GPS is global positioning system to determine the pinpoint position on the globe. Looking at the procedure as how GPS works the basic equipment requires to calculate the correct location and time. With the help of this equipment we can find out global navigation of any object in and around the planet earth.
Satellites: There are 24 satellites making a constellation around earth. These satellites are in six orbital planes having four satellites in each plane. And special thing about these orbits is that for a short while four satellites one from each plane possibly comes in the range of line of sight of the control units. This increases the authenticity of calculation.
Control Unit: MCS is a master control station. In case of any inconveniency, there is an alternate master control station. Also there are four antennas to navigate the update information. There are total six monitoring stations to calculation the accurate time and location.
Receivers: GPS receiver has some basic features as antenna matching with the frequency obtained from satellites. Then there is a processor unit and a reliable clock. Normally it is mentioned on the receiver that how many satellites it can capture to locate the position.
How GPS works
GPS satellites are continuously travelling around the globe. They complete nearly two rounds in one day. They are monitoring the globe and works as security agents. In case of any disposition on the earth or around the earth these satellites send information which is receives by the control units. The gist of the mechanism of GPS is the comparison of time difference when the information is sent by the satellites and the time when it reaches on the earth. This enables the receiver to calculate the position of a desired object. The information received on the navigation screen makes different angles as; North Pole is considered zero point and the difference is evaluated with respect to this point. Earth is taken as matrixes in which every cell means area has a specific address that are known as coordinates. These point are calculated by longitude and latitude cross points. GPS devices are so powerful and accurate that with the help of them we can navigate far off places.
2D position in which longitudinal and longitudinal measurements obtained are possible from three satellites locked at certain point and monitor movement of the object. 3D position in which longitudinal, latitudinal and altitudinal measurements obtained are possible with the help of four satellites in view.
After calculating user’s position, it becomes easy for the GPS unit to give reliable result. This becomes possible due to comprehensive model of the receivers. These calculations are measured with the help of channels. There are maximum 12 channels receivers that can lock the satellites movement and are capable of monitoring dense forests and skyscraper locales. However there are certain aspects that can be affected on the results. Among these are include the concrete structure and rocky mass. There are some atmospheric conditions like ionosphere and troposphere which creates a delay in the monitoring of and there comes doubt in the results. It happens that a receiver’s clock is not a reliable clock and gives erroneous result.
GPS provides following information;
A Pseudorandom Code: This is identification number of the specific satellite sending data.
Ephemeris Data: This record the date and time when information is sent through satellite. Also it tells about the deterioration of the satellite.
Almanac Data: This is recording the movement of satellites in their orbits. As satellites are continuously travelling in their orbits it is tracking the position of satellites.