Dear Stewart, LF Group,
I think this is a very interesting propagation experiment, apart from
potentially being able to enhance reception, so really ought to be tried. As
you say, there has been speculation about LF "beam-forming" on and off for
ages - I'm a bit sceptical about the extent to which the ionosphere will be
prepared to co-operate, but it would certainly be interesting to find out
the kind of separation between antennas that could be used for coherently
processing the signals.
I guess for an initial feasibility study it would only be necessary for a
number of stations to simultaneously make recordings under defined
conditions, and then the data could be up-loaded and post-processed at
leisure. I have a few queries:
-I presume you would have to initially synchronise the recordings to within
a GRI period for the signals to be combined in this way - would this require
some external timing signal, or is it possible to obtain that info from the
Loran signals?
-how would you compensate for variations in gain between different receiving
stations?
-how would you deal with variations of phase response within the passbands
of different stations?
As to whether I would run it at my station, certainly. I guess a broadband,
"always on" internet connection would be a requirement, which at the moment
I don't have, but may well get soon.
Cheers, Jim Moritz
73 de M0BMU
-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org
[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Stewart Nelson
Sent: 24 May 2005 09:54
To: rsgb_lf_group@blacksheep.org
Subject: LF: reception with multiple antennas
Hi all,
I've been dreaming about a system tentatively named MARS (Multi
Antenna Reception System)....
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