> It's interesting that the now in development carrier phase GPS time > transfer method that might offer 1,000 times lower uncertanity is based > on the Ashtech Z12 surveying receiver, not a timing specific GPS receiver.
These are Z12-T receivers, an expensive upgrade to the standard dual-frequency Ashtech Z12 receiver. They require a high-performance (typically cesium or H-maser) 20 MHz frequency as input. The 1PPS can be used directly, but usually one just collects pseudo range data from them and that data is post-processed (up to two weeks, I think) by various geodetic services with clock and orbit corrections. DougH can provide more info on this (now obsolete) receiver. I had a Z12T too but it died on me last year. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
