Re: [OSM-talk] source=Google
On Tue, May 21, 2013 at 9:26 PM, Martin Koppenhoefer dieterdre...@gmail.com wrote: What do you propose to do with source tags found on an object when you modify this object based on a different source? Speaking for myself, I either replace it (if I'm replacing virtually all the geometry) or supplement it: source=gps;Bing. If I'm tweaking something that had no source before, I sometimes use source=unknown;Bing. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On 18/05/2013 16:56, Martin Koppenhoefer wrote: Point is it doesn't really belong in the data, because it is metadata. This is a false argument. There's nothing wrong with metadata in the database if it's *useful*. When I go for a walk I survey. I use a gps. When mapping the data I use Bing imagery to confirm where I went add details I couldn't fully see like hedges etc. I then use the internet to search for names of shops places that I forgot. All different sources within one changeset edit. Dave F. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
2013/5/21 Dave F. dave...@madasafish.com On 18/05/2013 16:56, Martin Koppenhoefer wrote: Point is it doesn't really belong in the data, because it is metadata. This is a false argument. There's nothing wrong with metadata in the database if it's *useful*. When I go for a walk I survey. I use a gps. When mapping the data I use Bing imagery to confirm where I went add details I couldn't fully see like hedges etc. I then use the internet to search for names of shops places that I forgot. All different sources within one changeset edit. Yes, you could either split your edits into similar edits (useful IMHO, as it introduces some logical system into the way you perform uploads) or combine the sources into something like survey and tracing from bing aerial imagery and websearch IMHO it is useful to a) know from when the aerial imagery was you traced from b) know whether the mapper knew the area or only traced from aerial imagery c) know whether the mapping was based on a recent survey d) know in particular cases like import from supposedly precise sources (e.g. cadastre) where the data was taken from e) know the reason when an object gets modified or deleted (e.g. the pub was closed) f) know the source of hard to survey real world objects (e.g. undersea cables, underground stuff) g) store the source of data that requires some kind of attribution But in the end I think this whole source thing is completely overestimated. In the end the following mappers will compare what is on the map with what they know or believe to be there in reality, and in case of discrepancies will probably modify the map based on their findings, regardless of any source tag. What do you propose to do with source tags found on an object when you modify this object based on a different source? cheers, Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Martin Koppenhoefer wrote: But in the end I think this whole source thing is completely overestimated. Yup. What do you propose to do with source tags found on an object when you modify this object based on a different source? OSM has full object history. :) cheers Richard -- View this message in context: http://gis.19327.n5.nabble.com/source-Google-tp5761629p5762025.html Sent from the General Discussion mailing list archive at Nabble.com. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On Tue, May 21, 2013 at 1:26 PM, Martin Koppenhoefer dieterdre...@gmail.com wrote: But in the end I think this whole source thing is completely overestimated. In the end the following mappers will compare what is on the map with what they know or believe to be there in reality, and in case of discrepancies will probably modify the map based on their findings, regardless of any source tag. +1 if during a survey, you notice something different than what is in OSM, you change it, no matter what's the source. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Hi, maybe a little bit. For remote-mappers it's a good hint, if objects doesn't fit to imagery. Henning Am 21.05.2013 13:26, schrieb Martin Koppenhoefer: But in the end I think this whole source thing is completely overestimated. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Am 21.05.2013 13:30, schrieb Richard Fairhurst: Martin Koppenhoefer wrote: What do you propose to do with source tags found on an object when you modify this object based on a different source? OSM has full object history. :) ...which is an argument that the source may fit well on the changeset, too (while that's only true for changesets that rely on one source only). regards Peter ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[OSM-talk] source=Google
There are abot 33.000 objects in OSM which have google in the one way or another in their source tag: http://malenki.ch/d/2013-05-18_142122_scr_source_google.png Just type google in the value-field: http://taginfo.openstreetmap.org/keys/source#values Any thoughts about that? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
