[time-nuts] Speaking of Costas loops

[Dennis Ferguson]

On 5 Jul, 2013, at 09:18 , Jim Lux <jimlux at earthlink.net> wrote:
> I believe that the original WAAS repurposed transponders intended for other L-band satellite signals (e.g. Sirius/XM/LightSquared).

I'm not sure.  The original WAAS satellites, I think these

    http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1996-070A
    http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1997-027A

indeed were commercial L-band satellites, as you suggest, but they still
note that

   Each INMARSAT-3 also carried a navigation transponder designed to
   enhance the accuracy, availability and integrity of the GPS and
   Glonass satellite navigation systems.

which leaves the impression that particular bit of hardware might be
special-purpose.

Dennis Ferguson