[DSP-10] Sun Noise Measurement

[Bob Larkin]

Hi Courtney,

Great to hear from you.  As for the measurements, what you are doing 
should be valid.  The number in the corner is the sum of the powers in 
the DFT bins, converted to dB after adding.

But, there is provision to do better.  In the FM mode (of all things) 
the s-meter reading is the average noise power in the 12 kHz bandwidth. 
In addition, the ALT-F3, ALT-F4 averaging also applies to this 
measurement, so you can adjust the averaging time from 0.6 sec on up. 
This is block averaging over the chosen time interval. Because of this 
"instrumentation" use, the s-meter changes to show the dBm power to 3 
decimal places.  This is generally excessive, but might be useful. See, 
also,
  http://www.proaxis.com/%7Ekd7ts/v396/1CH1.HTM#sun_noise

The ALT-F data record in FM is different, and has several data items 
useful for this kind of measurement.  I can't find where we wrote that 
data format down.  Am I missing it?

Finally, I did a paper at the 2003 Microwave Update on Sun-Quiet 
Sky-Earth  noise measurements that has some comments on noise pickup.  I 
will see if I can get permission to post it.  It tries to summarize the 
general art of such measurements, and also adds info on using the three 
measurements to estimate both receiver noise figure and antenna gain.  I 
think some of that relates to what you are doing.

73, Bob   W7PUA