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

[Magnus Danielson]

On 07/09/2013 04:25 AM, Joseph Gwinn wrote:
> Yes, of course, but I don't think I explained very well.  The issue was
> more economic than technical.
>
> There isn't much spare space, weight, or power in the birds, technology
> moves rapidly, and the satellite companies don't want to have expensive
> satellites that no longer generate rental income because something
> became obsolete.  So they ruthlessly simplify.  A bent pipe will handle
> any possible band-limited modulation, no matter if currently known or
> not, and so is the safest solution.
>
> Now WAAS may have become important enough to command dedicated
> hardware, but that came later, to the degree it came at all.

A bent pipe is more generic, but there are limits to how much you can 
alter the output frequency too.

If the payload is long-term contracted already when the bird is in the 
planning stage, then it is another issue.

Cheers,
Magnus