Re: [Tagging] Feature proposal - RFC - natural=ridge
Kytömaa Lauri wrote: Unfortunately that srtm data ends at 60° N: http://osm.org/go/0TORO-- Actually it ends at 61° N, with the last 1° block starting at 60° N. For some reason the cylce map no longer uses that last block. And it's eventually way too scarse. Right. -- Arne Johannessen ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Nathan Edgars II wrote: On 11/8/2011 2:03 PM, John F. Eldredge wrote: Nathan Edgars IInerou...@gmail.com wrote: What I mean is that if the ridges can be auto-generated, they can be rendered without being in the database. They can't be auto-generated from gridded DEMs. Consider these neighboured elevation grid points as an example: 200 213 ? 210 196 It's impossible to tell if the altitude in the centre is more like 212 (creating a SW-NE ridge) or more like 198 (creating a saddle with a NW-SE mountain pass). In any event, the ridges created from such gridded data would have a jagged zigzag form which would neither be correct nor pleasing to the eye. As far as DEMs go, you need additional data besides grid or spot elevations to fully represent the terrain. This includes skeleton lines (ridges and streams) and cliffs. Since we map streams and cliffs as a matter of course, there's no reason not to do the same with ridges. The main problem really is getting an exact position for those features. Might be rather difficult in many cases (incorrect Bing imagery in mountainous terrain, dangerous cliffs prevent you from surveying by GPS, ...). What data source are you suggesting that the renderer should use, if not the OSM database? The same one that the cycle map layer uses to draw contour lines. As Lauri already noted, those are too coarse to be of much use for skeleton lines in large scales (beyond zoom level 10 or so). Regards, Arne -- Arne Johannessen ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
What data source are you suggesting that the renderer should use, if not the OSM database? The same one that the cycle map layer uses to draw contour lines. Unfortunately that srtm data ends at 60° N: http://osm.org/go/0TORO-- And it's eventually way too scarse. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
2011/11/7 Dmitri Lebedev siberia.acca...@gmail.com: Hello, this is the page with the proposal: http://wiki.openstreetmap.org/wiki/Proposed_features/ridge Just look at this picture: http://upload.wikimedia.org/wikipedia/commons/thumb/e/e0/North_Ridge_of_Mount_Rohr.jpg/400px-North_Ridge_of_Mount_Rohr.jpg There are peaks that can be tagged properly (although it's technically possible to deduct them with some accuracy from elevation maps), but between them there are ridges, the top edges of the mountains. I like this proposal, because it is truly important to have these connections in a map (you will usually see them in the elevation isolines, but they might have a name) I am not sure for the wording though. Isn't this an edge? Maybe I am confused, because wikipedia told me that a ridge would be a natural feature (your proposal doesn't give any definition what a ridge is) occuring at a _chain of mountains_ (but in the osm wiki you also speak about hills) while for shorter places I found http://en.wikipedia.org/wiki/Ar%C3%AAte (french words do IMHO not really make sense) and http://en.wikipedia.org/wiki/Spur_(topography), crest and edge (could also be that interlanguage links are not precise, I am mostly referring to the difference between de:Gebirgskamm and de:Grat). Is this all the same? Shall we distinct between them? I think due to the various words in use for features of this kind a definition should be given and alternatives proposed for features that are close but excluded by this definition. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
2011/11/8 John Sturdy jcg.stu...@gmail.com: I think it's easier to survey a ridge (either from aerials, or by walking along it with GPS) than to get enough altitude points to generate it automatically, so I think we should allow them to be entered as ways (which won't prevent renderers from finding more ridges from altitude points). +1, they are also often important connections for hikers (will have additional highway=path tag). I don't see the point why we shouldn't map them. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
2011/11/8 Martin Koppenhoefer dieterdre...