Cell tracking, mobile GPS and cell phone tracking software packages are really securing focus from consumers, cellular telephone companies and program creators. The most recent cell phones feature GPS position capabilities to track cellular phone position.
GPS receivers, regardless of whether in a mobile phone, or a specific Portable gps tracking system, calculate specific location through precisely timing the signals transferred by GPS satellites. This critical information contains the time the message was sent, specific orbital information (technically referred to as the ephemeris), and the overall system state and determined orbits of all GPS satellites (formally referenced as the almanac). GPS receivers sometimes take longer to become ready to navigate after it’s turned on because it must acquire some basic information in addition to capturing GPS satellite signals. This delay can be caused when the GPS smartphone has been unused for days or weeks, or has been moved 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 compute initial location faster.
GPS Hot Start refers to whenever the GPS enabled smartphone retains its last calculated location, the satellites that were in view before, as well as the almanac information in memory, and tries to find the same satellites and compute a new location based upon the previous data. This is generally the quickest GPS lock but Hot Start only works if the phone is in the same general area as when the GPS was last switched off. GPS Warm Start refers to when the GPS enabled device remembers its last known location, and almanac used, but not which satellites were in view. It resets and attempts to obtain satellite signals and computes a new position. The GPS receiver narrows the choice of which satellites tolook for because it saved its last known position and also the almanac data helps determine which satellites are within view. The Warm Start will take more time than the Hot Start although not as much as a Cold Start. With GPS Cold Start, the device dumps all the previous data, and tries to find satellites and achieve a GPS lock. This takes the longest since there is no known reference data. The GPS enabled device receiver must try to lock onto a satellite signal from any available satellites.
To be able to have better GPS lock times cellular manufacturers and system operators created Assisted GPS technology. It downloads the ephemeris helping triangulate the mobile phone basic location. GPS Receivers can get a faster lock in exchange for a few kilobytes of data transmission. Assisted GPS, also referred to as A-GPS or AGPS, increases the performance of standard GPS in cell phones connected to the cellular network. In America Sprint, Nextel, Verizon Wireless, and Alltel all use Assisted GPS. This is a means of using the cellular network to accelerate finding of GPS satellites.
A-GPS improves location tracking performance of cell phones (along with other connected devices) in two ways:
One method will be helping to acquire a more rapid “time to first fix” (TTFF). A-GPS gets and stores data concerning the location of satellites via the cellular network and so the coordinates data does not need to be downloaded from the the satellite.
The next approach is by helping locate handsets when GPS signals are weak or blocked. Because GPS satellite signals may be impeded by tall buildings, and do not go through building interiors well AGPS makes use of distance to cellular towers to calculate location when GPS signals are not obtainable.
When satellite signals are not readily available, or precision is less important than life of the battery, using Cell-ID is a good substitute to GPS smartphone tracking. The location of the smartphone may be approximated by the cell network cell id, that pinpoints the cell tower the cell phone is using. By knowing the location of this tower, you’ll be able to know roughly where the cell phone will be. Still, a tower can cover an enormous area, from a few hundred meters, in higher populationdensity regions, to several miles in lower density areas. For this reason location CellID precision is lower than GPS accuracy. Even so monitoring via CellID still can provide a very handy substitute.
Another way of calculating mobile phone location is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation uses signal analysis data to compute the time it takes signals traveling from the phone to a minimum of three cell towers to estimate location.
Smartphone GPS Fundamentals
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