Showing posts with label gps satellite. Show all posts
Showing posts with label gps satellite. Show all posts

Thursday, October 31, 2013

Mobile Phone GPS Tracking Help

Throughout this discussion keep in mind that there is a fundamental difference between mobile phone GPS Tracking and Navigation. GPS cell tracking is usually associated with someone maintaining records of either real-time or historical cell phone position, while Navigation deals with the smartphone user figuring out 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 phone tracking, navigation requires third-party software.



 Tracking


A lot of the discussion dealing with GPS tracking, cell phone GPS and mobile phone tracking 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 made up of 3 primary segments: Space Segment, Control Segment and User Segment.


The GPS Space Segment made up 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 once every 12 hours. They are not geosynchronous, they travel at over 7,000 mph. They are solar powered but have battery reserve 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 properly positioned. 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 force of gravity and centrifugal forces are canceled and are in balance. This is the best location to park a communications satellite. The earth rotates at about 1,000 miles an hour, and because of their high earth orbit the earth-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 stationary satellites are 10,000 miles further away they stay in place relative to the earth.


The GPS Control Segment consists of 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 functioning correctly and the data they beam down to earth is accurate.


The GPS User Segment includes of GPS receivers taking the shape of handsets 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 function.


GPS receivers determine location by precisely timing the signals sent 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 device 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 the cellphone to at least three cell towers to determine position.


With Mobile Location Services (MLS), the GSM cell network provider utilizes triangulation techniques to compute the location of the device, its accuracy is proven to be less than than that of GPS. MLS is also impacted by factors similar to GPS in the sense of the barriers impeding signal strength and the density of GSM towers to help in the triangulation effort. In remote areas location accuracy may be off as much as a mile.



Mobile Phone GPS Tracking Help

Tuesday, September 24, 2013

A Brief Introduction To Smartphone GPS Tracking

Throughout this discussion keep in mind that there is a fundamental difference between mobile phone GPS Tracking and Navigation. GPS cell tracking is typically related to someone maintaining records of either real-time or historical cell phone location, while Navigation deals with the handset user figuring out how to get from point A to point B. Just because a cell phone has GPS doesn?t mean that it can easily be used as a navigation device. Just like phone tracking, navigation requires third-party software.


A couple of important technical capabilities relevant to GPS cell tracking to consider include: Tracking Application “Persistence”. The tracking application on a handset typically must be enabled by the user. Depending on the handset, the application may persist – remaining enabled when the phone is turned on after having been turned off. This feature can be especially usefull if cell tracking is relevant and you do not want to require the person using the phone to turn tracking on and off. Another thing relevant to Tracking Application “Persistence” and handset GPS location is the possibility of wasting the battery. It is important to be able to remotely adjust how often of taking GPS position. Selecting real-time or periodic sampling affects both the accuracy of determining position as well as battery life. One typical way of controlling battery and data use is Passive Tracking. Some smartphone GPS tracking devices will record location data internally so that it can be downloaded when preferred. Also referr


ed to as “data logging,” it can keep position information even when the device has traveled outside the wireless network. Passive tracking is not a universal feature built-in to standard cell phone, but the newest mobile phones tend to offer Passive tracking capability.


 Mobile Tracker


A lot of the discussion dealing with cell tracking, mobile GPS and mobile phone track 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 system that 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 also known as as the GPS Constellation, and they make an orbit once every 12 hours. They are not parked over one spot, but rather move at over 7,000 mph. GPS satellites are solar powered but have battery reserve for when they are in the earth?s shadow. They are placed so that at any given time 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 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 force of gravity and centrifugal forces are canceled and are in equilibrium. This is the ideal location to park 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 move at about 7,000 mph to maintain position. This is approximately the same speed as GPS satellites, but since they satellites are 10,000 miles further away they stay in place relative to the earth.


The GPS Control Segment consists of 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 functioning correctly and the information they send to earth is accurate.


The GPS User Segment consists 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 applications that make them work.


GPS receivers, no matter whether within a smartphone, or simply a spucific Portable gps tracking device, estimate position by way of precisely timing the signals transmitted by GPS satellites. This critical information includes the time the message was transmitted, accurate orbital details (technically called the ephemeris), and also the basic system status and rough orbits of all GPS satellites (formally called the almanac).


If satellite signals are not obtainable, or accuracy and precision is less important than life of the battery, using Cell-ID is a useful alternative to GPS smartphone tracking. The location of the mobile phone can be approximated by the cell network cell id, that determines the cell tower the smartphone is using. By understanding the position of the tower, you’ll be able to know roughly the place that the cell phone will be. Nonetheless, a tower can cover a large area, from a few hundred meters, in higher populationdensity regions, to several kilometers in lower density areas. For this reason location CellID precision is lower than GPS accuracy. Having said that location via CellID still delivers a really viable alternative.



A Brief Introduction To Smartphone GPS Tracking