Path: utzoo!utgpu!attcan!uunet!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: sci.electronics
Subject: Re: Police-radar countermeasures (and rockets)
Summary: A joke, right?
Message-ID: <3331@kitty.UUCP>
Date: 12 Aug 89 01:26:35 GMT
References: <661.24E1D0E5@bigtime.fidonet.org>
Organization: Recognition Research Corp., Clarence, NY
Lines: 30

In article <661.24E1D0E5@bigtime.fidonet.org>, hugo@bigtime.fidonet.org (Hugo) writes:
>   Of such interest is the newest addition to the home ECM scene, the
> aircraft detector.  It is essentially the same as the radar detector in
> that it is an alert device, but it operates by monitoring the police
> aircraft communication freqs and with some minor discriminator circuitry
> is able to determine approximate distance and course.  The latter must, of
> course, be relatively crude.  It then 'assesses' whether the aircraft
> poses a threat to your speed jaunt.  It shouldn't take long before the
> police alter the frequencies or go silent, but it is interesting the
> amount of money people will pay to drive fast.

	I trust that you intend the above to be a joke.

	For those readers to whom this is not obvious, virtually all local
law enforcement agencies communicate on their regular assigned land mobile
frequencies when engaged in aircraft operations.  There are no assigned
"police aircraft communication" frequencies in the VHF aircraft band. 
Wulfsberg Electronics and Motorola C&E, among other vendors, manufacture
synthesized radios for VHF and UHF land mobile frequencies having ARINC
mountings which are specifically intended for aircraft installation.

	Short of placing an Adcock antenna array or an equivalent device on
the roof of a vehicle, there is no way to ascertain "course" of an aircraft
based upon a radio emission.  For the application at hand, there is no
way whatsoever to ascertain "distance" of an aircraft.

<>  Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp.
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