A tracker works via GPS satellite navigation network (Global Positioning System) to obtain its position. The GPS network is made up of 24 satellites and their ground stations (plus 3 backup satellites in case one fails). Initially funded by the U.S. Department of Defence (DOD) GPS today has many civil uses as well as military.
The satellites transmit a low power signal and their orbit calculated so that a GPS receiver is always visible to at least 4 of these satellites. From the visible 4 satellite transmissions, the GPS Tracker calculates its location to within a few metres. The tracker is able to do this through a mathematical equation called trilateration. This is the same system used in mobile phones and car navigation and is extremely accurate.
Passive and Active Trackers
There are two types of tracker, a passive tracker that records the information on its location to be downloaded when “docked” at a later time and the more popular active GPS that reports back its location via GPRS or 3G to the web server providing real-time information on its location. The web server can report positions every 10 seconds depending on the reporting time span the tracker is set too. The web server via a user interface reports the position on a moving map display.
A tracking system is made up of the following components:
- GPS tracking device – Used for transmitting location from the vehicle and can be set to record other factors such as speed.
- Web server – This receives the information transmitted via satellite or GSM from the vehicle.
- User Interface -This is where the information becomes viewable and interactive.
Software on the web server stores records of the movement of the tracker so a complete fleet management history can be built. As well as offering an extra layer of security businesses can benefit from reports on journey times and inform their customers of delays. Combining vehicle tracking with a routeing system can save the business time and money by avoiding traffic and finding the quickest route.
dolgachov / 123RF Stock Photo