Newsgroups: sci.electronics Path: utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: Radar Theory Message-ID: <1990Jan15.164544.29488@utzoo.uucp> Organization: U of Toronto Zoology References: <1990Jan12.042446.8799@waikato.ac.nz> Date: Mon, 15 Jan 90 16:45:44 GMT In article <1990Jan12.042446.8799@waikato.ac.nz> spt@waikato.ac.nz (Simon Travaglia) writes: >What's to stop you syncing in with the Speed Detector and sending >back info to say that you are doing 500mph? >... And when you get stopped in your 1963 1.3l ford for pulling >540mph, you need simply say "Yeah sure..." > "...take me to court" And he'll say "That sure is an interesting-looking gadget on your dashboard there..." "...You're under arrest. You have the right to remain silent..." Quite apart from the small matter of you not being licensed to transmit in the police-radar bands, both the police and the courts would probably consider this "obstructing a police officer in the performance of his duties". Which is a far more serious crime than speeding. "Serious" as in "jail sentence and criminal record". Legal aspects aside, there's nothing hard about sending back a false signal that overpowers the real one (the radar probably locks onto the strongest signal, and reflections are fairly weak), although you'd have to be careful to stay within the limits of the radar unit. A signal saying "500 mph" is probably beyond what the radar's electronics are willing to consider as plausible, and possibly beyond what they can receive at all. That is, it might just light up its "something's wrong" light, or it might ignore your signal altogether and go for the next strongest one. -- 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