GPS tracking, cell phone GPS and cell phone GPS track software programs are getting a lot of interest from consumers, cell phone companies and application programmers. The latest cell phones integrate GPS location functions to track phone position.
GPS receivers, regardless of whether inside of a handset, or simply a specific Portable gps tracking device, compute specific location through precisely timing the signals passed on by GPS satellites. This information consists of the moment the message was sent, highly accurate orbital data (technically referred to as the ephemeris), along with the general system state and approximated orbits of all GPS satellites (technically referenced as the almanac). GPS receivers often take a long time to become ready to navigate after being turned on because it must acquire some basic information in addition to capturing GPS satellite signals. This slow start is sometimes caused if the GPS device has been turned off for days or weeks, or has been transported a far distance while turned off 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 acquire signals and calculate initial position faster.
GPS Hot Start is when the GPS enabled device keeps its last known position, the satellites that had been in range at the time, and also the almanac data in memory, and attempts to lock onto the same satellites and determine a fresh position based upon the previous information. This is almost always 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 is when the GPS enabled device recalls its last calculated location, and almanac used, but not which satellites were in view. It performs a reset and makes an attempt to lock onto satellite signals and computes a whole new position. The GPS receiver has a general idea of which satellites tolook for because it kept its last known position and the almanac data helps identify which satellites are in range. The Warm Start will take more time than the Hot Start although not as long as a Cold Start. With GPS Cold Start, the device deletes all the previous information, and attempts to find satellites and complete a GPS lock. This usually takes longer than other methods because there is no known reference information. The GPS enabled handset receiver has to attempt to lock onto a satellite signal from any accessible satellites.
So that you can have better GPS lock times mobile phone manufacturers and network operators created Assisted GPS technology. It downloads the ephemeris and helps triangulate the device general location. GPS Receivers will get a faster lock at the expense of a few kilobytes of data transmission. Assisted GPS, often known as A-GPS or AGPS, increases the performance of standard GPS in handsets connected to the cell network. In the United States Sprint, Nextel, Verizon Wireless, and Alltel all use A-GPS. Which is a method of utilizing the cell network to speed up acquisition of GPS satellites.
A-GPS assists location tracking functions of mobile phones (and also other related devices) in a couple of ways:
One method is by helping to acquire a more rapid “time to first fix” (TTFF). A-GPS acquires and stores data in relation to satellite location via the cellular network so the coordinates details does not require to be downloaded via the satellite.
The next technique is by assisting position handsets when GPS signals are weak or impeded. Because GPS satellite signals may be impeded by tall buildings, and do not pass through building interiors well Assisted GPS uses distance to cellular towers to approximate position when GPS signals are not readily available.
If satellite signals are not obtainable, or precision is less important than battery life, making use of Cell-ID is a viable alternative to GPS cell phone tracking. The location of the smartphone may be computed by the cellular network cell id, that identifies the cell tower the phone is using. By having the position of the tower, you may know approximately where the smartphone will be. Still, a tower can cover a large area, from a few hundred meters, in high populationdensity areas, to a few miles in lower density regions. This is why location CellID accuracy is lower than GPS accuracy. Even so tracking from CellID still can provide a truly helpful substitute.
Another way of determining handset position is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation makes use of signal analysis data to calculate the time it takes signals to travel from your cellular phone to no less than 3 cell towers to estimate location.
Details about Smartphone Programs for GPS Monitoring
No comments:
Post a Comment