This is a Guest Post by Allen Jame, who is a follower of “What’s On My PC”. Thank you Allen for sharing these facts about GPS Technology with my readers…
GPS a space-based satellite system which provides location details.
The US government created this system.
It is easily and freely accessible to anyone who has a GPS receiver.
GPS is used to detect many cybercriminal activities too. To know about some cyber issues read this.
In this article, you will witness some mind-blowing facts about GPS.
Some of the main points discussed in this article are:
- Determine accurate time
- An alternative to GPS
- Einstein’s theory of relativity
- 32 GPS satellites
- Cell phone tracking when powered off
- Doppler’s effect on GPS
- Geotagging feature in GPS-capable cameras
- GPS satellites in line of sight
- The shape of antennas
- GPS in automobiles
1) Determine Accurate Time
GPS is not all about navigation.
It is also used to find the accurate time too.
- The GPS satellites consist of time signals and atomic clocks.
- GPS receivers use this signal to determine the time.
- These signals are also used in cell phone network for time synchronization.
2) Alternative to GPS:
The European Space Agency and EU are now working on an alternative to GPS, known as ‘Galileo.’
- It will have a unique feature called ‘Search and Rescue Service.’
- With this feature, the distressed signals could be easily picked up from anywhere on the Earth.
This system will most probably be completed by 2019.
3) Einstein’s Theory of Relativity:
Einstein’s theory of relativity says that times moves faster for the objects that are far from the source of gravity.
The onboard clock of satellites run faster than the clocks on the Earth surface because the satellite is further from the Earth.
Thus a second is almost eight microseconds longer for a GPS satellite that is traveling at 9000mph as compared to the GPS unit on the ground.
To overcome this issue, your GPS unit is programmed in a way that adjusts this difference.
4) 32 GPS Satellites:
Currently, there are 32 GPS satellites in orbit.
Initially, there were only 11 satellites for GPS, but as the demand for the more features increased, 13 more satellite had to be launched in the sky.
24 satellites are required for global coverage in GPS.
The first of this 24 satellite was launched in 1989, and the 24th satellite was launched after five years in 1994.
GPS satellites require servicing. They last for about ten years.
This is the reason there are currently 32 GPS satellites in orbit.
The extra ones fill in the go when any of the 24 satellites are repaired or needs to be serviced.
In this way, the coverage is maintained.
5) Cell Phone Tracking When Powered Off:
Now almost all smart devices have built-in GPS modules.
There also a free smart-phone GPS navigation app that works without internet.
You might be surprised to know that GPS works when your phone is turned off too.
Very few consumers know that GPS can still track their cellphones in such case.
This is because phones perform some limited functions even when they are switched off.
If you intend to cut off GPS tracking entirely then remove the battery from your phone.
There are some other methods that you can use to turn off GPS tracking.
A) Airplane Mode:
You can turn it off by putting your phone on airplane mode
But this trick doesn’t work on every cell phone.
This refers to intentionally causing interference in the GPS signals by using a device called the transmitter.
- Although this process is straightforward to do, it is much easier to detect also.
- Jamming the signals of GPS is illegal too.
This refers to fooling a GPS receiver by providing false information about the position, time and velocity
6) Doppler’s Effect on GPS:
The fundamental principle used in the GPS system is the Doppler Effect.
Our location is determined by the change in signal frequency from the GPS satellites.
7) Geotagging Feature in GPS-Capable Cameras:
At Chinese borders, many of the geotagging features are automatically disabled in the GPS capable photo cameras.
This is because of a chines law that prohibits is surveying and taking pictures without any license.
8) GPS Satellites in Line of Sight:
At least 4 GPS satellites are required at the line of sight to determine the location of any individual.
This magic number is four because of the way GPS determines your exact location.
The signals which satellite sends includes:
- Time at which the message is sent out.
- The position of the satellite relative to the earth’s center.
The distance between you and the satellite multiplied by the speed of light gives the time that signal takes to reach you from GPS satellite.
By doing some geometry, the position of the satellite is determined.
Then by using the location of the satellite and the known distances we can easily figure out our position.
9) The Shape of Antennas:
GPS antennas are mushroom shaped.
These antennas need to be installed away from the magnetic field with an unobstructed view of the sky.
10) GPS in Automobiles:
GPS was first used in automobiles in 1996.
Global Positioning system works in almost all weather conditions.
It uses satellites to find our location.
Due to its multi-channel design, GPS receivers are much accurate.
There are no setup charges of this system.
Author Bio: Allen Jame is a blogger and a web developer. Allen loves reading and writing blogs.