🚀 go-pugleaf

In article <1342@titan.camcon.uucp> mb@camcon.uucp (Mike Bell) writes:
>Aw hell!  Haven't you guys heard that F*rd have been working for years
>on the so-called `stealth car' for the DoD.  It features ultra-smooth
>body contours to reduce reflection and minimise drag, a low radar
>cross-section engine using specially-developed ceramics, glass fibre for
>the bodywork, glass for the windows, etc.  It is painted with this
>really special paint which not only absorbs radar electro-magnetic
>emissions, but also the visible spectrum as well.
>
>You can have it in any colour you like, so long as it's black:-)

Actually there is another color, Seafoam Green.  Black though is infinitely
preferrable.

In a more serious, if not more speculative, mind I have a question for
thought.  I am intrigued by passive means of countermeasure.  They are
or can be cheaper (chicken wire, flares, chaff, compost heaps, etc. etc.)
and more fun.  They are usually legal.  Ok, for those of you in the IEEE's
digital signal processing society (ASSP), the Jan. '88 issue of the ASSP
Magazine (not the Transactions) has a somewhat provocative article.  I am
referring to the Schroeder article.  Mr. Schroeder seems to be a quixotic
character, an APPLIED number theorist.  His article seems to be quite
interesting with perhaps some utility to the passive ECM arguement here.

Mr Schroeder builds "diffraction gratings" with depths and spacings derived
from results in number theory (powers of primitive roots to construct
reflection coefficients   pg.8).  The pattern attenuates the zeroeth
diffraction order (reduced "radial" return).  The energy is effectively
scattered everywhere except the direction from which it came.  Note, this
is my interpretation of the paper, and not necessarily what Mr. Schroeder
said.  Since effectively, no energy travels back to the detector, the man
does not see you.

I believe Corvettes and Fiero bodies are made from composite materials.
Are these invisible at X-band?  Are there others (no resonant dipoles
in polymer chains, etc.) suited to make car bodies!  If so, the inner
surface could be molded to an appropriate pattern (passive ECM-diffraction
grating) and painted with a reflective paint.  If my train of thought
is clear, the outer surface would be attractive (black or seafoam green)
and the inner surface would be interesting.

Ok, you groovy guys and gals.  Chew this idea up.  It came from reading
the article and the recent discussion on the net.  Why will it not work?
Why will it work?  If it can work, it is probably being worked on right
now.  The article implied as much.

In another vein, I was serious in my follow-up posting a few weeks ago
about an absorbing paint.  A couple of years ago a friend of mine saw
an article in the trade magazines (the same ones you guys saw all your
active devices) for a can of spray for your car.  It had all the usual
hype about how it beat everything that radiated.  The follow up was that
the person who ran the article wound up in court.  He had no product.
He got an incredible response from the article (a can was ~$17) and was
going to pay someone to invent the product.  Many of us chuckled about
the article.  All of us would have bought a case of the stuff if it was
legitimate.

So put on your thinking caps.  Can we beat 'em at their game?  Remember,
they started it (none of my friends have radar guns to check if they are
speeding)!

floyd@brl.arpa