Talk:Tag:man made=survey point

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Different types of survey points

How to make a difference between different types of survey points? International nautical maps use 4 different symbols depending if the survey point is a triangulation point, observation point, fixed point, or a benchmark. (see INT 1 B20 - B23) --Skippern 09:03, 3 May 2011 (BST)

I see you added these to the page as type=*. That is recommended to be avoided (see Key:type) as it can be confusing or difficult to understand. For this case, it would be better to use either survey_point=* or survey_point:type=* --Neuhausr (talk) 12:57, 8 July 2015 (UTC)

Some hunting cabins have been mapped as observation points. I suppose this is incorrect ? What is an observation point ?

trig station vs survey mark

The wiki page for man_made=survey_point describes it for trig stations, but how can we map survey points which are just a small circular disk cemented into the ground? Aharvey (talk) 01:52, 16 November 2017 (UTC)

The wiki page states 'benchmarks' too, these are not trig stations. It would be useful to distinguish between the two. The key height could give some idea of the situation, height=0 for surface marks? survey_point=benchmark/triangulation_station, benchmark:material=brass or survey_point:material=brass ??? Warin61 (talk) 23:54, 19 November 2017 (UTC)
I would also support the proposal of the additional survey_point=triangulation_station/benchmark/flush_bracket keys as they would be most useful. --DrMxy (talk) 14:06, 3 July 2018 (UTC)
The definition is "survey point is a triangulation pillar, geodetic vertex, or other piece of fixed equipment" so that includes all survey marks. If you look back through the history of this page various people have tried adding sub classes only to have their work removed. Seamarks does have a tag to indicate the sub class Seamarks/Categories_of_Objects#Control Points (CATCTR) Adavidson (talk) 08:57, 20 November 2017 (UTC)
I find encouragement that others have felt the need for sub tags. Perhaps survey_point:category=benchmark/triangulation/* with good definitions would gain use/approval? Triangulation would be something visible at distance (over 1 km), benchmark would be close to surface level. Warin61 (talk) 21:52, 20 November 2017 (UTC)

tag ref=* its bracket number

On the main page the ref=* it has been stated to use 'its bracket number'. I assume this is some regional reference system used in some areas of the world. I think that stating it this way will lead to other areas of the world not using it for their reference system =- thus OSM will loose that data. The statement might be better stated as "for example use the bracket number as provided in the USA." Warin61 (talk) 22:06, 31 July 2018 (UTC)


Other properties

What about defining a survey_point:order or survey_point:level subtag for the importance of a point? It can be 3 for 3rd level, etc. One may also specify whether it is a main point at a given level.

Is this "level" or "order" something that is marked on the survey point objects in your area? If so, then it is verifiable and you could add it. It must be an objective characteristic of the survey point. But I don't think survey markers in the USA include anything like this, so we wouldn't be able to use this tag in our country. --Jeisenbe (talk) 02:28, 14 March 2020 (UTC)
Usually the 'level' of 'order' is related to the accuracy of the information, and would be contained in the documentation of the location together with the relevant date, etc etc. It may be publicly available, certainly available to professional surveyors. I don't think you will find it on the actual sight, certainly not in my area of the world. Warin61 (talk) 07:12, 14 March 2020 (UTC)
There is a public list of base survey points in my country. I'll tag the data sheet URL for each POI. On the field, though, it's not so clear: Even a 3rd level point may have massive protection if needed, and there is a 1st level point without any covers. It would help the surveyors, like finding the closest high-level point. ITineris (talk) 08:14, 14 March 2020 (UTC)

The tagging could indicate whether the survey point is a GNSS base reference point, like survey_point:gnss_base=yes. ITineris (talk) 13:51, 13 March 2020 (UTC)

This could be indicated by the physical properties enabling the mounting of a professional GPS antenna? The tagging could provide for different things and gain better use if more universal, say survey_point:function=gnss_base and possibly survey_point:form=gps_antenna_mount ??? Warin61 (talk) 07:18, 14 March 2020 (UTC)
No, the laymen won't recognize if it's a GNSS reference point. It's only the official categorisation. Only gravimetric bases have a different appearance - again, below the protection, hidden from the visitors. ITineris (talk) 08:14, 14 March 2020 (UTC)

Agency / Operator

Survey points may say:

