In a recent paper Vicar & Körner (2012) in Oecologia (doi:10.1007/s00442-012-2416-7) clarified the use of elevation, altitude and height that have been used with confusion in literature. Here, I report from their note the definition of these terms, which sometimes have been misused from translations between Romanic languages.
Elevation is the vertical distance between a point on the land surface and a reference point, usually taken to be the mean sea level.
Altitude is the vertical distance between an object (e.g., a bird, aircraft, or parcel of air) and a reference point or stratum, where the object is not in direct contact with the reference point/stratum.
Height is the vertical distance between the top of an object and the land surface, where the object is in direct contact with the ground.
I thought some of you will be interested...