Re: [Tagging] Survey points
2015-03-11 16:51 GMT+01:00 Malcolm Herring malcolm.herr...@btinternet.com: This is why I am of the view that survey points should be mapped on separate nodes. I agree, having an area tagged as survey point doesn't make much sense, it will be a precise point, typically marked with a metal sign similar to this: http://www.pitopia.de/pictures/standard/f/focusfinder/91/focusfinder_402591.jpg cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015 14:43, moltonel 3x Combo wrote: Adding a separate survey_point node would have little benefit. The problem in many cases is the man_made key. I come across many objects that were tagged man_made=lighthouse, with other tags describing attributes of that structure, but then another mapper has come along and added the man_made=survey_point tag, that replaces the original tag. Often URL and other reference tags get overwritten as well. This is why I am of the view that survey points should be mapped on separate nodes. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 12/03/2015 1:43 AM, moltonel 3x Combo wrote: Here is a fine example of this case : http://www.openstreetmap.org/way/236843122 The description tag explains that the reference point is the base of the christian cross on this bell tower. I think it makes sense of mapping this this way : in a sense the whole building *is* the man_made=survey_point. Adding a separate survey_point node would have little benefit. There are other examples like this one, but not all of them have a neat description of where the precise survey point is on the structure. On the other hand, some ways look a bit pointless and could probably be nodes, but a survey is needed to be sure: True 'survey points' are documented with their precise location, date of location and description. So looking at that data would clarify the situation and not require a visit. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
OK, the mapper in question did not reply, but silently removed the tags. This leaves me none the wiser as to the more widespread usage of this tag. Looking closer at the data, it appears that man_made=survey_point is very often added to prominent objects, particularly towers, masts and lighthouses. Could it be that some survey agencies use these objects as triangulation points? If so, it raises a couple of issues: 1. The man_made key should refer to the structure, not its usage. 2. The drift towards micro-mapping means that such objects, originally mapped as nodes, get converted to plan outlines and the tags moved to that closed way. If the intent of the survey_point mapper was to set a lat/lon positional reference, then that scheme is undone. Might it not be appropriate to add a note in the Wiki page for this tag that it should not be added it to existing objects, but to always create a separate node? ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015 10:23, Malcolm Herring wrote: On 11/03/2015 09:46, moltonel 3x Combo wrote: Care to review them ? I took a quick look at these objects the few that I examined were actually created as areas, rather than had been converted from a node. The most egregious example is this one: http://www.openstreetmap.org/way/199650922. It is a square with sides over 500m, and a note that reads do not move this node!!?? Looking at the edit, that's more likely to be a just newbie faux pas isn't it? The do not move this node stuff is used regularly for French survey points. May this is the survey point: https://www.openstreetmap.org/node/2096332697 Perhaps a changeset discussion comment or OSM note might be the way forward? Cheers, Andy ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015, Malcolm Herring malcolm.herr...@btinternet.com wrote: I took a quick look at these objects the few that I examined were actually created as areas, rather than had been converted from a node. The most egregious example is this one: http://www.openstreetmap.org/way/199650922. It is a square with sides over 500m, and a note that reads do not move this node!!?? Fixed. See http://www.openstreetmap.org/node/670609313/history which was part of the way and is the original proper survey point. Luckily the point was not moved (just got its tags deleted) and was retained as part of the way. The contributor probably used the replace geometry action from utilsplugin2. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015, Malcolm Herring malcolm.herr...@btinternet.com wrote: OK, the mapper in question did not reply, but silently removed the tags. This leaves me none the wiser as to the more widespread usage of this tag. At least that's reassurance that a buoy, which can drift quite a bit on the surface, isn't considered as a survey point :p Looking closer at the data, it appears that man_made=survey_point is very often added to prominent objects, particularly towers, masts and lighthouses. Could it be that some survey agencies use these objects as triangulation points? Often yes. And to make that survey point official when it isn't a purpose-built structure, there is often a reference plaque placed on the structure at the exact location of the point. If so, it raises a couple of issues: 1. The man_made key should refer to the structure, not its usage. 