With the GPS constellation's orbits inclined at 55 degrees from the equator
those of us in the northern hemisphere will find the satellites generally
toward the southern sky. This is much more significant in northern Europe
(London 51 29' N, Paris 48 49' N, for example) where the satellites are
near (or below) the southern horizon most of the time. I suspect that
eastbound and westbound flights will get better reception than northbound
and southbound flights if the antenna is within the panel since both the
crew and the engine will tend to shadow the antenna.
Can anyone confirm or refute this hypothesis from in-flight experience?
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of William
Harrison
Sent: Tuesday, February 05, 2008 2:43 PM
Subject: Re: Europa-List: GPS antennae siting
<willie.harrison@tinyonline.co.uk>
Thanks, David and everyone. Presumably, as well as avoiding the
shielding effect of the crew, antenna height relative to the engine
and the metalwork in the panel itself would help comms with
satellites close to the horizon.
On our last French trip in October, (Paddy Clarke, Alasdair Milne,
myself) we all lost GPS signal at various times as well. In addition,
my "Old Faithful" 295 died peacefully (so peacefully that there was
only a frozen display with no explicit warning that it was
meaningless - charming).
Cheers
Willie
On 5 Feb 2008, at 21:57, David Joyce wrote:
> <davidjoyce@doctors.org.uk>
>
> Willie, It sounds from your replies that top of instrument panel
> gives OK
> results, but I wonder whether the fuselage top between your doors
> may give
> even better results, as I can imagine that pilot and passenger will
> blank
> some satellites for a panel aerial in some situations. Everyone I
> have flown
> with on the trips I have done in Italy have lost GPS signal at
> some point,
> but I never did. I had tended to put this down to superior
> performance of my
> Garmin 295 as opposed to most people's Skymaps, but it may be
> because I have
> my aerial above head level. The cable supplied by Garmin and by Blue
> Mountain is plenty long enough to reach there, and otherwise gets
> coiled up
> behind the panel where it could possibly be subject to electronic
> interference. Regards, David
>
>
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