What type of GNSS error is caused by signal reflections?

Multipath errors occur when GNSS signals reflect off surfaces such as buildings, vehicles, or the ground before they reach the receiver. This reflection can cause multiple signals to arrive at the receiver at slightly different times, leading to inaccuracies in the calculated position. The receiver may then mistakenly interpret these delayed signals as coming directly from the satellites, which can distort the location data.

These errors are particularly prominent in urban environments where there are many surfaces for signals to reflect off. Understanding and mitigating multipath effects is essential for improving the accuracy of GNSS positioning. The other types of errors involve different mechanisms: atmospheric interference is related to changes in the ionosphere or troposphere affecting the signal, ephemeris errors are related to inaccuracies in the satellite's reported position, and selective availability, though no longer in effect, historically refers to intentional degradation of satellite signals by the U.S. government to limit accuracy for non-military users.