lbw sefd curves after New lbw feed installed.

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*(za-14)^2 +c3*(za-14)^3

The plots show  the sefd fits vs za with the fit residuals (.ps). (.pdf) :

• Fig 1 shows the az ,za distribution for the data. The top plot is the az, za positions for the frequency group (1175,1300,1375,1415) while the bottom plot has the positions for the (1415,1550,1610,1666) group.
• Fig 2-3 are the individual fits for each frequency. The data is in black, the red lines are the fits. The fit values are listed on each plot. The rms of the fit is listed at: (sigma(y-yfit)) for each plot.
• Fig 4-5 are the fit residuals in Jy for each frequency.
• Fig 6: The 1415 Mhz fit residuals by source are plotted (in declination order). Each color is a separate source. This is to see if there are any sources with offsets (maybe caused by an incorrect flux).

      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.

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