What should be ensured for accurate positioning in GPS navigation?

To achieve accurate positioning in GPS navigation, it is essential that at least three satellites are being tracked. This is because GPS operates on a trilateration system, which calculates the user's location based on the distance from multiple satellites. Each satellite provides a signal that includes its location and the time the signal was sent. By determining the time it takes for the signal to reach the receiver, the GPS can calculate how far away each satellite is.

With data from three satellites, the GPS can pinpoint the user's position in two dimensions—latitude and longitude. If a fourth satellite is accessible, it allows for the calculation of altitude as well, providing three-dimensional positioning. Thus, tracking at least three satellites is crucial for accurate positioning in GPS navigation.

The other options represent considerations that may influence GPS usage but do not directly ensure accurate positioning. For instance, while it is beneficial for the receiver to be stationary for precise readings, movement can still allow for accuracy if multiple satellites are being tracked. Clear weather can improve signal strength, but advances in GPS technology have made it possible to receive signals in various weather conditions. Finally, calibrating a compass, though important for traditional navigation, is not a requirement for GPS functionality as the system relies on satellite signals rather than magnetic