[time-nuts] Do ordinary clouds adversely affect GPS reception?

[Tim Shoppa]

I don't think clouds is the direct cause, but of course clouds in the sky
can be correlated with wet foliage.

Especially if the GPS Field Of View has a lot of angle taken up by tree
canopy, wet foliage can substantially degrade not just GPS reception but
other VHF and UHF signals.

I notice this the most in the fall when the leaves are large and mature and
are start losing their waxy coat, but have not yet fallen.

Even after all the leaves have fallen, wet branches have attenuation
ability as well.

Some research papers have connected windy conditions with UHF attenuation
especially deep fading as well (https://ieeexplore.ieee.org/document/1337081
).

Tim N3QE

On Tue, Oct 22, 2019 at 2:01 AM Dana Whitlow <k8yumdoober at gmail.com> wrote:

> A friend of mine living in SE lower Michigan recently bought
> a Geppetto GPS clock, and swears that it tends to lose
> satellite lock on cloudy days but does OK on sunny days.
>
> He is admittedly using a very poorly-sited antenna,
> placed in a window because his house has aluminum
> siding.  He reports that his Garmin handheld GPS
> has much less trouble acquiring and maintaining lock
> on cloudy days than does the Geppetto, but still tends
> to show higher levels of probable position error on
> cloudy days.  I don't yet know if he takes the Garmin
> outside for these comparisons.
>
> Is this a real phenomenon, or is my friend just imagining
> things?
>
> Meanwhile I think I have finally persuaded him to install
> the antenna outside on the roof.
>
> Dana    (K8YUM)
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>