Re: [Talk-GB] “Correcting” existing data wi th OS Opendata
This was me, but I know that Paul Sladen, Simon Halsey, and probably others, were also affected. Has anyone has sent the offending user a message? He/she is a relative newcomer, and has edited in Trowbridge as well as Carlton/Gedling. They have also edited in Germany, but no indication of traces or on-the-ground surveys. Some of my GPS ways unfortunately also had fixme=location approximate, which was probably as a result of over use of copying tags from one way to another. This may have invited editing, but other 'corrections' have been made so that now many streets are slightly misaligned from GPS traces. I, and I would guess other active contributors around Nottingham, have been avoiding using StreetView and Locator other than to add names on stuff mapped from aerial images. In particular the Carlton/Gedling area is one which my personal preference was to leave the current status as is until ground surveys were done. Obviously other contributors have different preferences, time-scales, needs etc., so I recognise that this might not be possible. I would hope thought that some contact with active local mappers would be made before bulk in-fill with StreetView or similar sources, particularly as it cannot have escaped their attention that this was possible. Last Summer I mapped a tiny part of Middlesbrough over 2.5 hours. When StreetView became available an area about 25 times larger was mapped in a similar timescale. The 'productivity' difference is so huge that a single armchair mapper can swamp contributions from people doing ground survey. On the other hand, places like Oldham, Rochdale, Darlington, Middlesbrough are now so much more usable in OSM. So we still have the trade-off between usability of the map data, contributor 'happiness', mapping from an armchair versus on-the-ground. The use of StreetView exemplifies all these issues. Jerry From: Simon Ward si...@bleah.co.uk To: talk-gb@openstreetmap.org Sent: Sun, 18 July, 2010 13:54:30 Subject: [Talk-GB] “Correcting” existing data with OS Opendata I just added a comment to the talk page about OS Opendata[1]: It seems that some people have been using OS Opendata to “correct” existing data, moving ways to match OS Opendata, and in some cases removing attributes (such as surface=paved). Please, please, please, pretty please don’t just assume your data is better than the existing data, especially if yours is derived from another source and the existing data is from a ground survey. [1]: http://wiki.openstreetmap.org/wiki/Talk:Ordnance_Survey_Opendata#Modifying_Existing_Data Simon -- A complex system that works is invariably found to have evolved from a simple system that works.—John Gall ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] ito and OS Locator comparison
On 13/07/2010 17:30, David Groom wrote: 1) add the slippymap plugin 2) then in preferences advanced preferences , add the following two entries key = slippymap.custom_tile_source_1.name ;value = ITO World OS comparison key = slippymap.custom_tile_source_1.url; value = http://tiles.itoworld.com/os_locator 3 restart JOSM 4 in preferences Slippy Map choose the tile source as ITO World OS comparison David - Original Message - *From:* Bob Hawkins mailto:bobhawk...@waitrose.com I am at a loss to understand how I view the ito OS Locator comparison layer in JOSM. I should appreciate it if someone would kindly explain how to access it. This question and its answer would be perfect content for OSM's new QA system at http://help.openstreetmap.org/ /advert Jonathan ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] “Correcting” existing data with OS Opendata
On 18/07/2010 13:54, Simon Ward wrote: I just added a comment to the talk page about OS Opendata[1]: It seems that some people have been using OS Opendata to “correct” existing data, moving ways to match OS Opendata, and in some cases removing attributes (such as surface=paved). Please, please, please, pretty please don’t just assume your data is better than the existing data, especially if yours is derived from another source and the existing data is from a ground survey. Hi Simon In principle I understand what your saying agree to some extent; except that I think it's incorrect to assume that on ground surveying is necessarily more accurate. GPS tracks are prone to being sent off course by the surroundings such as heavy tree coverage steep topography. In these cases the maps are probably more accurate. Good local knowledge is essential for accurate mapping which is why I feel unsure about amending others traces if I don't know the area, preferring just to add ways that hadn't previously been mapped. Cheers Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] “Correcting” existing data wi th OS Opendata
On 19/07/2010 11:40, Jerry Clough - OSM wrote: This was me, but I know that Paul Sladen, Simon Halsey, and probably others, were also affected. Has anyone has sent the offending user a message? He/she is a relative newcomer, and has edited in Trowbridge as well as Carlton/Gedling. I've been keeping an eye on his/her Trowbridge edits can't see anything destructive, just a couple of minor errors, but we all make those don't we? Overall I thinks he's adding to map. Cheers Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Tagging roadside verge SSSIs
On 30/06/2010 16:01, Glenn Proctor wrote: Hi Near where I live there's a small stretch (about 100m) of the roadside verge that has signs on it saying that it's a Site of Special Scientific Interest. Are you sure it's referring just to the verge not stretching further away from the road (into fields/woods ?) Cheers Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] “Correcting” existing data wi th OS Opendata
