NatGEO

GPS

GPS (Global Positioning System ) is a satellite based technique where 24 satellite, currently 30 satellites are used in 6 orbits to monitor entire earth surface. It not only helps to identify exact location of any place but also very useful for different military activities.

Theses all information are quite well known fact about GPS but today we will discuss about GPS device and how it works and its extensive use in our daily life.

GPS Mechanism  - The network has been set up by 30 satellites orbitting around the earth with an                                      altitude of 20000 kms. Among these satellites atleast 3 will coincide with their network and send their data regarding latitude, longitude and height of the  place from MSL. This operation is based on a simple mathematical principle called Trilateration.

 These satellites will rotate around the earth in sun-synchronous manner with a definite interval. Now the signals which are sent to the device in a speed of light will be processed in a few seconds and display the designated data. GPS satellites have atomic clocks to keep accurate time.

Device Mechanism -  Our ancestors did a great job to frame a map by doing extreme level of calculation and measurements. Now a days we can easily find out any place over the earth surface without knowing them well by help of a small device called GPS receiver.

There are 27 satellites ( 24 are in operation and 3 are extra) orbiting the Earth by making two complete rotation in a day from the height of approx 20000 kms from MSL. A GPS receiver's job is to locate 4 or more satellites, find out their distance from each of them and finally find out it's own location. To do this receiver has to know two things -

1.  The location of at least 3 satellites
2.   The distance between the device and each of those satellites.

The GPS receiver figure out these two things by analyzing high frequency, low power radio signals from satellites. These radio waves are electromagnetic energy which travel at a speed of light. The receiver can calculate how far the signals has traveled by timing how long it took to arrive. Satellites start transmitting the signals in the form of pseudo-random code and receivers start to receive the same  with a little lag of time which is exactly equals to travel time of the signals. The receiver multiplies this time by the speed of light to determine how far the signal traveled.

In order to do this measurement the satellite and receiver's clock have to be synchronized down to the nanosecond. To make satellite positioning system by using synchronized clock, both the devices and satellite have to use atomic clock which are very expensive. To overcome this problem the device resets its clock to be in synchronize with satellite's atomic clock. The receiver does it constantly whenever its remain on, which means accuracy become as atomic clocks used in satellites.

Once the receiver able to do this calculation , it can tell you Lat. , Long. , and Altitude of your current position. To make this navigation more user friendly, most receivers plug this raw data into map files stored in memory. A standard GPS receiver will not only place you on a map at any particular location, but will also trace your path across a map as you move. If you leave your receiver on, it can stay in constant communication with GPS satellites to see how your location is changing.

Application in Daily life -  Such GPS systems are used widely in navigation purposes like live                                                        mapping, tracking any gadgets, cab driving and many more. Here are some few possibilities and benefits in our busy and hectic life.

1. Know where your children are using GPS tracker device with them
2. Keep tracking of your elder family members in their trip, so that they don't wander off alone.
3. Book a cab like UBER using GPS and know their location when you are in rush.
4. Track your electronic gadgets like mobile phone, camera, laptops if lost them in some where.
5. Plan a road trip around interesting points, landmarks with a specific track by helping GPS devices.
6. Get emergency road side assistance with traffic updates for reaching a place within a short time.
7. In aviation and shipping transport GPS is widely used in state of Radar for navigation.
8. Find different amusement points easily like restaurants, movie points, park, museum etc with an          associate route direction in pre-loaded maps like google map.
9. With the help of GPS surveying landscapes, buildings and large infrastructure can be done easily.         Also it is used in mapping sector, including aerial mapping GIS.

                         

 

Such GPS devices and trackers are available in different online and offline stores in worldwide in a cheap rate and some recent smartphones can also be used as GPS device with their in built technology.