The typical Doppler at end-of-life of a GEO satellite is about 40 meters
per second. That translates to about .02 Hz at 136 kHz. I don't know
what can be expected at midlife, perhaps an order of magnitude better,
but that's still too much error for a serious phase measurement.
73,
Stewart KK7KA
----- Original Message -----
From: "Alberto di Bene" <[email protected]>
To: <[email protected]>
Sent: Tuesday, April 16, 2002 11:01 AM
Subject: Re: LF: Phase meter for propagation experiment
Stewart Bryant wrote:
> [...]
> Thus the phase measurements must be made wrt an analogue
> TV transmission.
> [...]
What about analogue TV via Astra satellite ? There are dozens of
analogue channels on this bird, and I am told some of them have
very precise synch pulses.
Would the relaying through satellite spoil their precision ? The satellites,
while geostationary, are not exactly at a relative rest wrt the earth.
They are wandering back and forth, with the small onboard jets correcting
this movement. I don't have enough info on the rate of change of their
speed to be able to evaluate the amount of the Doppler effect.
73 Alberto I2PHD
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