Tag:man_made=survey_point

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Public-images-osm logo.svg man_made = survey_point
Trig Point near Wootton Wawen.jpg
Description
A triangulation pillar, geodetic vertex, or other piece of fixed equipment used by topographers. Edit or translate this description.
Group: Man made
Used on these elements
may be used on nodesshould not be used on waysshould not be used on areasshould not be used on relations
Useful combination
Status: approvedPage for proposal

Wikidata

A  survey point is a triangulation pillar, geodetic vertex, or other piece of fixed equipment used by topographers. These points are normally in a fixed location and of a known altitude used for old-fashioned surveying.

How to map

Add a node node at the location of the trig point, tagged with man_made=survey_point.

It can be combined with the following generic tags: name=*, ele=*, ref=*, operator=*, description=*.

There are also three tags specific to survey markers: survey_point:structure=*, survey_point:datum_aligned=*, survey_point:purpose=*. See the tables below.

Structure

Tag Description Example
survey_point:structure=beacon A large structure, typically four-legged, visible from a far distance. Sometimes called a Trig Station.

Common in Australia and New Zealand.


Can be combined with height=* to describe the height of the trig station (usually 2 to 4 metres).

survey_point:structure=block A solid block that sits on the ground, generally on a small concrete foundation.
survey_point:structure=pillar A pillar - generally smaller and more slender than a block.
survey_point:structure=pole A pole is much more slender and generally taller than a pillar.

In the photo, there are two poles. The shorter pole in the foreground is also a valid example of a pole

survey_point:structure=bracket A plaque-like bracket that allows equipment to be hooked into it.

If you cannot hook equipment into it, then it is a plaque (see below)

A bracket
survey_point:structure=plaque If there is only a plaque, and no other structure.

Use bracket (see above) if the plaque allows you to connect survey equipment.

A plaque next to a geodetic survey marker (circled in red)
survey_point:structure=medallion Circular plate embedded at the surface of a larger structure, typically a building. Survey instruments may be inserted in it for measures. A french general levelling levelling survey point, medallion shape
survey_point:structure=pin If there is no physical structure, besides from the pin/bolt itself. See also: indented_pin


In the photo, the pin has a circle spray-painted around it. This does not count as a structure.

A pin in the surface of a road, used as a geodetic survey marker
survey_point:structure=indented_pin Similar to pin, except that it has an indent for inserting survey equipment An indented pin
survey_point:structure=cut A line cut into a wall or rock A line cut into the side of a brick wall
survey_point:structure=magnet If the survey marker is an underground magnet. Please combine with location=underground Example

Condition

Tag Description
survey_point:datum_aligned=yes If the location of the marker is known to be reliably aligned to the nearest  Geodetic datum.
survey_point:datum_aligned=no If the location of the marker is NOT aligned to the local  Geodetic datum.

This may be because of an earthquake/landslide/flood, or it was moved accidently, or moved by growing tree roots.

Purpose

Tag Description
survey_point:purpose=horizontal Often called a  Triangulation Point, this is used in geodetic surveys to measure horizontal distance between objects.
survey_point:purpose=vertical Often called a  Benchmark. Used to measure difference in elevation.
survey_point:purpose=both If a marker can be used for both horizontal and vertical triangulation

Notes

  • If a survey marker has been destroyed, you may replace man_made=survey_point with destroyed:man_made=survey_point if you really want to map it, but keep in mind Good practice.
  • If a survey marker still exists but is no longer visible, you could add location=underground. For marks embedded into the roadway, resealing the road may have covered the pin. Another example is if a building was constructed on top of the marker.

Rendering

Survey points are currently not rendered in openstreetmap-carto.

Man made survey point.svg suggested by User:Chrisana13

Possible Tagging Mistakes

If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!
If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!
If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!
If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!