[time-nuts] GPS PPS smoothing article

[SAIDJACK at aol.com]

I see other problems in the paper as well, for example why did they just  
plot a time-domain plot of before and after which doesn't really say much. It 
 "looks" less noisy, but that doesn't mean anything. The peak to peak is 
very  similar.

Instead they should have put that data into the freeware plotter, or  
Stable-32 etc, and shown ADEV plots that can actually discern between  before and 
after.
 
Also, as Matt mentioned if they do only have two dis-similar scopes, then  
they could have swapped the scopes, and do an interpolation between the two  
datasets.
 
Or they could have used the "trigger" input in the 500MHz scope (it has one 
 for sure) for the reference, and channels 1 and 2 for the before/after  
sources.
 
bye,
Said
 
 
In a message dated 4/11/2010 12:36:50 Pacific Daylight Time,  
magnus at rubidium.dyndns.org writes:

Matt  Ettus wrote:
> Interesting work.  They measured the "before" and  "after" signals with
> 2 very different oscilloscopes one with 100 MHz  BW and one with 500
> MHz, which they shouldn't trust..  I guess  they only had 2 2-channel
> scopes in their lab.

Their methods  did leave something to desire, but I thought it might be 
interesting  approach never the less and could maybe be inspiring or at 
least give a  different angle to things. I have been unable to figure out 
what the  frequency is for the XO and what single-shot resolution the 
detector and  the generator. But then, I did not spend quality time over  
it.

Cheers,
Magnus