History
The Global Positioning System
(GPS) is a constellation of 24 active satellites and 3 additional
backup satellites. The GPS system was developed and implemented by the
United States Air Force (USAF) for operational reasons, and has since
become extensively adopted for individuals in the pursuit of outdoor
recreation, personal vehicle navigation, and a vast array of commercial
tracking, mapping, and reporting applications.
Principles
GPS works on the basic
principle of triangulation (determining position by calculating the
angles from which multiple signals have arrived). The GPS satellites
constantly send signals down to the earth, which are received and
processed by the GPS receiver, extracting latitude, longitude,
altitude, direction of travel, instantaneous speed, time of day, and a
list of the satellite signals received. In order to acquire location
accurately, it is necessary to “see” signals from at least four
satellites, although it is highly beneficial to see more than the
minimum. A properly mounted GPS receiver with an unencumbered view of
the horizon in all directions may see up to 12 different signals,
although on normal terrain it is more common to receive signals from
6-8 satellites.
Limitations
To derive the maximum benefit
from GPS tracking data, it is important to note the shortcomings of the
technology. First of all, GPS signals can not penetrate dense solids
such as metal and wood, so indoor use is not practical. Furthermore,
due to the very low signal levels received on earth, GPS receiver units
are often unable to acquire a good reading when shielded by dense
foliage. For this reason, it is important to mount the GPS receiver in
a location where it has the best visibility of the sky, normally on the
roof of the vehicle to be tracked.
Applications
The adoption of GPS tracking solutions has become widespread in recent
times, as fuel prices and other operating costs have soared. Using
iTRAK, fleet managers can dispatch mobile workers more efficiently,
ensure drivers adhere to authorized routes, and closely monitor the use
of company assets. Some fleet managers have reported fuel savings of
40% or more by using Mobile Resource Management (MRM) technologies such
as GPS.
Read more on the Benefits of GPS Vehicle Tracking.
