Cell Phone GPS Tracking Basics

A lot of the discussion dealing with GPS tracking, mobile 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 is an acronym 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 incorporates twenty-four to thirty-two satellites that orbit the earth at a height of about 12,000 miles. These satellites are also known as as the GPS Constellation, and they make an orbit once every 12 hours. They are not parked over one spot, but rather move at over 7,000 mph. They are solar powered but have battery reserve for when they are in the earth?s shadow. 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 flying in the correct path. The satellites last about ten years until all their fuel is exhausted.

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 balance. This is the ideal location to position a stationary satellite. The earth rotates at about 1,000 miles an hour, and because of their high earth orbit the geostationary satellites need to move at about 7,000 mph to maintain 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 includes Master Control Station, an Alternate Master Control Station, and numerous dedicated and shared Ground Antennas and Monitor Stations that work together to ensure the satellites are functioning to specification and the information they beam down to earth is accurate.

The GPS User Segment is comprised of of GPS receivers taking the shape of cell 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 function.

GPS receivers, regardless of whether in a smartphone, or simply a spucific Portable gps tracking device, calculate location through accurately timing the signals passed on by GPS satellites. This data comes with the moment the message was sent, specific orbital details (technically called the ephemeris), and also the overall system condition and determined orbits of all GPS satellites (technically referenced as the almanac).

If satellite signals are not obtainable, or accuracy is less important than battery life, employing Cell-ID is a useful substitute to GPS cell phone tracking. The position of the smartphone can be approximated by the cellular network cell id, that determines the cell tower the phone is connected to. By knowing the position of the tower, then you can know approximately the place that the handset might be. Still, a tower can cover a huge area, from a couple of hundred meters, in high populationdensity zones, to several kilometers in lower density regions. This is the reason location CellID precision is less than than GPS accuracy. Even so monitoring from CellID still can provide quite a useful alternative.

Cell Phone GPS Tracking Basics