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Geographical parallels

The location in the geographical sense is your own position on the earth's surface or in a suitable geometric reference system . Semantically synonymous are terms such as standpoint , own position or topocenter (from the Greek topos for place), to which other terms from various scientific disciplines come. The determination of the location is often referred to as localization or location determination . In particular, time , speed and direction can be viewed as part of location data.

The location is not only important for your own orientation , but is also the (local) zero point of the so-called topocentric coordinate system for measurements . In a broader sense - for example in astronomy or space travel - the location can also be on other celestial bodies .


A location can be specified in a number of different ways, including:

Absolute and relative location information

Absolute information

The following coordinate systems can be considered absolute:

Relative information

The bird watchers could indicate their location relative to the river and the nearest bridge

Relative location information is more common in everyday life and for location reports that are unprepared. In the case of urgency ( accident , imminent danger), the reliability of the location report in terms of clarity is important, but also accessibility in the transport network.

A relative specification can be related to

  • a street or an object
    • Address (house number, object)
    • Distance from an intersection
    • Direction and distance from a prominent building
  • Traffic routes, bodies of water, details in the area
    • Mileage (milestone, river kilometers)
    • Distance from a prominent structure
    • in the great outdoors: peaks, mountainsides, forest edges

Examples of directions:

  • "In the extension from A to B"
  • "Towards 9 o'clock" (= west)
  • "Approx. a hand's breadth to the right of the parish church "(A hand's breadth on the outstretched arm of the observer covers an angle of ~ 10 °.)

Conversion of relative information

Most of the relative locations can be converted to absolute, for example

For the accuracy of location information

To find a point again, the necessary accuracy depends on the task at hand. While at reports of incidents or accidents, the uniqueness of the Location is important, must at measuring the accuracy of the position information approximately the measurement accuracy correspond.

Examples of accuracies

The value of an observation or measurement at an outdoor location usually also depends on the reliability of the location information. For observations in the wild, a location at around 100 m is usually appropriate, as is easily possible with a map .

The accuracies can be very different for technical and scientific tasks.

  • Terrestrial targets depending on distance: measurement accuracy (in degrees) × distance / 57.3. As an example : an event in 10 km, direction estimated at 10 ° → 1.7 km (1 km location is sufficient).
  • Measurement of boundary points in an alpine pasture area : Meter accuracy is sufficient if the cadastral plan only has a scale of 1: 2880 or 1: 5000.
  • Measurement of a sewer if the height reference to the community is required: millimeters to centimeters.
  • Astronomical angle measurements to ± 1 ″ → location information to at least ± 30 m (corresponds to 1 ″ from the center of the earth).
  • A bright meteor (ball of fire), direction of 5 ° recorded (in the constellation XY) → location at least 5 km (a glowing meteor is 50–100 km away).

Methods for accurate terrestrial location information

In the case of higher demands, the method also depends on the purpose and the object to be measured.

Exact positions are usually specified in a coordinate system that relates to a defined reference point or zero point. The most important of these systems are based on complex measurements, but are therefore an absolute, permanent frame of reference.


  • Heribert Kahmen : surveying , 19th edition, published by De Gruyter.
  • Axel Bark : Sailing license , 9th edition, Bielefeld 1982.
  • Thomas Glatte : Development of operational real estate - Procurement & utilization of real estate in corporate real estate management , Springer Vieweg, Wiesbaden 2014, ISBN 978-3-658-05686-5
  • Brockhaus (6 volumes), Wiesbaden 1959–1961.

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