  1. Fish and Wildlife board survey marker "Lifeland #21".
  2. Fillburg County highway department marker "HY 21 #W32".
  3. Nurdsburg Township office department of levels, marker "N'brg TWP #13".
  4. Thailand National Boundary Commission point "TH-MM #432".
  5. Phapburg City Plan, point #ABC3.
  6. Narfburg Property Bureau "PROP #77".
  7. Pfitzburg Military Reserve "Fine $1000 #21".
  8. Vietnam China joint boundary treaty commission marker #0.

etc. So there should be a standard field saying who is responsible, separate from the "name" and "ref". Jidanni (talk) 21:55, 1 August 2019 (UTC)

Suggest using the existing key operator=* as that is what it is intended for. Warin61 (talk) 03:16, 2 August 2019 (UTC)

Examples

I would like to add some more examples of common types of survey point one might see when mapping.

Survey points are often marked in the center line of new streets, at intersections and wherever the curvature of the street changes. Making a note of them can help a mapper draw the shape of the street more accurately.

Comments and additional examples are welcome.

T99 (talk) 08:58, 16 February 2020 (UTC)

Picture Tags Description
Aerial-marker.jpg

man_made=survey_point

survey_point=aerial

ref=9316

A survey marker designed to be seen clearly in aerial photography.

Cotton-spindle-spike.jpg

man_made=survey_point

survey_point=spindle

An old cotton picker spindle reused as a survey marker.

Temporary-marker.jpg

man_made=survey_point

survey_point=bar

ref=8013

A simple survey point, a metal bar or spike driven into the ground. This one was temporary and was shortly replaced by a monument in a well.

Monument-well-construction.jpg

construction:man_made=survey_point

survey_point=monument

A monument well (a sturdy hollow cylinder made to protect a permanent survey monument inside). This one is still under construction.

Monument-well-finished.jpg

man_made=survey_point

survey_point=monument

Another monument well (a sturdy hollow cylinder made to protect a permanent survey monument inside). This one has just been finished.

Geo1.jpg

man_made=survey_point

survey_point=geodetic_tower

A geodetic tower. Typically a tubular concrete tower above, or close next to, the survey point that makes better observation possible.

Geo2.jpg

man_made=survey_point

survey_point=prism

A prism above the survey point. Typically a wooden structure.

man_made=survey_point

survey_point=tripod

A steel tripod above the survey point.

Geo3.jpg

man_made=survey_point

survey_point=frustrum

An underground monument protected by a square frustum shaped concrete upper part filled with soil.

Geo4.jpg

man_made=survey_point

survey_point=?

A concrete column sunk into the ground, with a metal pin or an etched X mark on its top.

Geo5.jpg

man_made=survey_point

survey_point=?

A concrete slab above a monument

Geo6.jpg

man_made=survey_point

survey_point=steel_pipe

A vertical steel pipe or column

Geo7.jpg

man_made=survey_point

survey_point=table

Cast iron table with X etched into the surface

Geo8.jpg

man_made=survey_point

survey_point=?

Steel rod driven into the ground, with a hard plastic heading

Geo9.jpg

man_made=survey_point

survey_point=metal_plate

Metal plate above a monument

Geo10.jpg

man_made=survey_point

survey_point=pin

Various metal pins, typically driven into a pavement.

Geo11.jpg

man_made=survey_point

survey_point=benchmark

A (vertical) benchmark. Q: How to distinguish from the sentinels of a horizontal survey point?

Rebar-marker-painted.jpg

man_made=survey_point

survey_point=rebar

ele=315.732 ft

A simple metal bar or spike (here apparently rebar) driven into the center line of the street is common when a monument well is not required. This one has a big white dot painted around it for visibility (thank you, City of Rocklin) and has an accurate elevation reading as a bonus.

Boundary-marker-capped.jpg

boundary=marker

material=metal

This point has obviously been surveyed accurately but it is used to mark the boundary between two residential lots. That makes it a boundary marker. The engraving on the metal plate probably identifies the land surveyor or the project as it did not vary from lot to lot in this case.

Mapping at this level of detail is usually not necessary.

The above demonstrates why survey_point=* is not good. It is being used for several different things at once. The function e.g. survey_point=benchmark and the physical form e.g. survey_point=pin. These should be separate tags. Consider, for example, survey_point:function=benchmark and survey_point:form=pin. Note: There is a proposal for benchmark presently being discussed on the tagging list. See https://wiki.openstreetmap.org/wiki/Proposed_features/survey_point:benchmark Warin61 (talk) 21:12, 13 March 2020 (UTC)