Links to the plots:
the
sefd fits vs za with the fit residuals (.ps). (.pdf)
fits
using za and az terms (for comparison) (.pdf)
The lband wide receiver was replaced in feb03. All of the lbw calibration scans between mar03 and jun06 were used to fit curves to the SEFD. Frequency data was taken at: :(1175,1300,1375,1415) and (1415,1550,1610,1666). sefd curves were then computed fitting for sefd as a function of za (fits using azimuth terms did not improve the fit enough to make a difference). The fitting function (with za in degrees) is:
g(za)=c0 +c1*za + c2*(za14)^2 +c3*(za14)^3where the ^2 and ^3 terms are only applied for za ge 14 degrees.
The plots show the sefd fits vs za with the fit residuals (.ps). (.pdf) :
freq  # of points  fit rms
Jy 





















1415 Mhz has twice the measurements for the fits since it was included in both frequency groups. The sefd decreases from 1175 to 1415 Mhz and then remains relatively constant. Most of this is probably coming from Tsys decreasing as we move to higher frequency.
Note: The fits using za and az terms (.pdf) are available for comparison. They are not the curves being used.