sbn calibration after m8-4 cable repair

Intro

    The 13jan14 earthquake damaged cable m8-4. The repair was finished on 11mar14. X102 calibration runs were done 11 and 12mar14 to see how the pointing and gain were.

The setup

• a tilt sensor run was done prior to the calibration run to check the 1az tilt of the platform.
  
• The calibration runs used: the sbn receiver, the interim correlator, and the standard x102  heiles calibration scans.
• The tiedowns were tracking the average height of the platform during the runs.
• The weather was overcast 11mar14 and a light drizzle on the start of 12mar14

The data

• Page 1: az,za tracks across the dish.
• I limited the data to > za=2 degrees. The data below that had pretty bad pointing errors (because the model was never very good down there..).
• Page 2: pointing errors vs az,za
• top 2 plots: za error vs za,az
• bottom 2 plots: az errors vs za,az
• the mean offsets were :.17,-.52 in za,az
• the mean rms's were: 3.24, 4.91 asecs in az,za
• B0518+165 (3c138) seems to have lots of outliers.
• This was the first source taken on 12mar14.. when it was drizzling lightly...
• Page 3: arrow plot of pointing errors.
• The length of the arrow is proportional to the total pointing error (1 tick mark is 5 asecs).
• the direction of the arrow is the direction of the pointing error.
• Page 4: gain,Tsys,sefd, beamwidth
• the red boxes (B1442+101) and the purple boxes (B0824+294) look like they have fluxes that are a little low:
• the gain is low for these, the sefd is high, but tsys is the same as the others.
• Some of the beamwidth fits for B0518+165  (black +) seem to be off.
• Page 5: plot gain vs azimuth.
• This was to look at the difference between the southwest fill area (110-140) to see if it was lower.
• previous higher frequency receivers showed a dropoff  in this area. sbn does not show a large difference.
• Page 6: coma, sidelobeheight, beam efficiencies...

Summary:

• Pointing error: za: 3.24 asecs, az: 4.9 asecs: total error:   5.9 asecs
• sbn gain: about 10 K/Jy (out to za=15).
• The telescope scope is performing similar to before the earthquake.
• Not changes will be made in the pointing model.