[DSP-10] Sun Noise Measurement

[Courtney Duncan]

Hi Bob and Mike,

Yes, I plan to use this method next try.  Also, several have suggested that I should get the coldest visible place on the sky to work from, something which I hadn’t been careful enough about before.

I used the Alt-F data in my 10,000 second EME2 analysis for my 2006 AMSAT Symposium paper so I’m pretty familiar with the EME2 version anyway.  I may have reverse engineered it at the time.

I’ll look around and see if I can find that MUD paper.

Thanks for the help,

73, Courtney, N5BF



> On Oct 15, 2016, at 10:47 AM, Bob Larkin <boblark at proaxis.com> wrote:
> 
> 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
> 
> 
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