[time-nuts] Mounting GPS Antenna on Steel Roof

[Bruce Griffiths]

Brooke Clarke wrote:
> Hi Matthew:
>
> Some antennas are receptive to signals coming up from below.
>
> Since the signal is circularly polarized the first reflection is supposed to be 
> down something like 20 dB, but the second reflection will be much stronger, so 
> you would also need to look at those.
>
> Have Fun,
>
> Brooke Clarke
>   
Brooke

Surely the response of antenna to a reflected circularly polarised wave 
depends on whether wave the is reflected from behind or in front of the 
antenna?
When viewed in the opposite direction to the wavefront propagation an 
RHCP wave looks like an LHCP wave.
Also imperfect reflectors tend to scatter the wave and only partly 
convert the polarisation direction.

Bruce