1. Averaging adjacent values according to some scheme. Involves filtering out higher frequencies. Often accomplished by use of a running window (q.v.). 2. Straightening a good, shallow reflection and using it as a reference to remove undesirable lateral velocity and topography variations. Also called datuming. 3. Smoothing (often flattening) a reflection in order to emphasize irregularities in nearby reflections (such as might be caused by reefs or other features).