0038+328,B0316+162:CTA21,B0518+165:3C138)
during the day and on 11apr02 (B1328+254,B1535+139) using the standard
heiles
calibration scans. Data was taken at 3300, 3500, 3700, and
3900
Mhz (Note: the cal values at 3900 Mhz were extrapolated from measured
cal
values at 3700 Mhz). The plots show the
system performance.
- Figure 1 show the gain in K/Jy, Tsys in K, SEFD in Jy/Tsys, and
the
average
beam width. Sources are plotted with different symbols. Color is used
separate
the 4 frequencies.
- Figure 2 plots the coma parameter, first sidelobe height relative
to
the
peak in db's, main beam efficiency, and the main beam plus first
sidelobe
beam efficiency.
- Figure 3 plots the pointing error in za (versus za,az), pointing
error
in az (versus za, az), and the total pointing error
(sqrt(azerr^2+zaerr^2)
versus za, and az. At top is plotted the mean and rms for the zaerr,
azerr,
and total error.
processing: x101/sbh/apr02/doit.pro
23mar02:
cal
and tsys versus frequency. (top...)
While tracking blank sky, 5 second cal on/offs were
done across the frequency range 3 Ghz to 3.7 Ghz using the high
correlated
cal. 3.7 to 4 Ghz was not covered because we do not yet have cal values
for this range. When the cals were measured on the hill with the horn
pointing
at the sky, the 3.7 to 4 Ghz range was contaminated by the satellite tv
band (looking straight up, the beam is +/- 60 degrees ). On the
telescope
the narrow beam limits how often we see a satellite.
The plots show cal
value versus frequency and the system temperature versus frequency.
It looks a bit strange that the shape of the high and low cal differ by
so much for some of the cals (since they differ by a 10db coupler).
processing: x101/020322/doitcals.pro
home_~phil