Devices Used for Tracking a Moving Vehicle Without Using GPSby Dan Seitz
Car theft is one of the most common property crimes in America. Losing your car can be emotionally difficult and financially draining, and some car location systems, especially GPS-based systems, are easily anticipated by thieves. Fortunately, there are several systems available that will track down a car without using GPS signals. With a little forethought, you can secure your car against theft and catch criminals before they can cause any damage to your vehicle.
A very common and simple method, used in the '50s and '60s and still in use today, is the radio receiver. A transmitter is hooked up to the car, and when the thief drives away, a receiver is used to pick up the transmitter's signal. The main drawback of this method is that it will only tell you the direction that the signal is coming from, and will not provide a specific location. This method will also require that the transmitter have a power source of some sort, either by means of a separate battery or direct wiring into the car.
Radio Frequency Identification
Radio Frequency Identification, or RFID, is a more refined example of the radio receiver. Objects can be "tagged" with a RFID chip that will transmit a signal, which a reader can pick up with an antenna and "interrogator", or RFID reader. RFID is useful because the tags can be hidden anywhere on the vehicle and can positively identify a vehicle even after it has been modified. They can also store information about the car, and have their own power source. However, the range of RFID tags is shorter than that of a standard radio transmitter, effectively only a few blocks with a good antenna.
A simple and effective way to track a car is by using a prepaid cellphone. If the phone is hidden in the car (and silenced), you can simply call it and effectively broadcast your car's position. The signal can be triangulated using widely available commercial software between two cell phone towers and the car will be located. This is the same method used by police over the years to track cell phone calls. However, the car's phone will need to be wired to some form of power source. This method may have difficulty providing precise information on quickly moving vehicles to the user, but will give direction and general vicinity.