From AMS Glossary
In satellite meteorology, parallax displacements are shifts in the apparent (or mapped) position along a reference ellipsoid of Earth's surface or atmospheric features (e.g., high terrain, clouds, lightning) due to non-nadir viewing geometry. Parallax displacements for features at altitudes above the reference ellipsoid occur in a direction away from the viewer, along the great circle defined by the subsatellite point and the subfeature point. The effect is maximized for high-altitude features observed at very oblique viewing angles, minimized for low-altitude features, and nonexistent for features observed at nadir.
Term edited 6 May 2019.