Global Positioning System, or GPS, is a way to accurately determine the location of something on earth, and is considered one of the most important technologies of our time. It uses a combination of satellites and receivers to pinpoint the geolocation of these receivers along longitude and latitude coördinates. Information is supplied by around 30 purpose-built satellites orbiting the earth in fixed orbits. This information can then be interpreted by software the can display the position in a more user-friendly way by using map overlays.
GPS has a myriad applications, including military, civilian transport navigating, personal navigation, map making, climate studies, emergency location, as well as commercial applications such as fleet monitoring and courier tracking.
Initially developed by the United States Department of Defence, work on the system that would eventually become GPS as we know it today, started all the way back in 1957 when two physicists from Johns Hopkins University decided to monitor the radio signals from the recently launched Russian satellite, Sputnik 1. By using the Doppler effect, the change in frequency of a wave as it moves closer or farther away from its source, they discovered that they could track the position of the satellite as it orbited earth. The potential application of this ability was apparent, and a project was launched to reverse the technology to track objects on Earth.
However, only in 1973 did military officials realise the significant practical applications of this kind of system, such as tracking of ships, planes, and weapons. A project to develop what we know as GPS today was launched. By 1980, the system was opened for civilian use, but only on a limited basis. The program launched prototype satellites between 1978 and 1985. In 1983, President Ronald Reagan issued a directive that the system should be opened for civilian use once developed. By 1995, one year after the system became completely operational, President Bill Clinton signed a policy to open up the limited availability of the system for civilian use. This was eventually done in 2000, and since then use of GPS has soared, and has been playing in increasingly significant role on everyday life.
While GPS is open to the private sector, the US government still ons and operates the network, and it is required by international law that the US Department of Defence continuously maintains the service globally.
The GPS system consists of satellites and receivers, and works on what is known as trilateration, a mathematical principle that measures distance by using the geometry of shapes like circles, spheres or triangles. For a GPS system to work, receivers must know the location of at least three satellites, as well as the distance of these satellites from the receiver. This triangulation creates a 3 dimensional image of exactly where the receiver is located, including the direction and speed at which it is traveling, as well as the time.
There are 24 active GPS satellites at any given time, orbiting the earth at every 12 hours. There are also a number of ‘back-up’ satellites that can be activated in case one of the 24 fails. This network of satellites is known as the Global Navigation Satellite System, or GNSS.
While GPS operates independently of telecommunications networks, these can be used to enhance the accuracy of the system, as well as communicate and analyze data for various applications.
There are different types of GPS receivers, with data loggers, data pushers, and data receivers the most popular. Each of these are suited to different applications. The most popular of these are data loggers and data pushers.
Data loggers (Passive tracking)
Known as passive tracking, data loggers log and store data such as time, location, and various types of events on the device’s internal flash memory or memory card, at pre-determined intervals. This information can then be downloaded for analysis via a USB port or removable storage device, such as a memory card. Some data loggers send information wirelessly at certain intervals. This type of GPS tracking is often used in cameras to create geolocation and time tags on photographs.
Data Pushers (Active tracking)
The most common type of GPS tracking unit is called a data pusher, or GPS beacon. These types of trackers allow for active tracking by automatically ‘pushing’ data to centralized server in real time. Active tracking allows for instant analysis of tracked data, and is particularly useful in security applications such as vehicle and cellphone or computer tracking in the event of theft, as it provides authorities with the exact location of a vehicle. Other applications include monitoring commercial fleets, tracking people like children and athletes at a sporting events, as well as tracking courier deliveries.
Also known as GPS transponders, these units are always active, and differ from data pushers in that they don’t send information to a centralized server, but rather are queried by systems when needed. This is known as pull technology. This type of unit is not in wide use, and are usually installed property that run the risk of theft, or where a constant power source isn’t available, such as freight containers. While not currently not very common, it is gaining popularity due to the pairing of transponders with cellular phones that respond to special text messages.
On-board Diagnostics Trackers
On-board Diagnostics GPS trackers, or OBD GPS trackers, are GPS units that plug directly into a vehicle’s diagnostic port. These types of trackers are designed to gather much more detailed information about the vehicle than simply time, place, speed and direction. It includes things like fuel consumption, performance, wear and tear, and other diagnostic information. The unit uses its built-in antenna to transmit this data to a remote server, where it can be viewed and monitored. This type of GPS tracker is especially popular in light to medium commercial vehicles.
There is a common misperception that GPS trackers and navigation systems are the same. While they essentially work on the same principle and use the same technology, navigation systems provide location and driving directions, whereas GPS trackers either gather data about things like driving habits, or provide real time location data. These are often used in combination, known as telematics. This is tremendously useful for businesses that own and use fleets of vehicles, as well as vehicle security.
In commercial fleets, GPS is mainly used to keep track of where vehicles are, routes driven, general health of the vehicle, and mileage data for financial and maintenance reasons. Some units are also programmed to be triggered by certain events such as ignition, opening or closing of doors, especially freight and delivery vehicles, speeding, when the vehicle enters certain geographical areas, or when vehicles deviate from a set route. This kind of application leads to greater employee accountability and driver efficiency. Purpose-built software is often used for monitoring and analysis in order to make routes more efficient, or find vehicles in case of theft.
A major use of GPS in both fleets and private vehicles is security and theft tracking. GPS units are often hidden in the vehicle by specialist companies. In fact, many insurers require the installation of such devices as a requirement for insuring certain types of vehicles. Some insurers even use driving behavior to determine the risk level of a customer. This is used to determine premiums, and also down on false or inaccurate reporting on claims.
GPS tracking is a contentious issue, with many worried about invasion of privacy, monitoring by authorities or surveillance by other parties such as private investigators. With many web-based applications that can use tracking information, cyberstalking is always a concern. Every country has its own set of laws governing GPS tracking, but these laws are generally very similar. As a rule, you can track a vehicle or item if it belongs to you or a company. If it’s not your property, it’s usually illegal to install any kind of tracking device, unless specifically requested or agreed on by the owner. Thankfully the overwhelming majority of commercial applications fall well within the boundaries of the law. If you’re not sure, it is best you seek professional legal advice.
GPS teсhnology is one of the greatest, and most useful technologies of our time, and after more than half a century of development the system has become such a part of our lives that we almost take it for granted. One of the most useful applications of the technology is undoubtedly in vehicles, with GPS making it easier to get from Point A to Point B, making fleets more efficient and businesses more cost-effective, to countering theft. As both automotive and GPS technology evolve, the uses of GPS will only increase.