Return to KLUBNL.PL main page

[Top] [All Lists]

LF: RE: Doppler effect.

To: [email protected]
Subject: LF: RE: Doppler effect.
From: "Andrew Talbot" <[email protected]>
Date: 26 Sep 2001 08:22:49 +0100
Reply-to: [email protected]
Sender: <[email protected]>
The rate of recombination of the E (?) layer causing the height to change at dusk / dawn will move at this sort of rate.  
I did see Doppler shifts, although not perhaps quite as great as this, on the signals from Larry at least once.  This is one of the mechanisms limiting the data rates we can go down to when using very low signalling rates.
A couple of years ago I made some tests receiving DCF, the German time signal, comparing its phase against a locally generated Caesium reference.  The interference patterns at dusk / dawn showed fading consistent with interference between the two skywave  & groundwave signals, one of which was changing at a rate consistent with this order of magnitude of velocity.
Andy  G4JNT
-----Original Message-----
From: Dave Pick [mailto:[email protected]]
Sent: 2001-09-25 18:40
To: LF Group
Subject: LF: Doppler effect.

Dear all.
I have the Argo screen-shots of ZL6QH recorded in Papua New Guinea, a path of about 4,700km. This is not very different from out trans-Atlantic tests but Ricks traces show a Doppler effect around midnight which spreads the signal over about 0.1Hz, I have never seen this on a 136k trans-Atlantic trace.
Have a look at the shots on and see what you think.
Rick has calculated that the reflecting medium would have to have a velocity of around 100m/sec, assuming a double hop, to cause this kind of shift.
Any propagation brains care to speculate on the cause of this, and is there a reason why we haven't seen it on 136? 

The Information contained in this E-Mail and any subsequent correspondence
is private and is intended solely for the intended recipient(s).
For those other than the recipient any disclosure, copying, distribution,
or any action taken or omitted to be taken in reliance on such information is
prohibited and may be unlawful.
<Prev in Thread] Current Thread [Next in Thread>
  • LF: RE: Doppler effect., Andrew Talbot <=