Richard Clark wrote in
:

On Sat, 25 Mar 2006 01:53:24 GMT, "W. Watson"
wrote:

Ultimately, I'm trying to comprehend, via a proof, that two receivers
separated by a distance D can act as though they are a single receiver
of size D. Perhaps it can be done by simply considering the Young
double slit experiment. It bothers me that the idea is passed along
without ever proving it. Maybe the proof is trivial.

Hi Wayne,

The two receivers/antennas is called "synthetic aperture." You can
observe the same thing with one antenna that is moving, we commonly
call it "picket fencing." This effect is due to reflections and
direct signals interfering constructively and destructively as you
move through the interference field. The math for that alone is found
in "Fresnel loss."

The Young double slit IS the proof in that it contains all the math
you need. It contains two transcendental operations (sin or cos) as
many thetas as there are phases and distances, some magnitude
information, and the result pops out at you.

In fact, the math is all the same for all of these effects.

It gets a bit interesting to implement, though, if the antennas are 2000
miles apart!

--
Dave Oldridge+
ICQ 1800667