The idea that Qz (time on the quartz clock, no?) drops out in the subtraction seems to me to require Qz to be invariant.
Hi Bill, You might be making this more complicated intended. Antonio was asking about *resynchronizing* clocks. Here's another example. You're at home at 7:45 AM and see that your wristwatch is 7 minutes ahead of your kitchen clock. You get to work at 8:30 AM and notice that your wristwatch is 5 minutes ahead of your office clock. What conclusions can you reasonably make from this? Unless your wristwatch is really sick, the simple conclusion is that your home and work clocks differ by 2 minutes. You have used your wristwatch for time transfer. But now here's the good part. Notice that it doesn't matter what time you actually left home or what time you got to work. It also doesn't matter if your wristwatch is ahead or behind or spot on. Your wristwatch does not have to be accurate; yet it was still usable for remote clock comparison. Notice also that you did not have to synchronize your wristwatch at home or resynchronize it at work. All you needed was two measurements; the 2 minute conclusion is the difference of two time differences. So that's the point I was making. The actual time displayed by the portable clock drops out of the calculation. You get a nice time interval measurement without having to worry about time. This is the beauty of differences of differences. It's why ADEV is immune from phase or frequency offsets, etc. So remote clock comparison using a portable clock works even if none of the three clocks is accurate. Note the accuracy of the measurement (think error bars) is a function of their stability; in this example, the TDEV at tau 45 minutes. /tvb _______________________________________________ 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.
