rf transmission

hey guys..need help here..
im in final yr of my engg n have to do a project..in a month..m actually stuck..big time..

the point is-to be able to detect location of a mobile when it passes thru an rf reader..this can also be done if i use Local Positioning System..but i dunno much in detail about both of them..as to how i can start with..if u cud suggest even ne sources..like sites or books..it will be a big help..

if i cud detect the position of a mobile when it passes a certain checkpoint..this is a very loose definition but thats all i cud think of as any idea..for final yr..project!!..

please can u help in suggesting me anything about it..

Thanks a ton..
Screw_driver

Put a "blind gps" in the vehicle. Use a radio link to telemeter the gps NEMA sentences to a base station. The base station will know instantaneous position, direction, velocity, speed. Go to this web site. Here you can see me doing this from my airplane. Ham radio operators collect the positional radio packets, and forward them via the internet to the data base being maintained in Finland. You can get a ham license and do the same, or create a local network using a license-free radio.