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The satellites continuously triangulate:

- Timing: The receiver measures the time delay between when the signal was

sent from the satellite and when it was received.

- This allows the distance to each satellite to be calculated.

- Positioning: By using the distances from at least three satellites, the

receiver can determine its position in two dimensions (latitude and

longitude).

The fourth satellite is used to determine the height (altitude) and correct for any

time differences between the satellites and the receiver.

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9.10.2 Precision and accuracy

Precision and accuracy are two important concepts in relation to GNSS and GPS.
Both precision and accuracy are essential for reliable navigation and positioning.

9.10.2.1 Precision

Precision refers to how close repeated measurements are to each other.

It is about consistency rather than how close they are to the true value.

A measurement can be precise without being accurate if it consistently gives the

same erroneous result.

GPS and GNSS can be very precise, especially in ideal conditions where signal

interference is minimal.

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 892