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History:

• 13jan13: updated pointing offsets.
  
• 29sep08: installed new cal values. backdated to 18aug05.
  
• 10oct04: installed new cal values. backdated to 15aug04.
• 10sep04: new gain curve installed and back dated to be valid from 15may04.
• 14may04: cal diodes replaced.
• 14may04:  horn moved down in focus direction to put it in focus.
• 29apr04: horn moved x,y direction after feed survey (focus motion not yet done).
• 1999-14may2004  The measured system temperature drifted from 1999 thru 14may2004. This was caused by the cal diodes drifting. On 14may04 the diodes were replaced and the measured system temperature stabilized.

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Calibration measurements:

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Miscellaneous:

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May04 to Sep04  fit GAIN CURVES to calib data.  (top...)

    Gain curves were fit to the sband wide  calibration gain data using  15may04 through 01sep04.  The start of this epoch was after the cals were replaced and the horn had been lowered put it in focus.  The plots show the gain data (black) and the fits (red) for 2212, 2380, 2690, and 2850 Mhz. These gain equations were installed on 10sep04 and back data to be valid starting on 15may04.

• 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 printed 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 sbw gain for data after 15may04 from these
equations. The coefficients can be found in the ascii file  data/gain.datR7 (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.datR7.
Be careful using these routines for data before 15may04. There is not gain curve and the routine should return and
status reflecting that...

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may04 to sep04 : System performance of data used to compute gain curves.  (top...)

     Heiles calibration scans done from 15may04 (new cals, horn lowered) thru 01sep04 were used to measure the
system performance. This data was then used to compute the gain curves for use on data taken after 15may04.

    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. 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 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.

• Fig 1 2212Mhz Gain,Tsys . 260 points
• Fig 2 2212 Mhz sidelobes,beam efficiencies
• Fig 3 2380 Mhz Gain,Tsys 260 points.
• Fig 4 2380 Mhz sidelobes,beam efficiencies.
• Fig 5 2690 Mhz Gain,Tsys 151 points.
• Fig 6 2690 Mhz sidelobes,beam efficiencies
• Fig 7 2850 Mhz Gain,Tsys 259 points.
• Fig 8 2850 Mhz sidelobes,beam efficiencies

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