Position line explained

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.^[1]

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 interest^[2]
• 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

Notes and References

1. Web site: line of position. UNTERM. United Nations. 2026-01-24.
2. U.S. Army, Advanced Map and Aerial Photograph Reading, Headquarters, War Department, Washington, D.C. (17 September 1941), pp. 24-25 https://digital.library.unt.edu/ark:/67531/metadc28314/m1/33/?q=bearing