Azimuth Word that comes from the Arabic “as-sumut” (direction or zenith ). It has certain meanings according to its use.
Summary
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- 1 Astronomy
- 1 Topography and cartography
- 2 Nautical or navigation
- 3 Instruments
- 2 Sources
Astronomy
It is the angle or longitude of arc measured on the celestial horizon that form the cardinal point North or South and the vertical projection of the star on the horizon of the observer located in some latitude North (South). It is measured in degrees from the cardinal point clockwise from the clock : North – East – South – West .
Topography and cartography
Azimuth is the angle of a direction counted clockwise from the geographic north. The azimuth of a point to the east is 90 degrees and to the west 270 sexagesimal degrees. The term is only used when it comes to geographic north. When you start counting from magnetic north, it is usually called the bearing or magnetic azimuth. In geodesy or geodetic topography the azimuth is used to determine the orientation of a triangulation system .
In cartography and especially in topography, azimuths are often expressed in hundredths degrees instead of using sexagesimal degrees.
Nautical or navigation
In nautical, the azimuth is measured from the north cardinal point clockwise from 0 ° to 360 ° and is called true azimuth (Azv) or real. The magnetic azimuth, if measured from magnetic north (Azm) or compass azimuth (Azc), if measured from the north point of the compass . In the case of air navigation charts , in which the magnetic azimuth is used, it is called heading.
Instruments
The taking of horizontal angles in the marine vocabulary is usually called “marking”. On ships, “visual markings” are taken from gimbal-suspended platforms that have a rotating (alidated) ring called taximeters. On ships equipped with a gyro compass, taximeters usually have a gyro “repeater”, which allows the “azimuth compass” to be taken directly, to which the known error, if any, must be added.
A “radar marking” may also be taken at the identified echoes. If the radar is in “relative” presentation, that is to say that its “line of faith” is indicating the bow, to that “delay” is added the course. If the radar is in “true” display, the faith line indicates North and the azimuth is taken directly.
