A position line or line of position (LOP) is a line (or, on the surface of the Earth, a curve) that can be both identified on a chart (nautical chart or aeronautical chart) and translated to the surface of the Earth. The intersection of a minimum of two position lines is a fix that is used in position fixing to identify a navigator's location.
There are several types of position line: Compass bearing – the angle between a compass point and the line passing through the compass and the point of interestU.S. Army, Advanced Map and Aerial Photograph Reading, Headquarters, War Department, Washington, D.C. (17 September 1941), pp. 24-25 Transit – a line passing through the observer and two other reference points Leading line – the line passing through two marks indicating a safe channel Leading lights – the line passing through two beacons indicating a safe channel Sector lights – the lines created by masked colored lights that indicate a safe channel
See also
Coordinate line Intersection (aeronautics) Navigation Position circle Sight reduction
References