@gmail.com I am not sure for the wording though. Isn't this an edge? Maybe I am confused, because wikipedia told me that a ridge would be a natural feature (your proposal doesn't give any definition what a ridge is) occuring at a _chain of mountains_ (but in the osm wiki you also speak about hills) while for shorter places I found http://en.wikipedia.org/wiki/Ar%C3%AAte (french words do IMHO not really make sense) and http://en.wikipedia.org/wiki/Spur_(topography), crest and edge (could also be that interlanguage links are not precise, I am mostly referring to the difference between de:Gebirgskamm and de:Grat). Looking at Wikipedia I can follow your point. But I think this is more due the language links. I think ridge is the common term which encompasses both German terms Grat and Gebirgskamm. Here some articles from Wikipedia that should show their common use: * http://en.wikipedia.org/wiki/Crib_Goch - especially legend of map * http://en.wikipedia.org/wiki/Mount_Everest#Southeast_ridge Also interesting is the definition of Arête as a kind of ridge in Merriam-Webster: http://www.merriam-webster.com/dictionary/arete Is this all the same? Shall we distinct between them? Basically I think we shouldn't. I think due to the various words in use for features of this kind a definition should be given and alternatives proposed for features that are close but excluded by this definition. This would definetly help - especially for us Germans trying to understand the difference :-) Here a picture of what I personally would consider a ridge: http://upload.wikimedia.org/wikipedia/commons/d/d6/Herzogstand_HQ.jpg Michael ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Martin, Ridge IMO closest means Kamm in German. eg. Nordkette north of Innsbruck http://de.wikipedia.org/wiki/Inntalkette (German) - we should distinguish this from - a whole mountain range (das Gebirge in German) eg. http://en.wikipedia.org/wiki/Steinernes_Meer http://en.wikipedia.org/wiki/Tennengebirge http://en.wikipedia.org/wiki/Berchtesgaden_Alps http://en.wikipedia.org/wiki/Kitzb%C3%BChel_Alps http://en.wikipedia.org/wiki/Dolomites ... or even bigger (Gebirgszug or Gebirgszugsystem): http://en.wikipedia.org/wiki/Northern_Limestone_Alps (other mountain ranges are named there) = natural=ridge (Gebirgskamm) (mapped as a way) vs natural=range or mountain_range (Gebirge or Gebirgszug) (mapped as an area) /al ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
2011/11/8 Andreas Labres l...@lab.at: Ridge IMO closest means Kamm in German. yes, I'd also see it like this. So how would you tag a de:Grat? natural=edge? - we should distinguish this from - a whole mountain range (das Gebirge in German) natural=range or mountain_range (Gebirge or Gebirgszug) (mapped as an area) not sure if we should map them at all. Mapping geographical features as big as those is usually not an OSM domain (we do this is no field: we don't map oceans and seas, we don't map landscapes, valleys and mountain ranges, ... Our data model, processing and db organisation is not very suited to handle this kind of stuff. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Hi Martin, 2011/11/8 Martin Koppenhoefer dieterdre...@gmail.com Yes, that's unambigous, but what about this? Thanks, that's what I tried . 1 http://www.rainerundclaudia.de/wp-content/uploads/2009/07/20090419-Mit-Julia-u.-Alex-am-Karlsruher-Grat-0232.jpg 2 http://alpinestock.com/grat_sareiserjoch_malbun_liechtenstein_sjpg1883.jpg I would consider both a ridge. But honestly my personal definition would be to the German Grat...:-) To give a negative example, here something I would not consider a ridge but either cliff or rock: http://upload.wikimedia.org/wikipedia/commons/8/8d/H%C3%B6rnleLochenstein.jpg More seriously: I would suggest to use ridge for the distinct feature. A could extend (more or less) horizontally like the image I've referenced before. There I would claim that a ridge at maximum extends from one peak to another. There are also ridges more vertically oriented and separating the slopes of a mountain. So basically a ridge is a feature of one or two mountains only. I think we all agree, that a continental divide or the Alpenhauptkamm are not ridges. They these large scale features will very likely contain many ridges but also other features. This is probably like the distiction between cliff and coast. Mapping mountain ranges IMO is a different story, more related to mapping large features (e.g. valleys like the Great Rift Valley). To my point of view this is already adequatly covered in the proposal. Also I just came across the region proposal: http://wiki.openstreetmap.org/wiki/Relations/Proposed/Region Michael ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
2011/11/8 Michael Krämer ohr...@googlemail.com: I would consider both a ridge. But honestly my personal definition would be to the German Grat...:-) To give a negative example, here something I would not consider a ridge but either cliff or rock: http://upload.wikimedia.org/wikipedia/commons/8/8d/H%C3%B6rnleLochenstein.jpg +1, it's all about age ;-), I'd tag the steep parts natural=cliff. More seriously: I would suggest to use ridge for the distinct feature. ... So basically a ridge is a feature of one or two mountains only. not sure, from what I read a ridge can probably span between several mountains (or hills). it can also form a crest? As you wrote, you are thinking about a de:Grat for which I agree it does not extend over the summit of a mountain (while a Kamm will, it consists of several Grat). I think we all agree, that a continental divide or the Alpenhauptkamm are not ridges. They these large scale features will very likely contain many ridges but also other features. well, Hauptkamm (main .) does also imply sub-objects. We could make relations type=route, route=ridge (or mountain_ridge or mountain_range,) containing each other. With relations we could also map similar geographic features like gorges without additional geometry: we put the adjacent cliffs in a relation, e.g. type=area, and tag the relation with natural=gorge, name=xy so you'd know that the feature is between these ways. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
