On 03/14/2011 12:06 AM, J. Forster wrote:
I don't know what portion of all the GPS receivers deployed by the DoD now have direct-P(Y)-acquisition capability.
If they would be forced to shift in direct-P(Y) earlier if LightSquared caused them trouble, then it would hurt a bit, but I would expect it to be acceleration of a shift-program they need to do anyway.
Fundamental to direct-P(Y) acquisition is a priori clock synchronization. If too much time has elapsed since a receiver had a GPS satellite in view, then the receiver's local clock may have drifted so far that the receiver would need an unacceptably long time to search far enough in epoch-offset to find a P(Y) signal. Therefore, a direct-P(Y) receiver may need to be synchronized by external or extraordinary means, such as a portable atomic clock or a cable or radio link to an atomic clock. Nowadays, the military is so extensively networked (for a variety of reasons) that the requirement for external synchronization is not terribly burdensome.
Another already locked receiver would do just fine. Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