http://wiki.openstreetmap.org/wiki/WikiProject_Haiti/Imagery_and_data_sources#Google_Imagery This is one explanation. Also source=Google really says nothing that source is Google Maps. P. 2013/5/18 malenki o...@malenki.ch There are abot 33.000 objects in OSM which have google in the one way or another in their source tag: http://malenki.ch/d/2013-05-18_142122_scr_source_google.png Just type google in the value-field: http://taginfo.openstreetmap.org/keys/source#values Any thoughts about that? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk -- mortigi tempo Pēteris Krišjānis ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
2013/5/18 malenki o...@malenki.ch Any thoughts about that? don't put source tags on objects but on the changeset? If you are interested what the intended meaning is, you should ask the contributors who added this, I guess different mappers used this for different things, google is quite generic. cheers, Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On 18/05/13 13:31, malenki wrote: There are abot 33.000 objects in OSM which have google in the one way or another in their source tag: http://malenki.ch/d/2013-05-18_142122_scr_source_google.png Just type google in the value-field: http://taginfo.openstreetmap.org/keys/source#values Any thoughts about that? Recently I asked a new contributor to the area I routinely check about the fact that he had tagged source=google on a changeset for some paths he had added. It turned out that he had legitimately traced Bing imagery, but he had assumed it was Google - the only imagery he was familiar with. This is now burned into the history, forever giving the wrong impression. My take on this is that _all_ of these dubious sources need investigating with the original editors. Any real transgressions should be redacted, but expect some genuine errors as I found. These need marking or recording to show they are not worth investigating again in the future. -- Cheers, Chris user: chillly ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Martin Koppenhoefer wrote: 2013/5/18 malenki o...@malenki.ch Any thoughts about that? don't put source tags on objects but on the changeset? I see no difference in using source= on objects or changesets except the visibility for the source ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
pec...@gmail.com wrote: http://wiki.openstreetmap.org/wiki/WikiProject_Haiti/Imagery_and_data_sources#Google_Imagery This is one explanation. As it seems for the value parts with the matching dates on them. Also source=Google really says nothing that source is Google Maps. hopefully ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On 18/05/2013 13:31, malenki wrote: There are abot 33.000 objects in OSM which have google in the one way or another in their source tag: http://malenki.ch/d/2013-05-18_142122_scr_source_google.png Just type google in the value-field: http://taginfo.openstreetmap.org/keys/source#values Any thoughts about that? I use Google daily to map in OSM. I search their database for names websites of schools, restaurants etc. Nothing wrong in that. I don't tag the source as google, but others might. IMO Source should be on the object, not on the changeset. Dave F. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Dave F. wrote: I use Google daily to map in OSM. I search their database for names websites of schools, restaurants etc. Nothing wrong in that. I don't tag the source as google, but others might. Since Google links to websites of the schools, restaurants etc I'd consider it wrong to say google is the source. One could also say source=internet or source=brain. :) IMO Source should be on the object, not on the changeset. +1 (except if there is one changeset for one object (; ) ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On 05/18/2013 03:55 PM, malenki wrote: Dave F. wrote: IMO Source should be on the object, not on the changeset. +1 (except if there is one changeset for one object (; ) This is not my opinion. Let's take a simple example: a school. Some first user maps it from imagery, and so just draws the building. So we have something like: building=yes source=Bing Now someone who went on the place add the fact that this building is a school. So we have something like: building=yes amenity=school name=Ecole de la Vie source=Bing;survey Now, the public administration release an open data file with many informations on every schools. Someone takes this info and add it to our school. So we have now, for example: building=yes amenity=school name=Ecole de la vie capacity=1800 wheelchair=yes addr:street=Rue de la Vie addr:housenumber=42 source=? Now, we have the opportunity to fly a drone on the area, and so we have a very accurate imagery, which is great. So someone goes on our building way and move it a little bit, change a little bit the shape to better follow the reality, etc. So the question is: now, what should be the source tag value? And which of every attributes or geo informations is covered by this value? My personal answer is that the source should be on the changeset, which is where the data comes from. Yohan ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Yohan Boniface wrote: On 05/18/2013 03:55 PM, malenki wrote: Dave F. wrote: IMO Source should be on the object, not on the changeset. +1 (except if there is one changeset for one object (; ) This is not my opinion. Let's take a simple example: a school. Some first user maps it from imagery, and so just draws the building. So we have something like: building=yes source=Bing there is source:outline=* http://taginfo.osm.org/keys/source%3Aoutline (used 10150 times so far) Now someone who went on the place add the fact that this building is a school. So we have something like: building=yes amenity=school name=Ecole de la Vie source=Bing;survey source=survey - since it has been surveyed Now, the public administration release an open data file with many informations on every schools. Someone takes this info and add it to our school. So we have now, for example: building=yes amenity=school name=Ecole de la vie capacity=1800 wheelchair=yes addr:street=Rue de la Vie addr:housenumber=42 source=? there is source:addr= http://taginfo.osm.org/keys/source%3Aaddr (used 2015605 times so far) Now, we have the opportunity to fly a drone on the area, and so we have a very accurate imagery, which is great. So someone goes on our building way and move it a little bit, change a little bit the shape to better follow the reality, etc. change source:outline So the question is: now, what should be the source tag value? And which of every attributes or geo informations is covered by this value? My personal answer is that the source should be on the changeset, which is where the data comes from. Mine you see above. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
2013/5/18 malenki o...@malenki.ch Martin Koppenhoefer wrote: 2013/5/18 malenki o...@malenki.ch Any thoughts about that? don't put source tags on objects but on the changeset? I see no difference in using source= on objects or changesets except the visibility for the source Point is it doesn't really belong in the data, because it is metadata. What would you say if people tagged reason=why I did this edit on the objects? Similar thing but maybe more obvious. The source is only refering to the edit when the tag is added. The next mapper changing some property with a different source (e.g. knowledge) has then to decide how to deal with this source tag, and there really is no satisfying option to do so. cheers, Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
Anybody else who noticed we already had this discussion last year ;) http://lists.openstreetmap.org/pipermail/talk/2012-November/065034.html On 05/18/2013 02:31 PM, malenki wrote: There are abot 33.000 objects in OSM which have google in the one way or another in their source tag: http://malenki.ch/d/2013-05-18_142122_scr_source_google.png Just type google in the value-field: http://taginfo.openstreetmap.org/keys/source#values Any thoughts about that? --- m.v.g., Cartinus ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On Saturday 18 May 2013, Yohan Boniface wrote: On 05/18/2013 03:55 PM, malenki wrote: Dave F. wrote: IMO Source should be on the object, not on the changeset. +1 (except if there is one changeset for one object (; ) This is not my opinion. Let's take a simple example: a school. [...] The problem is currently neither changeset nor object tags are really a good solution for true metadata (that is information characterizing the data and not the real world object). Changeset tags have mainly two problems: - they always apply to the whole changeset so everything you map together needs to have the same metadata. This might seem to be a problem primarily for imports but it can also be troublesome in manual mapping - imagine mapping something based on satellite images and you need to use different images for various parts due to clouds or even the common case of supplementing survey data with Bing images. - many large objects are included in a lot of changesets without actually being substantially modified (like moving a single node in a 500 node way etc.) This means finding the actual changeset a certain geometry originates from to get the metadata information is not so easy. The solution in my opinion would be to have separate metadata tags which are reset everytime a substantial change is made to the data they refer to unless the user explicitly sets them (either individually or for the whole changeset). Geometry metadata tags for example would be reset if: - in case of a node the node is moved - in case of a way more than X percent of the nodes are changed (X being something like 30) - in case of a multipolygon more than X percent of the ways are added/removed or substantially modified This would not be fool proof of course (small changes could accumulate to a substantial change without being noticed). Greetings, -- Christoph Hormann http://www.imagico.de/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
I will point out here that iD has invented a new changeset tag which I find useful. It automatically records what imagery layers you use while editing and throws them into an imagery_used=* tag. This removes the need for users to manually tag source information if they are just tracing imagery. I wouldn't mind seeing other editors adopt this convention. Toby On Sat, May 18, 2013 at 11:12 AM, Christoph Hormann chris_horm...