[time-nuts] synchronization for telescopes

[Chris Albertson]

The last idea was to use commercial broadcast transmitters.  No license
required.

Possibly all of the stations within some band.   It turns out that if their
frequency is drifting or if they have phase noise does not matter as long
as all the telescopes can "hear" the same set of transmitters.    So each
telescope records about 100 MHz of RF bandwidth and uses this as a "time
code" track.  All you need to "sync" multiple locations is a fast broadband
RF front end, A/D chip and a hard drive. Post processing involves quite a
lot of number crunching but computing is cheap and it need not be done in
real time.

That said, GPS might be cheaper because they are mass produced on single
chips but you don't need GPS if you have any strong transmitter(S) that all
telescopes can "hear"




On Thu, May 5, 2016 at 2:18 AM, Heinz Breuer <hbreuer at debitel.net> wrote:

> Hello,
> sorry I am late.
> As I understood a transmitter was not considered as there is no ham
> licence. I don't know in which country this will be used.


-- 

Chris Albertson
Redondo Beach, California