Throughout this discussion keep in mind that there is a basic difference between handset GPS Tracking and Navigation. GPS mobile phone tracking is normally associated with someone maintaining records of either real-time or historical smartphone location, while Navigation deals with the smartphone user determining 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 tracking , navigation requires third-party software.
A lot of the discussion dealing with GPS tracking, mobile GPS and cell phone tracker 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 composed of 3 main segments: Space Segment, Control Segment and User Segment.
The GPS Space Segment consists 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 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 placed 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 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 force of gravity 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 geo-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 earth-synchronous satellites are 10,000 miles further away they don?t move relative to the earth.
The GPS Control Segment includes Master Control Station, an Alternate Master Control Station, and a host of dedicated and shared Ground Antennas and Monitor Stations that work together to make sure the satellites are working correctly and the information they send to earth is accurate.
The GPS User Segment incorporates 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 calculate location by precisely timing the signals transmitted 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 handset position is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation employs signal analysis data to compute the time it takes signals to travel from the smartphone to no less than 3 cell towers to judge position.
With Mobile Location Services (MLS), the GSM cellular network provider utilizes triangulation algorithms to calculate the position of the smartphone, its accuracy is proven to be much worse than that of GPS. MLS is further impacted by the same issues as GPS in the sense of the barriers affecting signal strength and the density of GSM towers to assist in the triangulation effort. In remote areas location accuracy may be off as much as a mile.
Mobile Phone GPS Tracking Basics
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