GPS, which stands for Global Positioning System, is a satellite navigation system that can ascertain the latitude and longitude of a GPS receiver device on the Earth.
The GPS consists of more than two dozen global positioning satellites orbiting the earth. Each satellite transmits radio signals, which can help determine the location, speed and direction of travel of users equipped with GPS receivers. To ensure that the whole world is covered by the constellation of the GPS satellites, they are so arranged that four satellites are positioned in each of six orbital planes.
GPS tracking unit can determine the precise location of any individual or vehicle carrying the GPS receiver. Data about location and other aspects can be stored in various forms, depending on the type of tracking unit. The location of the object or individual being tracked is often recorded at regular intervals. Recording of an object can take place within the GPS receiver unit, or can be transmitted to a central location such as a database, where it can be accessed either via mobile technology or over the internet. GPS tracking systems can typically be viewed in real-time and have a map in the background to display the current location of an object.
GPS tracking units are divided into three categories, based on the techniques of data logging and retrieval.
Data Loggers: A GPS data logger logs the position of the object at regular intervals and stores the information in flash-based memory. Data on the memory can be retrieved or transferred to other stores with the help of available USB connectivity. Such devices are suitable for long distance hikers and cycling enthusiasts, who can make use of the logging facility to chalk out future routes to be followed.
Data Pushers: The GPS data pushers are popular for security purposes. This unit sends data from the device to a central database at regular intervals, updating information on location, direction, speed and distance. Such devices are suited for monitoring fleets of trucks and delivery vehicles. Vehicles can be located instantly in order to carry out effective supervision and prevent theft. Since it is easy to track movements of individuals or vehicles carrying valuable items, GPS data pushers are often used for spying.
Data Pullers: A GPS data puller allows the user to 'pull' data from the receiver as frequently as needed. The device remains on at all times. Though it is not as commonly used as the pusher device, it is particularly useful for tracing stolen goods. A mobile phone with integrated GPS can reply to an Glossary Link SMS from the data puller. This technology finds use in situations where tracking is required to be done only rarely.
GPS signals available to civilian GPS receivers can be used to compute position to within 10 meters (33 feet) most of the time. However, the precision of the GPS signals is sometimes intentionally diluted in certain sensitive areas based on national security needs.
GPS signals are available all over the world. However, please note that GPS receivers need signals from three or more satellites to compute position and, in general, this requires that an antenna connected to the GPS receiver be placed with a clear view of the sky. GPS reception may be inconsistent in certain locations or under certain conditions, such as:
Telemetry is the remote measurement or the remote collection of data which can be physical, environmental or biological.
Telemetry is typically used to gather data from distant, inaccessible locations, or when data collection would be dangerous or difficult for a variety of reasons. In telemetry, specialized instruments perform measurements of physical quantities, and store or transmit the resulting signal - sometimes after some initial signal processing or conversion.
Telemetry saves time, reduces overheads, improves customer satisfaction, provides additional selling features and in many applications has a rapid payback. The low cost of ownership coupled with the expertise of Powelectrics ensures a cost effective and reliable solution is always available.
The word has a few uses but more commonly, telematics have been applied specifically to the use of Global Positioning System technology integrated with computers and mobile communications technology in automotive navigation systems. Most narrowly, the term has evolved to refer to the use of such systems within road vehicles, in which case the term vehicle telematics may be used.
Vehicle telematics systems may be used for a number of purposes, including collecting road tolls, managing road usage (intelligent transportation systems), pricing auto insurance, tracking fleet vehicle locations (fleet telematics), recovering stolen vehicles, providing automatic collision notification, location-driven driver information services — and more particularly, dedicated short range communications DSRC in-vehicle early warning (car accident prevention) notification alerts.
Vehicle telematics systems are also increasingly being used to provide remote diagnostics; a vehicle's built-in system will identify a mechanical or electronic problem, and the telematics package can automatically make this information known to the vehicle manufacturer service organization. The telematics monitored system is also capable of notifying any problems to the owner of the vehicle via e-mail. Other forthcoming applications include on-demand navigation, audio and audio-visual entertainment content.
But the telematics industry is not limited to automotive applications. Other applications are being studied or developed for monitoring water and air pollution, for medical informatics and health care, and for distance learning. Many European countries are developing uniform policies to integrate telematics applications into government, business and education.
GPRS (General Packet Radio Service) is a digital, IP-based wireless packet data service offered by GSM-based cellular carriers (Cingular & T-Mobile in USA and the significant majority of cellular providers internationally).
AVL stands for Automatic Vehicle Location. It combines a GPS receiver with a wireless radio for providing location of a vehicle to a dispatcher. The AVL unit is usually installed inside a vehicle. The GPS receiver in the AVL unit receives GPS signals continually and computes the current position of the vehicle. The wireless transmitter contained in the AVL unit uses cellular, satellite or other wireless data communication methods to periodically transmit the location of the vehicle (obtained by the GPS receiver) to a Network Operations Center (NOC). From the NOC, the data usually travels through the Internet to the desktop computer of a Fleet Operations Manager/Dispatcher. The position data transmitted by the AVL unit is combined with mapping and other data and laid out in a manner suitable for Fleet Management decision making.
An AVL unit is usually connected to a car/truck/tractor and derives its power from the vehicle. Trailer Tracking units are similar to AVL units except that they are mounted on mobile assets, such as trailers and containers that do not have an inbuilt power source. These units use a self-contained battery and extensive power management to report the location of the asset a few times a day. If the battery is re-chargeable, it usually gets charged when a power unit, such as a tractor, attaches to the trailer. Otherwise, Trailer Tracking units use long life non-rechargeable batteries lasting 5 to 10 years.
All of our products provide data in real-time (as it happens) or near real-time, as far as possible. This means that each position update is sent by the AVL unit as soon as that update is due. This is quite different from many systems that claim to be real-time AVL but actually accumulate position updates within the device and then send the data by wirelessly connecting just a few times a day.
Occasionally, there are situations where the data cannot be physically transmitted by AVL units in real-time due to no/poor coverage. Globotrack Intelligent Coverage Sensing technology provides maximum 'real-timeliness' of data while ensuring minimum data loss. When AVL units move in areas that have no/poor cellular coverage, the periodic position updates are stored within the device. As soon as the units move back into good coverage areas, these stored updates are transmitted by the AVL units.