In message: <[EMAIL PROTECTED]> Steve Allen <[EMAIL PROTECTED]> writes: : In my understanding the GPS system : itself handles leap seconds pretty well, almost optimally.
One could say that GPS handles them perfectly, in that they do not exist at all in the GPS time scale. However, GPS' propigation of the GPS UTC offset leaves much to be desired. That data is sent in the alminac, which takes at least 20 minutes to down when a reciever is started "cold"[*]. Although you know the GPS time to within a few tens of nanos as soon as you have 4 satellites, you have to wait another 20 minutes after that to know UTC time if you are coming up cold. One can debate the meaning of 'almost optimally' til the cows come home, but my views lean away from such a characterization... Warner [*] The definition of cold varies from receiver to receiver, but all of them necessarily have a cold state (turn it off for a year, and it is guaranteed to be cold in that it can't possibly know the leap second values).