Intro

       Crosses were done using the 12meter xband receiver on 05-06may22 using 3C144(crab) and 3C461 (Cygnus A).
These crosses included  the cal diode so system temps were included.

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Setup

The setup was:

• 7 freq bands of 172.032 MHz each was used.
• cfr of bands:
• 8223. 8363. 8505. 8647. 8789. 8931. 9073.
• 142 MHz between band centers
• total span 1022 MHz
  
• A  10sec cal on,off was fired at the start of each cross.
• 2 sources:
• 3C144 (crab)  10 crosses,  flux=612 Jy (before  size correction)
  
• 3C461 (CasA) 5 crosses, flux=620 Jy
• pointing:
• az, el strips.
• 1.2 deg each. 120 secs/strip,10 hz sampling. bm fwhm=10amin
  
• .
• mock setup:
• 172.032 bw, 1024 channels , 166Khz/channel, 10Hz sampling
  
• pola,b recorded separately

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Processing the data

• idl was used for the processing.
• mascrossfind, mascrossinp, mascrossfit2d
  
• The resulting 2d gaussfit  parameters were used to give
• Tsrc/Tsys, Tsys (degK)
  
• az,el pointing error
• sefd
• fwhm of beam
  

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Plotting the results:

    The plots show the system performance results (.ps) (.pdf)

• Only the 8223 MHz band is plotted
• I'm using chris salters' fluxes. There is only  1 value for xband (not sure what freq it was done at).
  
• Each source is plotted in a different color
• Black: 3C144 .. crab
• Red   : 3C461 . . CasA
• System Performance pages:
• 4 frames
• top: Tsrc/Tsys shows Tsrc fraction of Tsys.
• 2nd: Tsys degK
• 3rd: SEFD  using size corrected flux
• bottom: beamWidth FWHM in arcminutes
• Page 1: system performance versus elevation.
• The 3C461 crosses were all done close to transit. there is not much variation in az,el.
  
• Page 2: system performance versus azimuth.
• Page 3: pointing error.
• Top 2 frames: a az,el pointing error vs az (in arcminutes)
• Bottom 2 frames: az el pointing error vs  elevation.

SUMMARY:

• Tsys  105 degK
• sefd
• 3800 Jy 3C144
• 4800 Jy  3C461
• Either the size correction is wrong  or source flux is not correct
• source sizes and uncorrected fluxes used:
  
• 3C144 - 6 Amin,  612Jy
  
• 3C461 - 5 Amin, 620Jy
• beamwidth 10Amin
• pointing error:

• azimuth		elevation
  mean Amin	rms Amin	mean Amin	rms Amin
  -.23	.44	-.07	.24