On 08.11.11 16:26, Martin Koppenhoefer wrote: So how would you tag a de:Grat? Don't know what the correct English phrase would be. Maybe the mountain guys @talk-at know... User fkv/0/ has done a lot of mountain edits, AFAICT. BTW, should also be discussed rendering-wise, comparing a cliff (where it goes down on one side) vs the Grat (where it goes down on both sides). /al /0/ http://osm.org/go/0JookMGyY-- ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Nathan Edgars II nerou...@gmail.com wrote: On 11/7/2011 5:41 PM, Dmitri Lebedev wrote: Is a ridge something that can be auto-generated from good elevationdata? If so, probably only named ridges need to be mapped. I think it's ok to map unnamed ridges, just to show that some borders go by them. Also, on a flat map without elevation lines, but with semi-transparent overlay imitating shadows, peaks connected together will make more sense. Right now, look at any mountaineous region, the peaks just stick out chaotically. I think it's worth connecting them together. What I mean is that if the ridges can be auto-generated, they can be rendered without being in the database. What data source are you suggesting that the renderer should use, if not the OSM database? -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Dmitri Lebedev siberia.accanto@... writes: Hello, this is the page with the proposal: http://wiki.openstreetmap.org/wiki/Proposed_features/ridge There are peaks that can be tagged properly (although it's technically possible to deduct them with some accuracy from elevation maps), but between them there are ridges, the top edges of the mountains. Those are not peaks, they descend from or ascend to another peak. And a ridge is an important object. Very good proposal, a ridge is absolutely something for a map. I guess these kind of natural objects of the geography was on the very first maps in the world. /Johan Jönsson ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
On 11/7/2011 5:41 PM, Dmitri Lebedev wrote: Is a ridge something that can be auto-generated from good elevationdata? If so, probably only named ridges need to be mapped. I think it's ok to map unnamed ridges, just to show that some borders go by them. Also, on a flat map without elevation lines, but with semi-transparent overlay imitating shadows, peaks connected together will make more sense. Right now, look at any mountaineous region, the peaks just stick out chaotically. I think it's worth connecting them together. What I mean is that if the ridges can be auto-generated, they can be rendered without being in the database. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
Nathan Edgars II nerou...@gmail.com wrote: On 11/7/2011 5:41 PM, Dmitri Lebedev wrote: Is a ridge something that can be auto-generated from good elevationdata? If so, probably only named ridges need to be mapped. I think it's ok to map unnamed ridges, just to show that some borders by them. Also, on a flat map without elevation lines, but with semi-transparent overlay imitating shadows, peaks connected together will make more sense. Right now, look at any mountaineous region, the peaks just stick out chaotically. I think it's worth connecting them together. What I mean is that if the ridges can be auto-generated, they can be rendered without being in the database. If you don't have the longitude, latitude, and altitude of a sufficient number of points in the database, any calculated ridge-lines are likely to have little resemblance to reality. This isn't magic, you know. -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
On 11/7/2011 10:11 PM, John F. Eldredge wrote: If you don't have the longitude, latitude, and altitude of a sufficient number of points in the database, any calculated ridge-lines are likely to have little resemblance to reality. This isn't magic, you know. I know. The cycle map layer uses this information to draw contour lines. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature proposal - RFC - natural=ridge
On 11/8/11, John F. Eldredge j...@jfeldredge.com wrote: What I mean is that if the ridges can be auto-generated, they can be rendered without being in the database. If you don't have the longitude, latitude, and altitude of a sufficient number of points in the database, any calculated ridge-lines are likely to have little resemblance to reality. This isn't magic, you know. I think it's easier to survey a ridge (either from aerials, or by walking along it with GPS) than to get enough altitude points to generate it automatically, so I think we should allow them to be entered as ways (which won't prevent renderers from finding more ridges from altitude points). __John ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
