GPS and Tracking

Global Positioning System (GPS) is now a well established, low-cost technology with a wide range of applications. A GPS product contains a receiver that is able to provide accurate timing and location information from data broadcast by a network of satellites. The satellites continuously transmit details of their precise location and time. By using data from four satellites a GPS receiver can determine its own precise location and the exact time. GPS tracking systems can be developed by incorporating a GPS receiver with some form of wireless link to relay the timing and location information back to the end user. With the advent of assisted GPS, such tracking systems can now be designed to operate within buildings for applications such as asset tracking. As well as providing design services for clients seeking to develop GPS enabled products and systems, we can also assist clients seeking to develop products based around Galileo, the European global navigation satellite system.

Plextek has experience of designing both GPS based tracking systems and custom tracking systems based around alternative technologies. A good example of a custom tracking system development is the work undertaken for TRACKER Networks. TRACKER operates a stolen vehicle recovery system that allows any of the UK's 52 police forces to locate suitably equipped stolen vehicles. Plextek designed the vehicular unit for this telematics system, which is hidden discreetly in one of several dozen places around the vehicle, and parts of the infrastructure equipment including the base station mounted uplink receivers. The system uses VHF radio to communicate between the vehicle and a base site (and so TRACKER HQ) and allows tracking and location of stolen vehicles by the police. Several variants of the in-car unit have been developed by Plextek but all include a tracking capability. A photograph of the system in action is shown to the right.

The system operates by TRACKER HQ receiving notification that a vehicle has been stolen. For vehicles fitted with motion detectors this is done automatically by the in-car unit as soon as illegal movement is detected. Following confirmation of theft with the owner, the vehicle unit can be activated to repeatedly transmit its ID. Police cars and helicopters fitted with tracking equipment can then decode the identity of a stolen vehicle when it is in proximity. The police tracking equipment is a 4 antenna receiver, which uses time of arrival information from the different antennas to determine the bearing of the stolen vehicle and then track and locate it.

Variants of the equipment that interface with GPS modules have also been developed by Plextek. In this case the stolen vehicle also transmits its precise location (as determined by the GPS receiver) along with its ID. For more information about the TRACKER stolen vehicle recovery system click here.

Plextek also has experience of incorporating GPS into other product designs, such as the gaming console shown to the right. In addition to incorporating assisted GPS it features three dimensional gaming, SMS text messaging, MP3 music, MPEG4 video playback, a digital camera and Bluetooth (to allow multi-player gaming). The GPS data can be used for a range of applications including mapping, location based gaming and providing information on the location of desired local services such as banks or restaurants.

Shown to the right is a Plextek designed GPS receiver based on the latest SiRFstar III IC, from SiRF. The PCB measures just 23mm x 26mm and has the antenna mounted on the reverse side. This is a Plextek owned design and is available for license by third parties.

Our development lab is equipped with the latest instrumentation, such as a Spirent 12 channel GPS simulator, required to allow the development of GPS enabled products. We are also able to develop automated test equipment (ATE) to allow production test of GPS products.

If you would like to discuss the development of GPS enabled products or other possible solutions to your tracking and location system needs please contact us