3.4.2. Basic principle of GPS

Try these first

1. 1.

   What is the main principle that GPS relies on?

   Hint

   Think about how locations are determined by distance.

2. 2.

   Define ellipsoidal height.

   Hint

   It relates to the surface shape of Earth.

3. 3.

   What principle is the GPS based on?

   • Triangulation
   • Trilateration
   • Linear Measurement

   Hint

   Remember we discussed this particular term in class.

4. 4.

   True or False: At least four satellites are needed to determine a GPS location.

   • True
   • False

   Hint

   Think about synchronization issues we talked about.

5. 5.

   You are given signals from five GPS satellites. Four satellites transmit their exact distances accurately, but one signal is weak and inaccurate. Discuss how the accuracy of the position calculations will be affected and what steps can be taken to improve reliability.

   Hint

   Think about the role of signal strength and its impact on accuracy.

6. 6.

   Draw and explain the difference between ellipsoidal height and orthometric height, indicating where the geoid fits in the diagram.

   Hint

   Use your previous knowledge of both concepts to illustrate effectively.