Re: ATM Atomic clock stuff...

["Jack Brindle" <jackb@ricochet.net>]

>I may be missing something here, but I think the signel from WWV travels
at
>186,000 miles per second. I don't think transmission delay would be a
factor in
>most applications. You do the math --from Colo. to your location.

Andy, of all peopol you should realize the error in what you said. The
signal doesn't travel in a straight line that distance, but rather it
bounces off the earth and ionosphere to get where it goes. This adds a lot
of distance (and time) to the signal. How much is hard to say, but it at
least doubles things.

Also, light and radio waves travel at 186,000 mps in a vacuum, but somewhat
less in all other media, including the earth's atmosphere. Not much less,
but it is a bit less, depending on the velocity factor of the media. Again,
it would be difficult to say what the velocity factor of the atmosphere is
at any given moment due to changing weather conditions along the path, etc.

Your whole point is well taken, though. There won't be very much delay in
the signal as it traverses its way to the receiver. The processing delay in
the receiver (filters, etc), will probably match the signal's propogation
delay.

I have to agree with Jeff on the need for absolute accuracy in this
particular application. Is it really necessary given all the other
variables and tolerances involved in astronomical observations?

Now, let's get back to the topic...


-Jack Brindle
ham radio: wa4fib
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"My name is bud lightbeer. I come in pieces!"