Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. Mike ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
I don't think you can infer OS methodology from comparison of OS and Bing photographs of rivers. Rivers are not static objects - they move laterally over time, unless confined by concrete, in towns etc. In the countryside they will migrate backwards and forwards by possibly many hundreds of metres over a few decades. Compare parish boundaries with Bing imagery, you'll see inexplicable bulges in the line, where they diverge from rivers, and then rejoin downstream. PHILLIP BARNETT SERVER MANAGER 200 GRAY'S INN ROAD LONDON WC1X 8XZ UNITED KINGDOM T +44 (0)20 7430 4474 F E phillip.barn...@itn.co.uk WWW.ITN.CO.UK Please consider the environment. Do you really need to print this email? -Original Message- From: Michael Collinson [mailto:m...@ayeltd.biz] Sent: 09 March 2011 11:57 To: 'Talk GB' Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. Mike ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb Please Note: Any views or opinions are solely those of the author and do not necessarily represent those of Independent Television News Limited unless specifically stated. This email and any files attached are confidential and intended solely for the use of the individual or entity to which they are addressed. If you have received this email in error, please notify postmas...@itn.co.uk Please note that to ensure regulatory compliance and for the protection of our clients and business, we may monitor and read messages sent to and from our systems. Thank You. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On 09/03/2011 11:57, Michael Collinson wrote: At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. Mike ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb Interesting point Mike. There are similar issues about tracing from imagery or using Vector Map District when doing other waterbodies: reservoirs are the ones which immediately come to mind. Often the landward side of the splash zone is more obvious than the usual water level, and if that is used for mapping it gives a false impression. Patches of riparian scrub and marsh also seem to be treated inconsistently by the OS (perhaps aerial interpretation). Most larger rivers will have flood-level gauges (right word?) which might be some kind of aid for choosing a 'natural' level to map, but sourcing then is not straightforward. I've only done a bit of mapping by wandering around in wellies with one foot on dry land and the other in the water. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
At 13:29 09/03/2011, Chris Hill wrote: On 09/03/11 11:57, Michael Collinson wrote: At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. A further word of caution: Bing and all other imagery only shows a snapshot of the way things are, often many years ago, and in an indeterminate state of water level. Some rivers have tidal influences, some rivers have very different levels in flood or drought. Sometimes where the rough verge meets pasture land is the highest point the water reaches regularly, but still only occasionally. Certainly both Chris' and Phillip's cautions are certainly true but I've paid particular attention to the River Wharfe mid-reaches, which I know very well and flows in a well-defined channel with high banks and has not shifted markedly in the last 40 years. In places, it is almost twice as wide as it should be. Chris may be right in suggesting that the highest water mark is being mapped, but why map the 10 - 25-year flood event level rather than the natural bank line? I am tempted to think that automated software has been used which like PGS coastlines occasionally gets confused by nearby lineaments. I also recall comparing with digitised 25:000 maps (vintage 1900 - 1960 surveying) and noticing that it correlates much more closely with Bing than StreetView. Needs more analysis but be aware! Mike ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Hi Mike, Can you provide us with a grid ref(s) for a location where the OS data is wrong Jason On 9 March 2011 13:33, Michael Collinson m...@ayeltd.biz wrote: At 13:29 09/03/2011, Chris Hill wrote: On 09/03/11 11:57, Michael Collinson wrote: At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. A further word of caution: Bing and all other imagery only shows a snapshot of the way things are, often many years ago, and in an indeterminate state of water level. Some rivers have tidal influences, some rivers have very different levels in flood or drought. Sometimes where the rough verge meets pasture land is the highest point the water reaches regularly, but still only occasionally. Certainly both Chris' and Phillip's cautions are certainly true but I've paid particular attention to the River Wharfe mid-reaches, which I know very well and flows in a well-defined channel with high banks and has not shifted markedly in the last 40 years. In places, it is almost twice as wide as it should be. Chris may be right in suggesting that the highest water mark is being mapped, but why map the 10 - 25-year flood event level rather than the natural bank line? I am tempted to think that automated software has been used which like PGS coastlines occasionally gets confused by nearby lineaments. I also recall comparing with digitised 25:000 maps (vintage 1900 - 1960 surveying) and noticing that it correlates much more closely with Bing than StreetView. Needs more analysis but be aware! Mike ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Jason, Yes, I'll try to do this over the weekend. Give me an off-line poke if I forget. Mike At 14:45 09/03/2011, Jason Cunningham wrote: Hi Mike, Can you provide us with a grid ref(s) for a location where the OS data is wrong Jason On 9 March 2011 13:33, Michael Collinson mailto:m...