Satellites Find a Position

In the picture

1. 1Satellite: an orbiting source of radio signals
2. 2Signal beam: the path of a radio message from satellite to receiver
3. 3Meeting point: where distance ranges from four satellites intersect
4. 4Phone receiver: the device that measures signal travel times

Examples

• A map app showing your blue dot on a city street
• A car navigation screen recalculating a route after a turn

Quiz: Satellites Find a Position (Age 15)

1. 1

   How does a phone or car receiver use satellite signals to find its location?

   • It compares the signal strength from each satellite.
   • It sends a signal back to each satellite.
   • It measures how long each signal takes to arrive.
2. 2

   How many satellites are enough to determine a position in three dimensions?

   • Four
   • Two
   • Three
3. 3

   What does the receiver do with satellite signals?

   • It only sends a signal when it needs to update its position.
   • It sends a signal back to each satellite to confirm its position.
   • It listens to satellite signals and does not send a signal back.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.