Deck bearing
The deck bearing is a method for determining one's own geographic location. It is the most precise method for determining a position line in terrestrial navigation . To do this, move back and forth until you can see two fixed points exactly one behind the other. For example two towers or two beacons . Then you are exactly on a line extending these points. The position is more accurate the further the two points are apart or the closer you are to the front point. Because you don't need a measuring device for the deck bearing and because no conversion from a magnetic to a true bearing is required, two sources of error are eliminated.
Leading lights are used in shipping at night . During the day, directional beacons or other striking objects whose position is marked on the map help . This is used to mark port entrances or passages between shallows , for example . As long as both objects are "in cover", you are on a straight line that runs from the bank towards the fairway.
In order to keep to the line - or the part of a fairway defined by it - two markings, beacons or triangular top signs placed one behind the other must be kept "in cover". The triangles sit on beacons and point to each other with their tips. As a result, the accuracy of this simple bearing is much higher than with a compass, for example .
With a further stand line you can now determine your own location precisely. For example with a cross bearing, i.e. when a third object is exactly abeam (at right angles to the line of the deck bearing). This second baseline is more precise the closer the third object is to the baseline.
A deck bearing and a baseline from a compass bearing is more accurate than two compass bearings.
See also: leading lights , alignment (surveying) , cross bearing , standing bearing , lateral system
literature
- Kurt Graf, Dietrich Steinicke: The official sports boat license lake. Delius Klasing Verlag, Bielefeld 2012, ISBN 978-3-7688-3486-5 .