The direction can depend on the current movement or your own position (e.g. left and right , up, down, straight ahead), in relation to an object or another location (e.g. in the direction of the mountain, in the direction of Hamburg) or in relation to the earth's axis ( north , east , south , west ).
In geodesy , direction is the value read on the horizontal circle after a point has been sighted with the telescopic sight of a theodolite. A horizontal angle is calculated from the difference between two directions (right minus left reading), i.e. H. the two directions form the legs of an angle.
In sound engineering , directional hearing of phantom sound sources on the stereo basis between the loudspeakers and also in natural hearing is not referred to as location , but rather as localization .
For measurement of direction , different instruments.
Directional designations in aviation and shipping
In aviation and shipping, a clear distinction must always be made as to whether a directional information refers to the current direction of the vehicle (so-called lateral bearing , relative direction) or is absolute. Absolute courses are compass courses given based on true north. Since the compass does not point to geographic but to magnetic north, the course must be corrected beforehand by taking the declination and any deviation into account. According to this calculation, z. For example, the skipper instructs the helmsman to take the course zero-five-zero , which he then steers in such a way that this new course can be read on the steering compass. The ship then points with its nose in the desired direction, measured from true north.
In addition to this absolute direction indication with a compass course, there are various ways of indicating a relative direction. This is the deviation from the ship's steering direction, also measured in degrees (e.g. with a bearing disc or radar). Both are not always available and are often cumbersome to use. The great accuracy of Seitenpeilung in degrees is also often not required, it is sufficient if the lookout reports obstacle port forward or buoy abeam , is thus given only the approximate direction of the object. The advantage of this information is that it cannot be confused with an absolute directional information and therefore fatal misunderstandings between lookout and helmsman or navigator and helmsman are avoided.
The following nautical designations are used as relative directions: ahead (in front of the ship), aft (behind the ship), to port, to starboard, abeam. Occasionally, directions are also defined with the positions on an imaginary dial . At 12 o'clock means straight ahead , at 1 o'clock then right / starboard ahead etc.