GPS Information

Before long GPS will become almost as basic as the telephone, or more likely included with every cell phone.  GPS can calculate locations accurate to a matter of feet.  In fact, incredibly with advanced forms of GPS it is possible to make measurements to better than a centimeter!

In a sense it’s like assigning every square meter on the globe its very own address.  GPS receivers have become extremely economical as they have been miniaturized to just a few integrated circuits.  Nowadays days GPS is incorporated into cars, boats, planes, construction equipment, movie making gear, farm machinery, laptop computers and especially  phone handsets.

Tracking cell phones is a active topic getting a lot of interest.   A lot of the discussion dealing with GPS tracking, cell phone GPS and cell phone tracking software programs 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 network is made up of 3 main segments: Space Segment, Control Segment and User Segment.

The GPS Space Segment is composed 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 make an orbit once every 12 hours.  They are not geosynchronous, they travel at over 7,000 mph.  GPS satellites are solar powered but have battery backup 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 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 gravitational force and centrifugal forces are offset and are in equilibrium. This is the best location to place a communications 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 maintain 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 made up of 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 data they send to earth is accurate.

The GPS User Segment includes of GPS receivers  taking the shape of devices 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 work.

GPS receivers compute 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).

Consider that there is a fundamental difference between smartphone GPS Tracking and GPS Navigation.  GPS cell phone tracking is usually associated with someone maintaining records of either real-time or historical mobile phone  location, while Navigation deals with the mobile phone  user figuring out how to get from point A to point B.  Neither use works without some sort of third-party software application.

A very good software package that includes  remote control of device settings, and combines Cell Phone Tracking  with SMS text message, Call Log,  MMS multi-media message monitoring, and a web account for storage and review is PhoneBeagle.

Follow this link if you are interested in    Cell Phone Monitoring Software compatible with BlackBerry  and  Android  Smartphones, used or Parental Monitoring and Small Business Employee Monitoring .

Global Satellite System Glossary of basic terms.

GPS is made up of  24 GPS satellites, portable GPS receivers, and various ground-based support facilities.

The GPS receiver is typically a standalone handset  device or electronic unit mounted on a  automobile dashboard or other movable item such as a shipping container, and now particularly common to be included with  phone handsets . Abbreviated “GPS” in common use.

Visit this link for more information regarding the latest software for  Mobile Phone Tracking

Mobile communications means more than just making a phone call while on the move.    The most up-to-date smartphones have GPS locator features to track phone location.   These features, along with others such as text messaging, internet access and the capability to utilize other applications make smartphones great gadgets.  But GPS satellites aren’t always available, such as when the phone is in a building such as an office, shopping center, or even in an automobile.  That doesn’t mean cell phone tracking isn’t possible, but it does mean there are other methods of being a tracker.

To track a cell phone involves several main ways of calculating  smartphone position.  GPS Global Positioning System-Satellites, Triangulation, and CellID.   All these technologies convert mobile phones into mobile tracking devices.   These systems can be viewed as Network Based, Handset Based or a Hybrid approach.  GPS location is Handset based as it needs software applications installed on the mobile phone  in conjunction with GPS hardware.  Triangulation and CellID are Network Based as they use the equipment and data from the wireless provider.  Hybrid systems combine methods to make best use of available data and to make position cell phone tracking faster.

GPS on cell phones is what people usually think of when considering locating smartphones.   GPS (Global Positioning System) using satellites is the most popular and more accurate means of tracking.   But GPS needs satellites to be in direct line of site of the cell phone.

It doesn’t work as well indoors or in crowded cities.

If the phone is in a building, for example your school, restaurant.  Some mobile phones will retain the last known GPS location, others might not.

Another thing with handset GPS tracking is the possibility of wasting the battery.  It is important to be able to remotely adjust how often of taking GPS position.  Choosing real-time or periodic sampling affects both the resolution of determining position as well as how long the battery will last.

GPS receivers, whether in a smartphone, or a dedicated GPS tracking device, compute position by precisely timing the signals transmitted by GPS satellites.  This data includes the time the message was transmitted, precise orbital information (the ephemeris), and the general system condition and estimated orbits of all GPS satellites (the almanac).  GPS receivers often take a long time 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 slow start is sometimes caused if the GPS cell phone  has been turned off for days or weeks, or has been moved a far 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 find initial position more quickly.

GPS Hot Start is when the GPS enabled device  keeps its last known location, the satellites that were in range at the time, the almanac data in memory, and makes an attempt to connect to the same satellites and compute a new position based upon the previous data. This is almost always the quickest GPS lock but Hot Start only works if the phone is generally in the same location as when the GPS was last switched off.

GPS Warm Start is when the GPS enabled mobile phone  remembers its last calculated position, and almanac used, but not which satellites were in view. It resets and attempts  to obtain satellite signals and calculates a new position.

The GPS receiver narrows the choice of which satellites toseek because it kept its last known position and the almanac data helps identify which satellites are in range. The Warm Start will take longer than the Hot Start but not as long as a Cold Start.

With GPS Cold Start, the device dumps all the previous information, and attempts to locate satellites and achieve a GPS lock. This takes the longest because there is no known reference information.  The GPS enabled mobile phone   receiver has to attempt to lock onto a satellite signal from any available satellites.

Assisted GPS, also known as A-GPS or AGPS, enhances the performance of standard GPS in smartphones connected to the cellular network.   In America  Sprint, Nextel, Verizon Wireless, and Alltel all use A-GPS. Which is a method of utilizing the cellular network to accelerate acquisition of GPS satellites.  GPS Receivers can get a faster lock in exchange for a few kilobytes of data transmission.

A-GPS improves location tracking functions of cell phones (and other connected devices) in a couple of ways:

One way is by helping to obtain a more rapid “time to first fix” (TTFF). A-GPS acquires and archivesinformation about satellite locationusing the cell network so the position information doesn’t require to be downloaded via the satellite.

The second way is by helping position  smartphones when GPS signals are weak or blocked.  As mentioned before GPS satellite signals may be interfered with by tall buildings, and do not penetrate building interiors well. AGPS uses proximity to cellular towers to estimate location when GPS signals are not available.

If satellite signals are not available, or accuracy is less important than battery life, using Cell-ID is a good substitute to GPS mobile phone tracking.  The position of the handset can be computed by the cellular network cell id, which identifies the cell tower the phone is connected to.   By knowing the position of this tower, then you can know approximately where the mobile phone  is.  But, a tower can cover a huge area, from a few hundred meters, in high density areas, to several kilometers in lower density areas. This is why location CellID precision is less than than GPS accuracy. Nonetheless location using CellID still presents a very useful substitute.

Another method of formulating  cell phone location is Triangulation or Mobile Location Services (MLS).  Cell Tower Triangulation uses signal analysis data to calculate the time it takes signals to travel from your phone to at least three cell towers to determine location.

To comply with Federal Communications Commission guidelines, cell phone companies must be able to provide authorities with mobile phone latitude and longitude to an accuracy of 50 to 300 meters.   Cell Tower Triangulation doesn’t always meet this requirement.  For comparison commercially available GPS modules are able to achieve accuracy down to 3-10m.  This depends upon many factors, as GPS signals are often very weak and are impacted  by many environmental factors.   With Mobile Location Services (MLS), the GSM cell network provider utilizes triangulation techniques to try to pinpoint the position of the cell phone, its accuracy is proven to be less than 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 calculation.   In remote areas location accuracy may be off as much as a mile.

It may be important to consider how GPS location software applications handle the data and controls smartphone settings.   Having real time tracking on demand, or preferring to minimize battery use and data transmission should be offered.   Typically the application determines the location with a GPS receiver and transmits the tracking data to a server through a data connection. The data connection to the server is usually made via the Internet.  How often GPS samples are taken and how often and by what method the data is sent to the server affect effectiveness and costs.

Consider that there is a fundamental difference between mobile phone GPS Tracking and Navigation.  GPS cell tracking is usually associated with a third-party maintaining records of either real-time or historical smartphone  position, while Navigation deals with the cell phone  user figuring out how to get from point A to point B.

A really great software package that includes remote control of mobile phone settings, and combines Mobile Phone Tracking  with SMS text message, Call Log,  MMS multi-media message monitoring, and a web account for storage and review is PhoneBeagle.

Follow this link if you are interested in    Cell Phone Monitoring Software  compatible with BlackBerry  and  Android  Smartphones, used or Parental Monitoring and Small Business Employee Monitoring .

Visit this link for more information regarding the latest software for
GPS Tracking .