Path: utzoo!mnetor!uunet!husc6!uwvax!rutgers!ames!pioneer!eugene
From: eugene@pioneer.arpa (Eugene Miya N.)
Newsgroups: sci.misc
Subject: Re: Radar
Message-ID: <3775@ames.arpa>
Date: 29 Dec 87 01:20:57 GMT
References: <317@uhmanoa.UUCP> <19253@linus.UUCP> <16999@topaz.rutgers.edu> <1594@brahma.cs.hw.ac.uk> <2576@calmasd.GE.COM>
Sender: usenet@ames.arpa
Reply-To: eugene@pioneer.UUCP (Eugene Miya N.)
Organization: NASA Ames Research Center, Moffett Field, Calif.
Lines: 35

In article <2576@calmasd.GE.COM> jnp@calmasd.GE.COM (John Pantone) writes:
>Adrian Hurt:
>>Incidentally, how good is radar against non-metallic targets? How good are
>>infra-red missiles against piston-engined planes?
>
>Radar (at least the radar used by police to detect speeders) can detect
>non-metallic objects quite well.  I have had the opportunity to test them
>against a number of substances, and know the results to be true.  The best
>reflectors were (non-metallic):
>Fiberglass, plywood (especially marine), doped canvas (like airplanes) and
>solid hardwoods (oak and maple).  Soft wood was less reflective (like balsa)
>but was not at all invisible.

Ah! A terrible posting by one a member one of the companies who make
radar! Ah!  Radar depends on many things.  Get Skolnik's book
Introduction to Radar Systems (now 3rd ed.) if you want to learn more.
Basically, the radar equation is a O(distance^4) equation with terms for
the cross-section of an object, the dielectric constant, the wave-length
of the signal, etc. etc.  There are different radar for rain drops,
clouds, air defense, imaging, etc.

Then the article which posted this:
>to home in on. In a related story, I heard that the B1 bomber has
>1 / 1000 the radar signiture of a B52. It might be that the British

Not quite that good.  It depends on a lot of things like if the plane is
banking, climbing, etc.  IR also has other problems since it encompasses
much broader bandwidths than wide light.  It depends what IR ranges.

From the Rock of Ages Home for Retired Hackers:

--eugene miya, NASA Ames Research Center, eugene@ames-aurora.ARPA
  "You trust the `reply' command with all those different mailers out there?"
  "Send mail, avoid follow-ups.  If enough, I'll summarize."
  {uunet,hplabs,hao,ihnp4,decwrl,allegra,tektronix}!ames!aurora!eugene