Page 891 - engelsk
P. 891
Navigation
The fourth satellite is used to determine the height (altitude) and correct for any
time differences between the satellites and the receiver.
Back to Table of Contents
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.
9.10.2.2 Accuracy
Accuracy refers to how close a measurement is to the true value or actual
location.
Typically, GPS and GNSS can provide an accuracy of:
- Standard GPS: About 5 to 10 meters.
- Differential GPS (DGPS): 1 to 3 meters (uses a network of fixed land stations
that know their precise position. These stations calculate errors in the GPS
signals and send corrections to GNSS receivers)
Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 891
