The principle of GPS positioning is:

The correct answer is: "intersection"

Key Points

• Principle of GPS Positioning:
  • GPS positioning is based on the principle of intersection (or trilateration).
  • The GPS receiver calculates its position by measuring distances from at least three or four satellites.
  • Each distance measurement forms a sphere around the satellite; the exact location is where these spheres intersect.
• How Trilateration Works:
  • From one satellite, the receiver could be anywhere on a sphere.
  • With two satellites, the position is narrowed to the circle where two spheres intersect.
  • With three satellites, the position is pinpointed to the intersection point of three spheres, giving precise coordinates.
• Additional Satellite for Accuracy:
  • A fourth satellite helps correct timing errors and improve accuracy by solving for the receiver’s clock bias.

Additional Information

• Transposition: A general term meaning swapping or exchanging positions; not related to GPS positioning.
• Radiation: Refers to emission of electromagnetic waves; satellites use radiation to send signals but it is not the positioning principle itself.
• Analytical Resection: A surveying technique to locate a point by measuring angles from known points, different from distance-based GPS positioning.