-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Lux
Sent: Thursday, September 16, 2004 12:16 AM
Subject: Re: [TowerTalk] verticals in woods vs. in a field
>In any case, if you want to attack the problem using FDTD, GTD, or any
other
>EM modeling technique, there's a whole lotta literature out there I
>particularly like the paper from Japan where they had this tree in a
pot
>that they measured at a variety of frequencies in an anechoic chamber
over >a
>period of 6 months or so, as the tree died. I don't think they intended
the
>tree to die, but it did, and they have this series of measurements with
>successively less foliage with the tree drying out. I picture in my
mind
>some egregiously underpaid grad students dragging this huge container
in >and
>out of the chamber every week because Doctor Professor somebody got the
>grant to study it.
Reminds me of a project I had back in the mid-70's at an aerospace
contractor: I had to measure the radar cross-section of various live and
dead bushes and trees, at various microwave frequencies, and attempt to
correlate that with their optical cross-section. You can probably
imagine why someone would want to do this.
We had a relatively large, auditorium-sized anechoic chamber to work in
- anechoic above 1 gig, at least - but it was also quite dead
acoustically, black absorber on all the surfaces, and very spooky to
work in. "If a dead tree falls in an anechoic chamber, and it makes no
sound, does it still have backscatter?"
Oh man, I had almost completely forgotten about that project, and all
the jokes made at our expense.
geo - n4ua
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