2. The drift towards micro-mapping means that such objects, originally mapped as nodes, get converted to plan outlines and the tags moved to that closed way. If the intent of the survey_point mapper was to set a lat/lon positional reference, then that scheme is undone. Might it not be appropriate to add a note in the Wiki page for this tag that it should not be added it to existing objects, but to always create a separate node? The wiki already mentions that the tag only applies to nodes, which should in theory catch upgraded to an area mishapps. There are currently 64 survey_point ways in the db (compared to 287000 nodes), so the problem exists but isn't too big. Care to review them ? That said, a always add survey points as their own node recommendation on the wiki can't hurt. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
A survey point is those brass markers in the ground - an official X in the ground of some kind. I assume a tower on a distant mountain is a survey_reference_object or similar. It certainly isn't a point. Javbw On Mar 11, 2015, at 5:46 PM, Malcolm Herring malcolm.herr...@btinternet.com wrote: OK, the mapper in question did not reply, but silently removed the tags. This leaves me none the wiser as to the more widespread usage of this tag. Looking closer at the data, it appears that man_made=survey_point is very often added to prominent objects, particularly towers, masts and lighthouses. Could it be that some survey agencies use these objects as triangulation points? If so, it raises a couple of issues: 1. The man_made key should refer to the structure, not its usage. 2. The drift towards micro-mapping means that such objects, originally mapped as nodes, get converted to plan outlines and the tags moved to that closed way. If the intent of the survey_point mapper was to set a lat/lon positional reference, then that scheme is undone. Might it not be appropriate to add a note in the Wiki page for this tag that it should not be added it to existing objects, but to always create a separate node? ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015 11:57, Martin Koppenhoefer wrote: maybe the tower has a point defined (e.g. top of the antenna or a sign or similar) which could be a survey_point. Since surveyors have to take bearings-from as well as bearings-to survey points, the point would have to be located where survey instruments can be set up. One would expect, therefore, that these points would be at ground level. That is how the Wiki illustrates them. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
2015-03-11 12:49 GMT+01:00 John Willis jo...@mac.com: I assume a tower on a distant mountain is a survey_reference_object or similar. It certainly isn't a point. maybe the tower has a point defined (e.g. top of the antenna or a sign or similar) which could be a survey_point. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 11/03/2015, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2015-03-11 12:49 GMT+01:00 John Willis jo...@mac.com: I assume a tower on a distant mountain is a survey_reference_object or similar. It certainly isn't a point. maybe the tower has a point defined (e.g. top of the antenna or a sign or similar) which could be a survey_point. Here is a fine example of this case : http://www.openstreetmap.org/way/236843122 The description tag explains that the reference point is the base of the christian cross on this bell tower. I think it makes sense of mapping this this way : in a sense the whole building *is* the man_made=survey_point. Adding a separate survey_point node would have little benefit. There are other examples like this one, but not all of them have a neat description of where the precise survey point is on the structure. On the other hand, some ways look a bit pointless and could probably be nodes, but a survey is needed to be sure: http://www.openstreetmap.org/way/4041174 http://www.openstreetmap.org/way/315474577 ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Survey points
On 10/03/2015 8:02 AM, Malcolm Herring wrote: The Wiki is very clear (in several languages) as what a survey point is, but is there some other meaning that mappers understand this term to mean? The reason I ask is that I often come across man_made=survey_point tags that have been added to other objects. Not infrequently this tag replaces an existing man_made=* tag, even though other tags describing the original object remain. This then creates a nonsensical set of tags. I have just come across these tags added to some buoys in the middle of the River Maas! As is often the case, the changeset was un-commented, so I have added a query comment to see if I can discover what was in that mappers mind. Send the mapper a message - through | www.openstreetmap.org/user/[user_name] That way you may learn of what was meant? | ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
