datum plane

British  

noun

1. surveying the horizontal plane from which heights and depths are calculated

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Example Sentences

In all maps that are to be contoured some plane, called the datum plane, must be used to which all contours are referred.

From Manual of Military Training Second, Revised Edition by Moss, James A. (James Alfred)

These movements are most conspicuous along coasts, where they can be referred to the datum plane of sea level; we will therefore take our first illustrations from rising and sinking shores.

From The Elements of Geology by Norton, William Harmon

Although it serves our convenience to refer the movements of the crust to the sea level as datum plane, it is understood that this level is by no means fixed.

From The Elements of Geology by Norton, William Harmon

The datum plane generally used in maps is mean sea level, hence the elevations indicated would be the heights above mean sea level.

From Manual of Military Training Second, Revised Edition by Moss, James A. (James Alfred)