On 8/18/2011 5:49 PM, Dave Platt wrote:

I've seen similar 4-vertical arrays on the roofs of some police cars
in my area. I infer that they're used to track down cars which have
had their Lojack locators triggered, after a car theft.


You are correct with respect to LoJack, which radiates in the high VHF
band. They do pseudo-doppler direction finding. I don't know how
fashionable LoJack is these days... the sophisticated thieves know how
to jam it. The widespread deployment of in-car GPS/cell (On-Star, etc)
covers a lot of the other cases. Face it, most car thieves aren't all
that smart.