Links:
Intro:
21jan14: energy plots of 20Mhz code
11dec13: histograms, average bandpass of noise for different bandwidths.

radar datataking with pdev 

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  Intro:  (top)

   See radar datataking with pdev  for a description of how the datataking works.

• Mock radar sampling was tested using digital down conversion from 280 to 40 Mhz.
• 21jan14: 20 Mhz pncode was added to noise and then sampled at 20Mhz.
•  bandpasses, histograms, and energy plots were made
  
• 11dec13: noise was input at various bandwidths.
•  histograms and average bandpasses were made

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21jan14: 20 Mhz pncode.. energy plots.

• A 20 Mhz pncode was mixed up to 280 Mhz and then combined with noise at 280 Mhz
• A 20 db pad was put after the 260 amps to emulate protecting the a/d converters from the sb transmitter.
• 30 seconds of data was taken.
  
• histograms, average bandpasses, and energy plots were made.

The setup was:

• noise source -> 40 Mhz bw filter at 280 Mhz -> 260 Mhz amps ->20db pad -> reversed  Splitter-> scope -> mocks digI -> complex mixing  40Mhz to DC-> filter-> record.
• The reverse splitter also has a 64K, 20 Mhz pncode that had been mixed up to 280 Mhz placed at one of its input
• Levels:
• at scope: pncode=16 mVolts
• combined signal at scope: 49 mVolts
• a/d sigstat: .292
  
• The mocks were run at 160 Mhz clock, 4bit sampling, polA only

The first plots show the voltage histograms and average bandpass (.ps) (.pdf):

• The ripple in the average bandpass is probably coming from th 280 Mhz 40Mhz filter.

The 2nd plots show the energy plots (.ps) (.pdf)

• the data was decoded, the power computed for each code,and then averaged.
• The vertical scale is in sigmas.
  
• Top: all 64Klen of the code. 
• 2nd: blowup around the peak
• 3rd. Blowup around the 2nd strongest peak
• bottom: The phase of the peak was computed for each code and then plotted for the 250 + codes.
• The phase rms was .56 degrees.
  

processing: x101/140121/sbrdrtest.pro, doenergy.pro

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11dec13:noise input, histograms and average bandpasses.

• Mock radar sampling was tested using digital down conversion from 280 to 40 Mhz.
• Noise was sampled at various bandwidths.
  
• histograms of the sampled data and average bandpasses were made.
  

The setup was:

• noise source -> 40 Mhz bw filter at 280 Mhz -> 260 Mhz amps -> scope -> mocks digI -> complex mixing  40Mhz to DC-> filter-> record.
• The mocks were run at 160 Mhz clock, 4bit sampling, polA only
  
• For some of the later runs, a 20 db pad was placed after the 260 Amps to see how this would work for clipping the transmitter pulse.
  
• Different bandwidths, input rmsVolts, and mock shifts were tried.
  
• Histograms were made of each dataset as well as an average spectrum
  

The plots show the results (.ps) (.pdf):

• Each page has
  
• top: I,Q digitizer histogram
• bottom : average spectrum
• The table shows the bandwidths, shifts from each page:

• page	bw Mhz	shift	scopeV MilliV	rmsA/D counts	rmsProg counts
  1	40	14	214	.714	3.01
  2	40	14	200	.719	2.96
  3	40	15	100	.357	2.93
  4	32	15	97	.338	3.00
  5	20	14	154	.527	2.98
  6	20	15	75	.270	2.98
  7	10	14	109	.384	3.01
  8	5	13	148	.535	2.98

processing: x101/131211/sbrdrtest.pro