3.4.7.1. Trilateration

Try these first

1. 1.

   What is trilateration?

   Hint

   Think about how we find locations using satellites.

2. 2.

   How many satellites are needed for a three-dimensional position fix?

   Hint

   Consider how you can represent position in latitude, longitude, and altitude.

3. 3.

   What is the minimum number of satellites required for a three-dimensional GNSS position?

   • 2
   • 3
   • 4
   • 5

   Hint

   Think about how many dimensions you need information in!

4. 4.

   True or False: Trilateration can only determine a location using two satellites.

   • True
   • False

   Hint

   Consider how many signals you need for different dimensions.

5. 5.

   Suppose you are receiving signals from three satellites positioned at known locations, and the signal times indicate distances of 500 km, 300 km, and 400 km from these satellites. Describe how you would calculate your exact position on Earth.

   Hint

   Visualize how the spherical intersections would help locate you.

6. 6.

   During a survey, your GNSS receiver suddenly loses signal from one satellite but has strong signals from two others. Discuss how this affects your position estimate.

   Hint

   Think about how many dimensions are left unaccounted for!