The idea of linking a low cost GPS receiver to the electronics from within a mobile 'phone is not new : a number of companies are developing security solutions along these lines. The cost of the GPS and mobile 'phone electronics are small - and getting less - since they are both mass-market products. The mobile 'phone companies may also subsidize the cost, since they get a long term return on the rental for the communications service.

Some companies offering these products have developed more sophisticated systems, which offer more facilities but are more expensive and restricted to specialist markets such as covert tracking of cars that the owners do not know are bugged.

GPSS can be used with all these systems - however simple or complex.

How Does It All Work ?

The GPS and mobile 'phone electronics is a small package that is hidden within the vehicle to be protected. The output from the GPS can also be made available on a socket, so that it can also support in-car navigation (or Chase - see later) if a computer is also installed in the car.

The solution also requires a PC computer running GPSS, and a modem connected to a normal telephone. This can be located anywhere, such as home or office. It need not even be in the same country !

If the car is stolen, and you want to know where it is, you simply use the telephone to dial up the number, and the GPS in the car then sends back GPS data every second - without those in the car knowing ! The data is displayed on maps by the GPSS software running in the PC computer in home or office.

And you can also 'Chase' from another vehicle

The receiving computer does not have to be fixed at home or office. It could be a Notebook PC connected to a mobile phone carried in another car. If that car also has a suitable GPS receiver, it could even use the 'Chase' facility within GPSS. This will show both cars on the map, and give voice guidance from the chase vehicle, to guide the driver within yards of the other stolen car.

This 'Chase' facility in GPSS was featured in the Television programme.

In 1996 we hosted the filming, by Topical Television, of the programme first broadcast on Wednesday 27th November '96 on Meridian Television. The programme, called 'Put It To The Test', was broadcast again on BBC1 at 3pm on Tuesday 21st January '97. It made interesting viewing and was filmed on local roads in Berkshire and Surrey. Police and businesses travelled to Sunninghill from some distance, to install and test equipment in time for the film crew, who spent most of the day filming. Thames Valley Police Constabulary took an active role in the day's trials and filming operation. For more pictures see the As On TV Page

The individuals and companies who participated in exercise were as follows:

• Thames Valley Police Constabulary. Inspector Reg Pengelly was interviewed in the studio. PCs Mick Claire and Matt Jones were the officers in the police Astra.
• Martin Dix of INTEC. Tel 01264 773888. Provision of the £80,000 Lexus Soarer, complete with its own computer navigation system, and expertise in the installation of a rugged PC computer loaded with the GPSS software.
• Richard Oliver of SAIC. Tel 01276 675511. Provided the rugged computer.
• Adrian Ellis of Rockwell. Tel 01344 486444. Provided the Soarer's Zodiac GPS.
• John Hemmingway of CMP. Tel 01908 218200. Provided Focus FM DGPS.
• Dave Sparvell of R.F.Technology. Tel 01276 686889. Provided the GPS-Radio pod used to track the Soarer from our base at 22 Armitage Court. This equipment is intended for low cost multiple vehicle tracking systems that can exploit existing voice radio channels. e.g. to insert a GPS-based position report automatically at the end of a voice transmission.
• Paul Hough (see Satellarm above). Provided the Stolen Vehicle Tracking System advertised in the December BBC Top Gear Magazine. This GPS-Cellphone device was hidden in the Soarer. It can be called from any telephone, including mobiles such as the one used in the Police car. The voice version responds with spoken latitude and longitude coordinates of the car. e.g. "5 2 2 3 point 8 2 North 0 0 0 3 9 point 6 0 West". These can be looked up on a suitable paper map, or simply typed into a PC running GPSS - which will then show the car on a map and describe the position relative to the nearest major towns. e.g. "25 miles west of London in Sunninghill". The data version passes the GPS data directly back to be fed into the PC - which could be a Notebook PC carried in a Chase vehicle such as a Police Car. A standard NMEA interface is provided to permit the GPS receiver in the device to be used for in-car navigation by connecting it to a Notebook PC running GPSS.
• Graham Chadwick and Sean Lawlor of Advanced Systems Solutions (A2S). Tel 01922 57380. A2S provided the 'next generation' car navigation computer known as the MCS-100. This compact unit, advertised in Top Gear magazine, is the size of a small TV monitor but includes: full VGA resolution TFT screen with touch system, 486 PC computer, GPS receiver and cellphone data interface. It is supplied already loaded with a free copy of GPSS. It was installed in the Vauxhall Astra Police vehicle, and GPSS was configured for 'chase mode' (see below). A conventional mobile phone in the Police car was used to dial in and receive GPS data from the Soarer. This data was picked up by a small microphone held near the handset, and passed into the MCS-100 with the Police cars own GPS data. The result was that both cars could be tracked, and voice guidance given to tell the Police driver the relative position of the Soarer. e.g. "(Stolen Car) destination 350 yards to our right at your 2 o'clock".

The following describes the GPSS Chase facility - which is now available in GPSS since Version 4.1 in December 96. Direction Finding based chase capability had been available for some time. Don't be misled - we are not encouraging GPSS users to start chasing each other around the countryside ! Police and Private Investigators may benifit from this new capability - designed to provide safe voice guidance from a following vehicle needing to know where another vehicle is. The other vehicle need not be a car, but anything on which the small pod of equipment is located. It might be on a hot air balloon, to enable the retrieve crew to find it easier when it is low hidden by trees, or has landed and deflated. I'm sure you can think of many other applications. For the technically minded, here is a simple explanation of the new facility. It works by ensuring that GPS receivers are chosen to ensure that the NMEA GPS sentences from the local GPS (in the car) and remote GPS (object being followed), are different. This enables a simple solution where both streams of data are passed to the computer on the same COM port. The GPSS software is configured for 'chase' mode, and told what NMEA sentences to use, and which to ignore, for both local and remote GPS. The result is the destination location is regularly updated from the incoming radio data, and the local GPS continues to tell the computer where 'we are' and where we are heading. It can therefore provide voice guidance to the moving (remote GPS) location.