@ayeltd.bizm...@ayeltd.biz wrote: At 13:29 09/03/2011, Chris Hill wrote: On 09/03/11 11:57, Michael Collinson wrote: At 12:32 10/02/2011, Andy Robinson (blackadder-lists) wrote: Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. A late response to this thread, but a word of caution. Comparing Bing imagery recently for several Yorkshire rivers with folk's riverbanks derived from OS data indicates that very frequently the OS are not tracing the riverbank as the dividing line between water (clear river channel) and land (grass, scrub) but the top of the riverbank or where the rough verge meets pasture land. A further word of caution: Bing and all other imagery only shows a snapshot of the way things are, often many years ago, and in an indeterminate state of water level. Some rivers have tidal influences, some rivers have very different levels in flood or drought. Sometimes where the rough verge meets pasture land is the highest point the water reaches regularly, but still only occasionally. Certainly both Chris' and Phillip's cautions are certainly true but I've paid particular attention to the River Wharfe mid-reaches, which I know very well and flows in a well-defined channel with high banks and has not shifted markedly in the last 40 years. In places, it is almost twice as wide as it should be. Chris may be right in suggesting that the highest water mark is being mapped, but why map the 10 - 25-year flood event level rather than the natural bank line? I am tempted to think that automated software has been used which like PGS coastlines occasionally gets confused by nearby lineaments. I also recall comparing with digitised 25:000 maps (vintage 1900 - 1960 surveying) and noticing that it correlates much more closely with Bing than StreetView. Needs more analysis but be aware! Mike ___ Talk-GB mailing list mailto:Talk-GB@openstreetmap.orgTalk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On 9 February 2011 18:42, Jason Cunningham jamicu...@googlemail.com wrote: OS VectorMap District is an excellent source of data for features like streams and woodland, but these layers of data tend to be a bit of a mess and need to be stitched together as part of a method in importing into OSM. eg Streams will end when they meet a bridge, then reappear the other side of the bridge, so for OSM you need to link all the separate sections of the streams into one long stream Started to notice that the VectroMap District data in its raw state has started to appear in the map, from more than one mapper http://osm.org/go/erduA_U9K-- http://osm.org/go/eugeBnUca- You can see stream are broken presumably at locations of bridges, and woodland has strips missing presumably along paths (and is also made up of several sections if you look at it in an editor) Doesn't appear to be guidance in the wiki about how to deal with VectorMap District. I just want to check I'm right in thinking this is the wrong way to go about it? If so I'll try and write up some guidance in the wiki. I do agree that raw water features from OS Vector District are pretty unsatisfactory and should be cleaned up. Personally I would prefer a single linear way for streams rather than the area 'river-bank' approach which the OS use, however the most important thing is for water features to be continuous under bridges. I support people putting guidance together but won't contribute myself to a great extent. On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. Regards, Peter Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: Personally I would prefer a single linear way for streams rather than the area 'river-bank' approach which the OS use The 'river-bank' approach has been exceptionally useful to me at times when trying to micro-navigate. Why would it ever be better to have less information? Cheers, Henry ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On 10 February 2011 10:35, Henry Gomersall h...@cantab.net wrote: On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: Personally I would prefer a single linear way for streams rather than the area 'river-bank' approach which the OS use The 'river-bank' approach has been exceptionally useful to me at times when trying to micro-navigate. Why would it ever be better to have less information? Agreed. I think that was my conclusion by the end of my post. I should probably have removed the early bit before pressing send! Apologies. Peter Cheers, Henry ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Peter Miller wrote: however the most important thing is for water features to be continuous under bridges Absolutely. Otherwise some of OSM's resident under-bridge-dwellers might be misled into thinking there was no water, fall in and drown. And we wouldn't want that! cheers Richard -- View this message in context: http://gis.638310.n2.nabble.com/Incorrect-use-of-OS-VectorMap-District-when-mapping-tp6009028p6011210.html Sent from the Great Britain mailing list archive at Nabble.com. