Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uwm.edu!rutgers!netnews.upenn.edu!eniac.seas.upenn.edu!depolo From: depolo@eniac.seas.upenn.edu (Jeff DePolo) Newsgroups: sci.electronics Subject: Re: Fooling Radar Detectors Message-ID: <28528@netnews.upenn.edu> Date: 15 Aug 90 22:12:59 GMT References: <1990Aug15.112532.17516@ariel.unm.edu> Sender: news@netnews.upenn.edu Reply-To: depolo@eniac.seas.upenn.edu (Jeff DePolo) Organization: University of Pennsylvania Lines: 25 In article <1990Aug15.112532.17516@ariel.unm.edu> ee5391aa@hydra.unm.edu (Duke McMullan n5gax) writes: > >Hmmm. Mark, I'd think it would backfire, since the radar will sense the >_largest_ doppler shift it finds. In any event, shielding the rest of the >car to have a significantly less bright reflection than the reflectors would >be a major nuisance. However, I don't _think_ there's anything unlawful about >it per. se. Most every radar gun will display the _strongest_ echo, not the one with the largest shift. This is after being filtered through a bandpass filter. Most radar guns will filter out post-mixing signals that would yield a reading of less than approximately 20 MPH and more than 99 or 199 MPH, depending on the model of radar gun. If it was the case that the gun would display the signal with the largest shift (i.e. the fastest car in the beam), target identification would be impossible if there was more than one car in the beam. Obviously the "strongest signal" method isn't foolproof either, but that's another story. --- Jeff -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jeff DePolo N3HBZ Twisted Pair: (215) 386-7199 depolo@eniac.seas.upenn.edu RF: 146.685- 442.70+ 144.455s (Philadelphia) University of Pennsylvania Carrier Pigeon: 420 S. 42nd St. Phila PA 19104