[time-nuts] ADEV

[Magnus Danielson]

On 11/13/2010 04:53 PM, jimlux wrote:
> Magnus Danielson wrote:
> One of the big meetings on this topic was in the
>> NASA Goddard space center, and the result of that is found in the NASA
>> Special Publication 80 (SP-80):
>> http://hdl.handle.net/2060/19660001092
>>
>> Un the part 1 "User's viewpoint and requirements"
>> First article in there is "Short-term stability for a doppler radar:
>> Requirements, Measurements and Techniques" by D.B. Leeson and G.F.
>> Johnsson.
>> Fifth article is "Satellite Range and Tracking Accuracy as a function
>> of Oscillator STability" by J.J. Caldwell Jr.
>> Sixth article is "Short-term Stability Requirements for Deep Space
>> Tracking and Communications systems" by R. L. Sydnor.
>>
>
>
> Thanks for this reference.. I had seen some of the papers before, but
> this collects them all handy in one place.
>
> The paper by Sydnor is quite handy, because it's basically the same way
> we do things still (well, we don't punch the Doppler estimate on paper
> tape, we've moved a tiny bit forward. And, most, but not all, of our
> equipment is calibrated in Hz as opposed to cps)..

When researching my contributions to the Allan variance Wikipedia 
article I found that many of the articles referred back to papers from 
that conference, so I dug around a little and came up with that 
reference. It is online from NASA if you just care to use their 
web-pages a little.

http://en.wikipedia.org/wiki/Allan_variance

I took some pride of providing significant contributions to the field as 
referenced articles, and also as far as possible provide linkage to them 
in online form, if possible to get for free. This was indeed one of the 
references I was quite happy to find. I have not read all the 300 pages, 
but there is a lot of good material in there. For instance, the DMTD 
technique has a precursor in the cross-correlation technique being 
presented on page 111 by R. F. C. Vessot, L. F. Mueller and J. Varnier 
in "A cross-correlation technique for mesuring the short-term properties 
of stable oscillators". They measure the beat frequencies of two 
H-masers 1,420 GHz as being mixed down to first 30 MHz and then 600 Hz.

Oh, and I still have a number of things to properly cover on the Allan 
variance article for sake of completeness. Progress have just been slow. 
Doing exercises like these is however very rewarding as one needs to 
learn the things on a deeper level.

Cheers,
Magnus