reduction to sea level

reduction to sea level

[ri′dək·shən tə ′sē ‚lev·əl]
(engineering)
The application of a correction to a measured horizontal length on the earth's surface, at any altitude, to reduce it to its projected or corresponding length at sea level.
References in periodicals archive ?
There are two methods for achieving this: The first is the altimeter setting all pilots know and love, and the second is referred to as a "reduction to sea level pressure (SLP)."