Tag:man_made=survey_point
 man_made = survey_point
|
 |
| Description |
|---|
A triangulation pillar, geodetic vertex, or other piece of fixed equipment used by topographers. 
|
| Group: Man made |
| Used on these elements |
    |
| Useful combination |
Status: approved
|
| Tools for this tag |
|
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 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.
|
|
| 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=pillar | Taller than it is wide, commonly designed for surveying equipment to be placed directly onto the top of the pillar. | 
|
| survey_point:structure=block | A man-made block built into ground, with top of block often at ground level, or up to approximately 0.5m from ground level. | 
|
| 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) |
|
| 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. |
|
| 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. | 
|
| survey_point:structure=pin | If there is no physical structure, besides from the pin/bolt itself. See also: indented_pin
|
|
| survey_point:structure=indented_pin | Similar to pin, except that it has an indent for inserting survey equipment | 
|
| survey_point:structure=cut | A line cut into a wall or rock | 
|
| 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.
suggested by User:Chrisana13