Bearing Definitions for Land Surveyors
bearing—The direction of one point or object with respect to another, where the direction of the line is expressed by the acute angle with respect to a reference meridian. The reference direction can be North or South and the meridian may be assumed, grid, magnetic, astronomic, or geodetic. Typical bearings are N 60° 10′ E, S 31° 17′ W, N 17° 22′ W.
bearing, assumed—An arbitrary bearing base referred to a meridian chosen for convenience.
bearing, astronomic—The horizontal angle between the astronomic meridian and a line on the Earth.
bearing, back [USPLS]—The reverse direction of a line as corrected for the curvature of the line from the forward bearing at the preceding station. Important for control lines such as the secant and tangent and long triangulations. Thus the forward bearing of the secant at a township corner in latitude 45° is N 89° 57′ 24″ W (when the line is running westerly); at 3 miles from the starting point the back bearing is east, the forward bearing west; at the next township corner, 6 miles from the starting point, the back bearing is N 89° 57′ 24″ E. These are the true bearings in angular measure from the meridian at the point of record. See also bearing; azimuth, back.
bearing, forward-See bearing.
bearing, grid—See azimuth, grid.
bearing of line—The direction of a line; expressed by the acute angle with respect to a reference meridian or a north-south reference line.
bearing tree [USPLS]—A tree used as a corner accessory; its distance and direction from the corner is recorded, as is its species and size. Bearing trees are identified by prescribed marks cut into their trunks.
Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.
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