Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: radar countermeasures
Message-ID: <1988Mar7.233054.235@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1101@silver.bacs.indiana.edu> <2203@saturn.ucsc.edu>, <3606@killer.UUCP>
Date: Mon, 7 Mar 88 23:30:54 GMT

> > In my experience a good X band radar unit can get an accurate
> > speed fix EVEN WHILE MOVING  L O N G before the target's detector
> > goes off...
> 
> This is generally not true...

Radar signal return follows an inverse-fourth-power law, inverse-square
outbound and again inbound, assuming diffuse reflection.  Radar detection
is only inverse-square, since the signal doesn't make a round trip.  Other
things being equal (detection technology, size of antenna, etc.), this
means that a radar signal can always be detected from well beyond the
effective range of the radar itself.  Of course, other things aren't always
equal, and if the radar isn't in steady use, a range advantage may not mean
a time advantage.
-- 
Those who do not understand Unix are |  Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly.    | {allegra,ihnp4,decvax,utai}!utzoo!henry