The course angle (also direction angle , in Switzerland azimuth or artillery promille or English azimuth ) is a term from navigation and describes the angle between north direction and target direction. It is always given starting from north in a clockwise direction . For example, if you move directly to the east, the course angle is 90 ° or 1600 lines . The specific numerical value of the course angle depends on the angle unit used, e.g. B. Example degree , graduation , line .
If 100 lines are used as the angle unit (90 ° then corresponds to 16 units), the course angle is also called the march number , march direction number or compass number , etc. Ä.
Finding a heading number with the compass from the map
- The compass edge applied at the line from start to finish.
- Turn the compass rose so that its north-south line coincides with the map north / grid north .
- Read off the direction of march on the front sight (direction arrow, line of sight).
Running according to the marching direction number
- Bring the marching direction number on the compass by turning the compass rose in line with the front sight (direction arrow, line of sight).
- Hold the compass level at eye level and adjust the mirror so that the needle can be checked. Align the needle with the north marking.
- Aim over the rear sight and front sight and track down and note a prominent point in the sight line.
- Walk in the direction of the prominent point in the area.
Point A has the coordinates ( ),
Point B has the coordinates ( ).
is positive for latitudes in the northern hemisphere and negative in the southern hemisphere; to the east is positive, to the west is negative.
Then applies to the course angle :
with the restriction that only an angle in the range 0 °… 180 ° is calculated. There is no distinction in which quadrant the course lies.
Where is the spherical distance on the unit sphere between A and B, which results from
(To calculate the orthodromic length, see here .)
When it is the spherical distance e on the unit sphere, expressed in radians, see Spherical geometry, distance .
If the starting point, the course angle and the route length are known, the target coordinates can also be calculated with this formula.