Flashcards in P3.3.3 Detecting Position Deck (12)
What type of waves do your television or radio receive to get information?
What does GPS stand for?
Global Positioning System
How many satellites does GPS use?
24 satellites in orbit around the Earth. They transmit radio waves.
How does GPS work?
1) Calculates distance from a measurement of time
2) Radio waves travel at the speed of light, 300 000 000 m/s
3) A GPS receiver detects signals from 3 satellites. From this it can work out your position.
What does GPS require to work?
It needs line of sight.
What is line of sight?
There needs to be a direct line from your receiver to the satellite.
What does radar stand for?
Radio detection and ranging
How does radar work?
1) Radio waves bounce off metal objects
2) You can find the distance using the time the reflected radio waves takes to travel
3) For radio waves, you need to use the speed of light (300 000 000 m/s)
How do astronomers find distances to objects in the Solar System?
How do astronomers find distances to objects outside our Solar System?
How does parallax work?
Stars appear to be in different places in June and December. So you can use mathematics to work out how far away they are.