Throughout this discussion keep in mind that there is a basic difference between cell phone GPS Tracking and Navigation. GPS cell tracking is typically related to a third-party keeping records of either real-time or historical handset location, while Navigation deals with the handset user determining how to get from point A to point B. Just because a mobile phone has GPS doesn?t mean that it can necessarily be used as a navigation device. Just like cell phone tracking, navigation requires third-party software.
Much of the discussion dealing with GPS tracking, cell phone GPS and cell phone tracking software could be helped by a GPS Satellite primer.
GPS satellites broadcast signals from space that GPS receivers use to determine three-dimensional location (latitude, longitude, and altitude) plus precise time. GPS stands for Global Positioning System and is a network that is composed of 3 main segments: Space Segment, Control Segment and User Segment.
The GPS Space Segment includes twenty-four to thirty-two satellites that orbit the earth in medium earth orbit MEO. These satellites are also known as as the GPS Constellation, and they make an orbit once every 12 hours. They are not geosynchronous, but rather move at over 7,000 mph. GPS satellites are solar powered but have battery backup for when they are on the dark side of the earth. They are positioned so that there are at least 4 satellites ?visible? from any point on earth. Small rocket boosters on each satellite keep them properly positioned. The satellites have a lifetime of about 10 years until all their fuel is exhausted.
GPS Satellites are not communications satellites. Geostationary or communications satellites use a higher altitude 22,300 miles above the equator. These satellites are used for weather forecasting, satellite TV, satellite radio and most other types of global communications. At exactly 22,000 miles above the equator, the earth’s force of gravity and centrifugal forces are offset and are in equilibrium. This is the best location to place a communications satellite. The earth rotates at about 1,000 miles an hour, and because of their high earth orbit the geo-synchronous satellites need to move at about 7,000 mph to keep position. This is approximately the same speed as GPS satellites, but since stationary satellites are 10,000 miles further away they stay in place relative to the earth.
The GPS Control Segment consists of Master Control Station, an Alternate Master Control Station, and a host of dedicated and shared Ground Antennas and Monitor Stations that work together to ensure the satellites are working to specification and the data they beam down to earth is accurate.
The GPS User Segment is comprised of of GPS receivers taking the shape of mobile phones and , laptops, in-car navigation devices and hand-held tracking units along with the people that use them, and the software applications that make them work.
GPS receivers, no matter if within a mobile phone, or perhaps a spucific Portable gps tracking system, estimate position through precisely timing the signals passed on by GPS satellites. This information comes with the time the message was transmitted, accurate orbital details (technically referenced as the ephemeris), plus the basic system state and determined orbits of all GPS satellites (formally referred to as the almanac).
In the event that satellite signals are not accessible, or accuracy is less important than battery life, using Cell-ID is a useful alternative to GPS cell phone location. The location of the mobile phone might be calculated by the cellular network cell id, that recognizes the cell tower the cellphone is using. By having the location of this tower, you’ll be able to know approximately the location where the smartphone will be. However, a tower can cover an enormous area, from a few hundred meters, in higher populationdensity locations, to several kilometers in lower density areas. This is why location CellID accuracy is less than than GPS accuracy. Even so tracking from CellID still delivers a really helpful substitute.
A Short Introduction To Smartphone GPS Tracking
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