As I understand it, they're trying to get the WAAS sat back online and working properly after it went on walkabout some time ago. It's currently in a nonstandard orbit while they work on it. I suppose it's just pure speculation that they'd only be working on the WAAS service since the NOTAM doesn't say anything about it, but if that were the case there wouldn't be any effect to timing. -Jack Carrozzo On Fri, Jan 21, 2011 at 12:31 PM, Robert E. Seastrom <rs@seastrom.com>wrote:
It is unclear from this NOTAM whether this is an intentional perturbation of the satellite signals vs. a terrestrial transmitter (my money is on the latter), but it illustrates why one might want geographically dispersed time sources on one's network, as well as why the current trend towards decommissioning LORAN (and in the future, other navaids) in favor of reliance on a single source is a Bad Plan.
I'd be curious to see what effects (if any) those who use GPS-disciplined NTP references in Southeastern Georgia see from this experiment.
https://www.faasafety.gov/files/notices/2011/Jan/GPS_Flight_Advisory_CSFTL11...
-r