Vertical position

Definitions

• depth: "distance of a point from a chosen reference surface measured downward along a line perpendicular to that surface."
• height: "distance of a point from a chosen reference surface measured upward along a line perpendicular to that surface";

• altitude: "height where the chosen reference surface is mean sea level"

• altitude: "the vertical distance of a level, a point or an object considered as a point, measured from the mean sea level ;"
• height: "the vertical distance of a level, a point or an object considered as a point, measured from an specific datum."

• ''elevation': "the vertical distance of a point or a level, on or affixed to the surface of the earth, measured from mean sea level."