Mobile Spy Phone Glossary

Cell Phone GPS Basics Cell Phone GPS Basics Soon GPS will become almost as basic as the telephone, or more likely included with every mobile phone. GPS can determine positions accurate to a matter of just a few meters. In fact, incredibly with advanced equipment it is possible to make measurements to less than a centimeter! It’s just like assigning every square meter on the planet a unique address. GPS receivers have become very affordable as they have been miniaturized to just a few integrated circuits. Nowadays days GPS is becoming integrated into cars, boats, planes, construction equipment, movie making gear, farm machinery, laptop computers and especially smartphones. Tracking mobile phones is a popular topic with a lot of interest. Much of the discussion dealing with cell tracking, mobile GPS and mobile phone tracker software applications would be more meaningful with a GPS Satellite introduction and glossary. GPS is an acronym for Global Positioning System. GPS satellites broadcast signals from medium earth orbit that GPS receivers use to estimate three-dimensional location (latitude, longitude, and altitude) plus precise time. The GPS system is made up of 3 main 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 at a height of about 12,000 miles. These satellites are referred to as the GPS Constellation, and they make an orbit twice a day. 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 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 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 gravitational force and centrifugal forces are canceled and are in equilibrium. 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 move at about 7,000 mph to maintain position. This is just about the same speed as GPS satellites, but since earth-synchronous satellites are 10,000 miles further away they stay in place relative to the earth. The GPS Control Segment incorporates 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 mobiles 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 determine 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). Keep in mind that there is a basic difference between cell phone GPS Tracking and GPS Navigation. GPS phone tracking is normally associated with a third-party keeping records of either real-time or historical cell phone location, while Navigation deals with the cell phone user figuring out how to get from point A to point B. Neither use works without some sort of third-party software program. Global Satellite System Glossary of basic terminology. GPSThe Global Positioning System consists of 24 GPS satellites, portable GPS receivers, and various ground-based support facilities. GPS receiverThe either a standalone handheld device or electronic unit mounted on a vehicle dashboard or other movable item such as an ocean freight container, and now particularly common to be included with cell phones . Abbreviated “GPS” in common use. Global Satellite System FAQ Why does GPS receiver only work outside? GPS satellites are positioned in their orbits such that from any location on the globe there are at least four satellites visibile at any given time. Although the satellites use radio signals, the signal needs a clear of site to the receiver. Once the GPS satellite slips below, or a building, or even heavy cloud cover, the radio signal may be lost. What do the satellites do? The GPS satellites are broadcasting the time. Both the satellite and the GPS receiver use atomic clocks for extreme accuracy. By comparing the difference between the time given by the satellite and the time in the GPS receiver, the GPS can calculate the distance from the satellite. How do GPS satellites know their location? The satellites keep position stored internally in calculated tables. But they can deviate off course over time. To make adjustments, the satellite communicates with ground stations located around the globe. Each time it touches base with the ground stations, the satellite adjusts its internal position tables. Does a GPS receiver transmit information back to the satellite? No, they don’t do that. GPS equipped cell phones will send data but not to the satellite.