antenna diversity?

The diversity algorithm used by your radios has a big effect.

They're about equal. The main problem that both of these are really good at eliminating is frequency selective fading. This is where you have two paths to a given single antenna. The two paths are exactly

However, there's no way to optimize either the location (spatial) or the polarization of the two signals. The probability that they might cancel at any given point is fairly independent of the antenna construction and configuration. As long as there is more than one path to a given antenna, there will be nulls and cancellation. It really depends more on the room under test. I suppose I could contrive an artificially weird room that is polarization or location sensitive, but that's not reality. For example, if you're shooting over water, spatial would definitely be better because there's only one place for the signal to bounce and it's going to be the same polarization as the original.

Hmmm, what about being in a marina amongst both power and sailboats?

The (near) vertical sheets and vertical masts will do a marvelous job of generating vertical polarized reflections while somewhat blocking horizontal reflections. The relatively wide masts will reflect some horizontally polarized signals (because they're about a wavelength across), but not as much as the verticals.

I would guess(tm) that spacial diversity with the antennas vertically polarized would be best on the assumption that most of the usable signals will be vertical. However, there will be fewer reflections in the horizontal so maybe the horizontal is better. Argh... decisions.

One thing for sure, there's no need to do polarization diversity. There will be far more usable signal with vertical polarization than with horizontal. Maybe if you put the two antennas at opposing 45 degree angles? That might be useful. Argh... decisions.

Can I give up while I'm still sane?

Wait, you're arguing you're sane now?

Then how about putting up one at a 45 degree angle?

I'll go with the spatially diverse one instead of the one with polarization then.

Thanks,

-Bill Kearney