@gmx.dewrote: On Saturday 18 May 2013, Yohan Boniface wrote: On 05/18/2013 03:55 PM, malenki wrote: Dave F. wrote: IMO Source should be on the object, not on the changeset. +1 (except if there is one changeset for one object (; ) This is not my opinion. Let's take a simple example: a school. [...] The problem is currently neither changeset nor object tags are really a good solution for true metadata (that is information characterizing the data and not the real world object). Changeset tags have mainly two problems: - they always apply to the whole changeset so everything you map together needs to have the same metadata. This might seem to be a problem primarily for imports but it can also be troublesome in manual mapping - imagine mapping something based on satellite images and you need to use different images for various parts due to clouds or even the common case of supplementing survey data with Bing images. - many large objects are included in a lot of changesets without actually being substantially modified (like moving a single node in a 500 node way etc.) This means finding the actual changeset a certain geometry originates from to get the metadata information is not so easy. The solution in my opinion would be to have separate metadata tags which are reset everytime a substantial change is made to the data they refer to unless the user explicitly sets them (either individually or for the whole changeset). Geometry metadata tags for example would be reset if: - in case of a node the node is moved - in case of a way more than X percent of the nodes are changed (X being something like 30) - in case of a multipolygon more than X percent of the ways are added/removed or substantially modified This would not be fool proof of course (small changes could accumulate to a substantial change without being noticed). Greetings, -- Christoph Hormann http://www.imagico.de/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
2013/5/18 Christoph Hormann chris_horm...@gmx.de - imagine mapping something based on satellite images and you need to use different images for various parts due to clouds or even the common case of supplementing survey data with Bing images. yes, this is very common, at least in regions with alternative high resolution imagery, but it is similar for object and for changeset source tags. For instance bing alone doesn't tell you which zoom level you used, but different (high) zoom levels in Bing are based on different aerial imagery (in my area there are years if not a decade in between z20 and z21 and they also have different offsets). I almost always use at least 2 aerial imagery providers (pcn and bing), drawing in one and positioning in the other, in the comment I simply write ...and tracing from PCN2008 and bing. Usually with aerial imagery from webmaps you also don't see from when they are, at least almost nobody stores this information in the source tag, but it is much more relevant (IMHO) to know traced from aerial imagery from 2007 than traced from bing aerials In the end it is almost pointless to compare different aerial imagery layers with each other, what matters is reality and the best way to find out is leave your desk and go out mapping ;-) - many large objects are included in a lot of changesets without actually being substantially modified (like moving a single node in a 500 node way etc.) This means finding the actual changeset a certain geometry originates from to get the metadata information is not so easy. you will see from the changeset that only one node was moved (added or deleted) and this will supposedly be based on your specified source, generally moving a node will not create a new way version, but I get what you intended (e.g. add or delete a node). IMHO this is a point for associating the source to the changeset, as modifying it on the object after adding this one node will tell the wrong story but not modifying the source tag is neither desirable. The solution in my opinion would be to have separate metadata tags which are reset everytime a substantial change is made to the data they refer to unless the user explicitly sets them (either individually or for the whole changeset). Geometry metadata tags for example would be reset if: Your mention of geometry metadata reminds me of another point: a simple source is not enough, you'd need a distinct source tag for all properties not one source for the whole object. cheers, Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] source=Google
On Saturday 18 May 2013, Martin Koppenhoefer wrote: [...] Usually with aerial imagery from webmaps you also don't see from when they are, at least almost nobody stores this information in the source tag, but it is much more relevant (IMHO) to know traced from aerial imagery from 2007 than traced from bing aerials Much agreed, date of the images is much more relevant than the provider. The lack of this information in Bing etc. combined with the fact that first hand survey information is usually entered shortly after the survey has lead to a lack of practical need for entering this information. Your mention of geometry metadata reminds me of another point: a simple source is not enough, you'd need a distinct source tag for all properties not one source for the whole object. I already had that in mind - i just explained it for the geometry only. Each tag could have its own metadata and this would be reset everytime the tag value is changed. And of course in addition to 'source' one could think of various other metadata types. The date is obvious but accuracy as well as reliability information could also be useful metadata. -- Christoph Hormann http://www.imagico.de/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
