Throughout this discussion keep in mind that there is a fundamental difference between mobile phone GPS Tracking and Navigation. GPS cell tracking is usually associated with someone maintaining records of either real-time or historical cell phone position, while Navigation deals with the smartphone user figuring out how to get from point A to point B. Just because a cell 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.
A lot of the discussion dealing with GPS tracking, cell phone GPS and mobile phone tracking software could be helped by a GPS Satellite primer.
GPS satellites broadcast signals from space that GPS receivers use to provide three-dimensional location (latitude, longitude, and altitude) plus precise time. GPS stands for Global Positioning System and is a network that is made up of 3 primary segments: Space Segment, Control Segment and User Segment.
The GPS Space Segment made up of twenty-four to thirty-two satellites that orbit the earth at a height of about 12,000 miles. These satellites are referred to as the GPS Constellation, and they make an orbit once every 12 hours. They are not geosynchronous, they travel at over 7,000 mph. They are solar powered but have battery reserve 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 last about ten years until all their fuel is exhausted.
GPS Satellites are not communications satellites. Geostationary or communications satellites are at a much higher orbit of about 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 canceled and are in balance. This is the best location to park a communications satellite. The earth rotates at about 1,000 miles an hour, and because of their high earth orbit the earth-synchronous satellites need to travel at about 7,000 mph to keep position. This is just about 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 numerous dedicated and shared Ground Antennas and Monitor Stations that work together to make sure the satellites are functioning correctly and the data they beam down to earth is accurate.
The GPS User Segment includes of GPS receivers taking the shape of handsets 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 function.
GPS receivers determine location by precisely timing the signals sent by GPS satellites. This information includes the time the message was transmitted, precise orbital information (the ephemeris), and the general system health and rough orbits of all GPS satellites (the almanac).
Another method of determining device position is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation makes use of signal analysis data to calculate the time it takes signals to travel from the cellphone to at least three cell towers to determine position.
With Mobile Location Services (MLS), the GSM cell network provider utilizes triangulation techniques to compute the location of the device, its accuracy is proven to be less than than that of GPS. MLS is also impacted by factors similar to GPS in the sense of the barriers impeding signal strength and the density of GSM towers to help in the triangulation effort. In remote areas location accuracy may be off as much as a mile.
Mobile Phone GPS Tracking Help
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