[time-nuts] Speaking of Costas loops

Bob Camp lists at rtty.us
Wed Jul 3 14:47:10 EDT 2013


Hi

The pipe in this case is up on one frequency and down on another. The conversion oscillator on satellite that's the weak link, no matter how good the signal from the ground happens to be. 

Bob

On Jul 3, 2013, at 1:48 PM, Attila Kinali <attila at kinali.ch> wrote:

> On Wed, 3 Jul 2013 08:29:02 -0400
> Bob Camp <lists at rtty.us> wrote:
> 
>> There are two batches of GPS / WAAS sats up there:
>> 
>> 1) The ones with numbers above 100 that are geosync and that only do WAAS
>> 
>> 2) The ones with numbers <= 32 that do nav. These are not geosync. 
>> 
>> I believe the only ones with corrected / high stab clocks on board are
>> those in the second group. The stuff in the first group aren't dedicated
>> sats, just leased transponders on conventional multipurpose geosync birds. 
> 
> I don't know about WAAS, but AFAIK the EGNOS signals are generated on
> ground using Cs references and retransmitted by the satelites using
> a "bend pipe". Ie. the signals should be of time-nut quality even without
> high accuracy frequency standards in the birds themselves.
> 
> (Sorry, i'm not able to find where i read about that, so no references today)
> 
> 			Attila Kinali
> 
> -- 
> The people on 4chan are like brilliant psychologists
> who also happen to be insane and gross.
> 		-- unknown
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



More information about the time-nuts mailing list