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Hi, On 02/10/11 11:35, Henry Gomersall wrote: On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: Personally I would prefer a single linear way for streams rather than the area 'river-bank' approach which the OS use The 'river-bank' approach has been exceptionally useful to me at times when trying to micro-navigate. Why would it ever be better to have less information? This is not an either-or decision; many people map riverbanks for appearance plus a waterway=river way through the centre. Among other things, this gives one the chance to map the direction of water flow. (In theory, such a line could be computed but that's something of a black art; http://ageoguy.blogspot.com/2010/12/squelettisation.html for interesting details - and I sure as hell don't want to have to set up a machine to do that for the whole planet on a daily basis...) Bye Frederik ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On 10/02/2011 10:30, Peter Miller wrote: Personally I would prefer a single linear way for streams rather than the area 'river-bank' approach which the OS use... Ideally it should be mapped with both: http://wiki.openstreetmap.org/wiki/Tag:waterway%3Driverbank Cheers Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Henry Gomersall [mailto:h...@cantab.net] wrote: Sent: 10 February 2011 11:07 AM To: Peter Miller Cc: Talk GB Subject: Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping? On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. Cheers Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On 09/02/2011 20:27, Kevin Peat wrote: Hi Jason, I am the mapper (user:devonshire) who imported the woods in your first example around Dartmouth but it was last May so not exactly recently. The woods that are there now are a lot better than the NPE traced ones that we had before. I took the view at the time that importing the VectorMap data would be a major improvement. Since the Bing imagery (old as it is) became available I am not sure why anyone would bother importing VectorMap woods as it is a lot less hassle to trace from Bing and just take the names from the OS StreetView. Ultimately I will probably replace the OS sourced data but it isn't a big priority for me right now. Feel free if you have nothing better to do. The VectorMap data for streams is good especially as they are virtually impossible to survey well on the ground. Filling in the blanks may seem like a good idea but whether it is a track bridging the stream, the stream is piped or just disappears for a bit (as often happens in wetland areas) is hard to know without a survey. Kevin On 9 February 2011 18:42, Jason Cunningham jamicu...@googlemail.com mailto:jamicu...@googlemail.com wrote: OS VectorMap District is an excellent source of data for features like streams and woodland, but these layers of data tend to be a bit of a mess and need to be stitched together as part of a method in importing into OSM. eg Streams will end when they meet a bridge, then reappear the other side of the bridge, so for OSM you need to link all the separate sections of the streams into one long stream Started to notice that the VectroMap District data in its raw state has started to appear in the map, from more than one mapper http://osm.org/go/erduA_U9K-- http://osm.org/go/eugeBnUca- You can see stream are broken presumably at locations of bridges, and woodland has strips missing presumably along paths (and is also made up of several sections if you look at it in an editor) Doesn't appear to be guidance in the wiki about how to deal with VectorMap District. I just want to check I'm right in thinking this is the wrong way to go about it? If so I'll try and write up some guidance in the wiki. Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org mailto:Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb Jason has pointed out a number of issues with the natural features layer of VectorMap District. I'd like to add a few more: * Larger Streams Rivers are only present as areas, not vectors, as well as not being connected. Absence of vector waterway data, particularly when not connected, means that OSM data is useless for any kind of hydrographic or hydrological analysis. Old traced streams from NPE maps on the other hand are still fit for this purpose. Use case: low cost simulation of environmental issues (water pollution, flooding) for charities, campaign groups etc. * Woodland parcels can be incredibly minute and over detailed: to an extent that the detail cannot be verified on the ground. * Woodland parcels are often not woodland. So far I have found parkland with interspersed trees (see any golf course), small groups of trees with no corresponding ground layer (not a wood, see first example posted by Jason), wetland features http://www.flickr.com/photos/sk53_osm/4611517582 (exuberant over-interpretation of aerial images), avenues of trees, suburban and urban parks where one or two old specimen trees have large spreads, scrub... * Woodland parcels are often separated by a short distance to provide for a path, even when the canopy is closed. * Many areas are artificially divided