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 +0000, 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