On Mon, Jul 19, 2010 at 10:18:45PM +0100, Dave F. wrote: In principle I understand what your saying agree to some extent; except that I think it's incorrect to assume that on ground surveying is necessarily more accurate. GPS tracks are prone to being sent off course by the surroundings such as heavy tree coverage steep topography. In these cases the maps are probably more accurate. OSM primarily maps what is on the ground, not what other geodata says is there. Other data has been shown to be quite inaccurate compared to OSM, including mastermap data. Using our own collective knowledge just produces better results anyway. I’m well up for using OS OpenData to enhance our data, but the cases I’ve seen involve arbitrary moving of ways to directly match OS data, and loss of metadata. Simon -- A complex system that works is invariably found to have evolved from a simple system that works.—John Gall signature.asc Description: Digital signature ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] “Correcting” existing data with OS Opendata
Dave F. wrote: In principle I understand what your saying agree to some extent; except that I think it's incorrect to assume that on ground surveying is necessarily more accurate. GPS tracks are prone to being sent off course by the surroundings such as heavy tree coverage steep topography. In these cases the maps are probably more accurate. That's certainly true, but there are also (for whatever reason) errors in the OSSV data too. The N carriageway of the A38 to the North of East Midlands Designer Outlet is an example of this (around http://www.openstreetmap.org/?lat=53.10942lon=-1.31278zoom=17layers=B000FTF) - edit in Potlatch and you can see that OSM has the carriageway slightly the North of OSSV, but fetch the GPS traces in and you can see that they all pretty much agree that both the OS and OSM have the road too far south. This isn't an OSSV tracing problem as that road was last edited by me reverting part of the RR8 mass road renaming in 2009. Shuffle the background so that the underlying GPS traces match the OSSV data and it's clear that some of the traced stuff on that portion of the map is out by a 4-8m or so, but that doesn't mean that map isn't a good one. However, the resulting map of East Midlands Designer Outlet (at least partly done I think by the same contributor that we're talking about) is now far more detailed and far more useful to someone actually going shopping than it was before. Full disclosure - some of the stuff N of the A38 and S of the EMDA was added by me (and at least one service road traced off OSSV without aligning the background first!) ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Use of OS OpenData in OSM
Hi Folks, Given all of the talk on the osm-talk mailing list about the possibility of losing data if we move to the new licence, I started to wonder just how widespread OS OpenData use is in OSM. I couldn't find a visualisation, so I made one this evening which is visible at http://www.maps.webhop.net/osm_opendata/. Not all zoom levels are rendered yet - it could easily take most of tomorrow to finish the higher zoom levels. The way I have detected the OS derived data is very crude - basically if 'source' or 'source:name' matches %os%, the element gets highlighted in blue. This means that tags relating to out of copyright OS maps might also be highlighted (I see some 'OS7' tags). Anyway, I thought you might be interested in seeing how widespread the use is - I was very surprised that at low zoom levels, the UK (or rather GB) is covered in blue, but if you zoom in enough you can start to see which towns are 'old mapping' and which contain a lot of tracing from StreetView. I'm not sure what to do with this now - I will work out some statistics for how much of the OSM data includes OS opendata. If anyone can think of a use for it now that I have the database imported, please let me know! Graham. -- Dr. Graham Jones Hartlepool, UK email: grahamjones...@gmail.com ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Use of OS OpenData in OSM
On 19 July 2010 23:37, Graham Jones grahamjones...@googlemail.com wrote: Hi Folks, Given all of the talk on the osm-talk mailing list about the possibility of losing data if we move to the new licence, I started to wonder just how widespread OS OpenData use is in OSM. I couldn't find a visualisation, so I made one this evening which is visible at http://www.maps.webhop.net/osm_opendata/. Not all zoom levels are rendered yet - it could easily take most of tomorrow to finish the higher zoom levels. The way I have detected the OS derived data is very crude - basically if 'source' or 'source:name' matches %os%, the element gets highlighted in blue. This means that tags relating to out of copyright OS maps might also be highlighted (I see some 'OS7' tags). Anyway, I thought you might be interested in seeing how widespread the use is - I was very surprised that at low zoom levels, the UK (or rather GB) is covered in blue, but if you zoom in enough you can start to see which towns are 'old mapping' and which contain a lot of tracing from StreetView. I'm not sure what to do with this now - I will work out some statistics for how much of the OSM data includes OS opendata. If anyone can think of a use for it now that I have the database imported, please let me know! Well the first thing to say is that the approach is a bit flawed. You would need to look also at the history to find out what is new (completely OS OpenData) or what has been completed with data from OS. It is very likely that some might come from old mapping. The second point is that I don't see the relation between knowing how much OS OpenData and the switch to the new licence. Talks of losing data is partially a self fulfilling prophecy. It is impossible right now to gauge how much data IF ANY we would lose since we don't have any means to know who is in support of what until the voluntary licence is put in place. Emilie Laffray ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Tagging roadside verge SSSIs
Dave F wrote: Are you sure it's referring just to the verge not stretching further away from the road (into fields/woods ?) Near here we have verges between pavement and adjacent landuse (often fields) which are overgrown with signs at either end (with arrows) and sometimes in the middle denoting them as nature reserves (the sceptic in me read this as cost saving no mowing area), so I'd think it quite possible that there is a verge that is denoted as SSSI if something of interest has been noted growing there. Ed ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
