Intro

    Crosses on the moon were taken on 08apr16. The setup was:

• 2degree cross length, .01 deg/sec (xb fwhm=10.1amin, sb fwhm=39.9 amin)
• This was set to match the xband beam. The sband beam was bigger than the moon (30amin).
  
• mock spectrometer recorded the data: 172 mhz bw, 8192 channels, 1 second dumps, cfr: 2270, 8600.
• jpl horizons ephemeris to track the moon.
• 6 crosses in az,el were made.. from el=48 to el=40 deg.
• The moon was close to phase=0 (new moon).

Processing the data:

• The spectra were input and an rfi mask was made to exclude rfi (rms/chan, fit polynomial, and then clip)
• Total power was then computed for each second of data (using the rfi mask to exclude data).
  

Results:

    The plots show the results of the measurements (.ps) (.pdf)

• Page 1: total power strips
• top Frame: total power from the 6 strips are plotted vs sample: xband.
  
• black is the az strips, red is the el strips. The dashed green lines are the start of a cross
• the y axis is linear in power.
• 2nd Frame: total power strips for crosses for sband.
• Bottom: strips normalized to Tsys vs strip offset.
  
• For each strip an 1st order polynomial was fit to the edges of each strip (10% each side). This linear fit was then used to normalize each total power point to Tsys.
• Black, red: xb az,el strips
• green, blued: sb az,el strips
• the dashed yellow line is the center of the strip:
• The xb el strips have an increasing value as the move from low el to high el across the moon.
• Page 2: Moon deflection in units of Tsys.
• top: xband Moon deflection (in units of Tsys) plotted vs elevation.
  
• black is the az strip  values, red is the el strip values.
  
• For each az strip i fit a 2nd order polynomial and took the peak value as the center of the strip.
• This was within 1 sample of the center (.01 deg, .6amin).  so the ephemeris tracking was working pretty well.
• Since the el strips had a ramp, i used the 10 points about the center for the average el value.
• The green line is the average of the az,el values (in units of Tsys)
• middle: sband moon deflection (in units of Tsys) vs el.
• Bottom frame: Tsys computed from measured parameters:
• I got the aperture efficiency and expected tsys from : "The auscope geodetic VLBI ARRAY", j.e.lovel, journal of geodesy, feb 2013. They have similar patriot 12m telescopes, with the same receiver setup.
• The moon temp was take from: "Observing the moon at microwave freq using a large diameter deep space network antenna", david d  morabito, ieee transactions on ant and propagation: vol 56, no3, mar2008.
• The phase of the moon was close to 0 (it doesn't make much difference for sb or xband.

• 	xband	sband	Notes
  moonBrightness Temp	237 K	227K
  12m aperture efficiency	.63	.59
  bmDilution	1	.36	thMoon^2/ (thMoon^2+thBm^2)
  Tsys	123 K	107K
  Expected Tsys	90K	85K	from auScope computation. assuming Tsky+Tatm=10K