lbw system performance after horn focus moved.


Links to plots:

system performance with all freq over plotted.
system performance plotted separately for each freq.

 The lband wide  horn was moved 3.67 inches in the focus direction on 21nov02 to place the phase center at the correct position.   All of the heiles calibration scans 21nov02 through 31dec02 for the lband wide (lbw)  receiver were used to plot the system performance. This includes dedicated calibration runs and individual calibration scans done by observers.  The data was taken at 1175, 1300, 1375, and 1415Mhz with about 150 points at each frequency using 9 sources .
    The first set of plots show the system performance with all frequencies over plotted. The sources are identified by symbol and the frequencies by color.

  • Fig 1 has the Gain in Kelvins/Jansky. This relies on the cals and the source flux. The  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 2 plots the coma parameter, first sidelobe height below the peak, the main beam efficiency, followed by the main beam + 1st sidelobe beam efficiency.
  • Fig 3 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 1175 Mhz Gain,Tsys.
  • Fig 2 11175 Mhz sidelobes,beam efficiencies
  • Fig 3 1300 Mhz Gain,Tsys.
  • Fig 4 1300 Mhz sidelobes,beam efficiencies.
  • Fig 5 1375 Mhz Gain,Tsys.
  • Fig 6 1375 Mhz sidelobes,beam efficiencies
  • Fig 7 1415 Mhz Gain,Tsys.
  • Fig 8 1415 Mhz sidelobes,beam efficiencies
  •     Use the second set of plots to identify the sources.
        Gain curves were also fit to this data.
    processing: x101/lb/dec02/