Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Bad News- Lasers replace Radar guns
Message-ID: <1990Jan18.163107.15487@utzoo.uucp>
Organization: U of Toronto Zoology
References: <7263@lindy.Stanford.EDU> <349@egrunix.UUCP> <MIKEMC.90Jan17132215@mustang.ncr-fc.FtCollins.NCR.com>
Date: Thu, 18 Jan 90 16:31:07 GMT

In article <MIKEMC.90Jan17132215@mustang.ncr-fc.FtCollins.NCR.com> mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) writes:
>>   It can't be used while moving currently since it can't determine the police 
>>   cars speed yet.
>
>Why is that?  How do the current radar models work with respect to telling the
>speed of the officer's car?  Wouldn't it be similar?

No; remember the laser system is doing distance measurement, while the
radars are using Doppler velocity measurement.  The radars simply measure
the velocity of the background, which is always "in view" anyway because
their beams are so broad.  That doesn't work for the lasers.
-- 
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
