First of all, it is important to clear any misunderstanding
surrounding the abbreviation GPS. GPS is not this tiny little gadget that you
hang on the front window of your car. This little screen is the GPS receiver.
GPS receiver
The GPS receiver essentially does what its name suggests; it receives radio waves emitted by satellites orbiting the globe. The GPS receiver interpret those waves and subsequently calculates its distance from the satellite.You will later learn how radio waves are used to calculate distance
In order to calculate an object's exact location on earth:
-At least 4 Satellites are needed in order to accurately locate an object on earth’s surface
You will learn later about the Whys of this specific number of Satellites.
You learned earlier(see the introduction to GPS text) that 4 Satellites are always visible in the sky at anytime at any point on earth; so the GPS will always have contact with the number of satellites required for localization(except from some unusual cases that we are not going to barge into)
Satellites
There are 27(24 operational, 3 spares) of these 3000-4000 pounds objects orbiting the earth at an altitude of 19 300 km . They complete 2 orbits of the earth in one day and they emit radio waves that travel at the speed of light(300 000 km/sec) since they are electromagnetic waves.
The ensemble of 24 satellites and the GPS receiver forms what we all the Global Positioning System.
A GPS receiver The Global Positioning System
GPS receiver
The GPS receiver essentially does what its name suggests; it receives radio waves emitted by satellites orbiting the globe. The GPS receiver interpret those waves and subsequently calculates its distance from the satellite.You will later learn how radio waves are used to calculate distance
In order to calculate an object's exact location on earth:
-At least 4 Satellites are needed in order to accurately locate an object on earth’s surface
You will learn later about the Whys of this specific number of Satellites.
You learned earlier(see the introduction to GPS text) that 4 Satellites are always visible in the sky at anytime at any point on earth; so the GPS will always have contact with the number of satellites required for localization(except from some unusual cases that we are not going to barge into)
Satellites
There are 27(24 operational, 3 spares) of these 3000-4000 pounds objects orbiting the earth at an altitude of 19 300 km . They complete 2 orbits of the earth in one day and they emit radio waves that travel at the speed of light(300 000 km/sec) since they are electromagnetic waves.
The ensemble of 24 satellites and the GPS receiver forms what we all the Global Positioning System.
A GPS receiver The Global Positioning System