[time-nuts] Speaking of Costas loops (WAAS)

[Bob Camp]

Hi

It could be 10 pounds of stuff and 340 pounds of shielding …

It also could be 10 pounds of WAAS and 340 pounds of something they don't want to talk about. 

Bob

On Jul 11, 2013, at 3:17 PM, David J Taylor <david-taylor at blueyonder.co.uk> wrote:

> If you look at the pictures here
> 
>   http://www.orbital.com/NewsInfo/Publications/Galaxy_Fact.pdf
> 
> the satellite on the right has things sticking out the bottom, in the
> back corner, that are missing on the others and that look a lot like
> the antennas on GPS satellites.  The WAAS satellite is also 350 pounds
> heavier than the other two even though the C-band payload is identical
> on all three, so it seems like there could be a fair amount of extra
> stuff added for WAAS support.
> 
> Dennis Ferguson
> _______________________________________________
> 
> Thanks, Dennis.  The antennas don't surprise me, as they would need to produce a near-whole-disk coverage at a similar ground received power level to the GPS satellites.  That extra weight /does/ sound a lot if it were "just" a simple transponder for earth produced information.  Here in Europe was have three EGNOS sources (all on other satellites, I believe), and I don't believe they play any part in actual position fixing, but they do provide extra information enabling the fix to be refined.
> 
> Cheers,
> David
> -- 
> SatSignal Software - Quality software written to your requirements
> Web: http://www.satsignal.eu
> Email: david-taylor at blueyonder.co.uk 
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