Throughout this discussion consider that there is a fundamental difference between cell phone GPS Tracking and Navigation. GPS phone tracking is usually associated with someone keeping records of either real-time or historical smartphone location, while Navigation deals with the handset 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 easily be used as a navigation device. Just like cell tracking , navigation requires third-party software.
Much of the discussion dealing with cell tracking, mobile GPS and cell phone track 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 system that is made up of 3 primary segments: Space Segment, Control Segment and User Segment.
The GPS Space Segment is comprised of 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 are orbiting twice a day. They are not geostationary, but rather move at over 7,000 mph. GPS satellites are solar powered but have battery reserve for when they are on the dark side of the earth. They are placed 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 runs out.
GPS Satellites are not communications satellites. Geostationary or communications satellites are parked in space 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 gravitational force and centrifugal forces are offset and are in equilibrium. This is the ideal location to park a stationary satellite. The earth rotates at about 1,000 miles an hour, and because of their high earth orbit the geo-synchronous satellites need to travel 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 don?t move relative to the earth.
The GPS Control Segment is composed 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 working to specification and the information they beam down to earth is accurate.
The GPS User Segment is composed of of GPS receivers taking the shape of devices and , laptops, in-car navigation devices and hand-held tracking units along with the people that use them, and the software programs that make them function.
GPS receivers often take longer to become ready to use after it’s turned on because it must acquire some basic information in addition to capturing GPS satellite signals. This delay is sometimes caused when the GPS cell phone has been turned off for days or weeks, or has been transported a significant distance while unused for. The GPS must update its almanac and ephemeris data and store it in memory. The GPS almanac is a set of data that every GPS satellite transmits. When a GPS receiver has current almanac data in memory, it can capture signals and find initial position more quickly.
If satellite signals are not obtainable, or accuracy is less important than battery life, making use of Cell-ID is a good alternative to GPS mobile phone tracking. The position of the handset may be computed by the cell network cell id, that determines the cell tower the cellphone is connected to. By having the position of this tower, then you can know roughly the place that the handset might be. Still, a tower can cover an enormous area, from a couple of hundred meters, in higher populationdensity zones, to a few kilometers in lower density areas. For this reason location CellID precision is less than than GPS accuracy. Even so location from CellID still supplies a very useful substitute.
A Short Intro To Mobile Phone GPS Tracking
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