[time-nuts] WWV Doppler Shift
Donald E. Pauly
trojancowboy at gmail.com
Tue Nov 20 02:33:10 UTC 2018
HF propagation of WWV or WWVH is horrible compared to VLF propagation
of WWVB at 60 kc. In this video the 5 mc WWV signal from Ft Collins,
Colorado is being received in New Jersey. It was compared against a
stable 5mc crystal source. You can see a shift of a few cycles per
second over a few seconds. This is due to the movement up or down of
the ionosphere at a substantial fraction of the speed of sound. I
understand that it can be as bad as a part per million short term at
some frequencies. The 10 mc and 15 mc broadcasts may be better or
worse at various times of day.
I have spent many hours watching WWVB in the days when they had the
old format. It was good to a part per billion except just before
sunrise and just after sunset. Then it degraded to either + or -5
parts per billion for about 30 minutes.
https://www.youtube.com/watch?v=nf9KWfS9QBs
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