by lines corresponding to the 1 kilometer lines of the National Grid. The main problem is that although VDM shapes are often extremely detailed, in many cases the accuracy and detail is spurious. Another problem is that adding areas of streams or many woodland fragments places a significant burden on a) servers; b) editors and c) consumers (see Frederik's post). I like having these things on the map, but I do want to be able to have maps on the Garmin which cover a useful area. Thus adding this kind of detail may mean thinking either about adding new tags or extending existing tagging in the way which is happening with buildings. Personally, I might start trying to use natural=tree on areas and ways so that some of these 'woodland' categories can be separated out: an obvious render approach is like that used by the OSGB for 'scattered trees'. Note that there are vector waterways and woodland available in the OS OpenData set which might be
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
On Thu, 2011-02-10 at 11:32 +, Andy Robinson (blackadder-lists) wrote: On Thu, 2011-02-10 at 10:30 +, Peter Miller wrote: On reflection possibly we should use river-bank as that has more information in it, but recommend that anyone importing does a 'bridge cleanup' at the same time. This is an area I'm actually really interested in (for rural rivers) and keen to contribute. So far I've been put off by exactly this problem. Is a reasonable approach to use the OS data for river edges and then fill in the gaps (bridges etc) with OSM data? +1 If the OS vector data is only assumed to be the banks and the additional data for flow direction, bridges and other features are added from survey/BING etc then we should end up with a very functional dataset. Further to this point, what happens when there is a river with a tarn inline? For example: http://osm.org/go/evO4TBvG Should there be a continuous flow direction through the tarn? cheers, Henry ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Incorrect use of OS VectorMap District when mapping?
OS VectorMap District is an excellent source of data for features like streams and woodland, but these layers of data tend to be a bit of a mess and need to be stitched together as part of a method in importing into OSM. eg Streams will end when they meet a bridge, then reappear the other side of the bridge, so for OSM you need to link all the separate sections of the streams into one long stream Started to notice that the VectroMap District data in its raw state has started to appear in the map, from more than one mapper http://osm.org/go/erduA_U9K-- http://osm.org/go/eugeBnUca- You can see stream are broken presumably at locations of bridges, and woodland has strips missing presumably along paths (and is also made up of several sections if you look at it in an editor) Doesn't appear to be guidance in the wiki about how to deal with VectorMap District. I just want to check I'm right in thinking this is the wrong way to go about it? If so I'll try and write up some guidance in the wiki. Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Incorrect use of OS VectorMap District when mapping?
Hi Jason, I am the mapper (user:devonshire) who imported the woods in your first example around Dartmouth but it was last May so not exactly recently. The woods that are there now are a lot better than the NPE traced ones that we had before. I took the view at the time that importing the VectorMap data would be a major improvement. Since the Bing imagery (old as it is) became available I am not sure why anyone would bother importing VectorMap woods as it is a lot less hassle to trace from Bing and just take the names from the OS StreetView. Ultimately I will probably replace the OS sourced data but it isn't a big priority for me right now. Feel free if you have nothing better to do. The VectorMap data for streams is good especially as they are virtually impossible to survey well on the ground. Filling in the blanks may seem like a good idea but whether it is a track bridging the stream, the stream is piped or just disappears for a bit (as often happens in wetland areas) is hard to know without a survey. Kevin On 9 February 2011 18:42, Jason Cunningham jamicu...@googlemail.com wrote: OS VectorMap District is an excellent source of data for features like streams and woodland, but these layers of data tend to be a bit of a mess and need to be stitched together as part of a method in importing into OSM. eg Streams will end when they meet a bridge, then reappear the other side of the bridge, so for OSM you need to link all the separate sections of the streams into one long stream Started to notice that the VectroMap District data in its raw state has started to appear in the map, from more than one mapper http://osm.org/go/erduA_U9K-- http://osm.org/go/eugeBnUca- You can see stream are broken presumably at locations of bridges, and woodland has strips missing presumably along paths (and is also made up of several sections if you look at it in an editor) Doesn't appear to be guidance in the wiki about how to deal with VectorMap District. I just want to check I'm right in thinking this is the wrong way to go about it? If so I'll try and write up some guidance in the wiki. Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
