# Location

The orientation of an object to the surrounding space is referred to as spatial position , especially with regard to the horizontal or the plumb direction .

A complete specification also includes its direction and sometimes also the height .

The spatial position in the above horizon system is primarily determined by our equilibrium organ, but supported by the eye and the muscular sense . However, the sense of balance can be disturbed by unusual movements or postures (e.g. vertigo ). It is more reliable with a spirit level or the artificial horizon on an airplane . Precise measurements use special plumbing sensors or vials for leveling .

Rotational movements are controlled through the semicircular canals in the inner ear, when flying instruments with the turn pointer . North-related directions are mainly measured with a magnetic compass ; for exact geodetic measurements see below.

## Tilt

The angle between the base (or the longitudinal axis ) of a body and the local horizon is called the slope or inclination . In aircraft , this angle (rotation around the transverse axis) is called pitching , while the angle of rotation around the longitudinal axis is called roll .

In the case of machine axes , one speaks of axis inclination , in the case of non-horizontal terrain of incline or slope inclination , in the case of changing heights of traffic routes of the gradient . In geology, the spatial position of rock strata and fissures is determined by measuring the angle of fall and strike . In geotechnics , these elements are represented on the so-called layer sphere , which in mathematics corresponds to a directional or unit sphere .

While in everyday life one relates the spatial position to the horizontal or to a flat surface of the earth , in astronomy separate definitions are necessary. The position of a satellite orbit is related to the plane of the earth's equator and is referred to as orbital inclination.

## direction

In addition to the inclination of an object or an axis to the horizon, the spatial position also includes its orientation relative to the north , especially when the object (or person) is moving. This direction is commonly referred to as the compass direction , in science and technology mostly as the azimuth .

In navigation one speaks of course , which can refer to geographic or magnetic north . In English it is called Course or track ( course over ground ) or as Heading ( heading refers).

## Geodesy and Geography

In the earth sciences - depending on the task - several coordinate systems are in use:

## Astronomy and space travel

In a weightless room there is no natural reference to a perpendicular direction . Therefore, the spatial position is determined here with regard to astronomically defined directions and planes: