The next London evening mapping session & pub is on Wednesday.

Last time we were over in Fleet Street. As it was almost two weeks ago now we've all input our data, and the result looks great. Much less of an ugly gap in building coverage there. That particular patch was actually the centre of the cake for our massive mapping party back in January 2007, based at the MultiMap offices. Since then it was considered to be one the best mapped parts of London for a long time, until we started on the building outlines and super-POI details. Then it became an ugly gap because the buildings are hideously complicated in this area. Old buildings meeting new buildings at funny angles, with narrow allyways and pedestrian tunnels everywhere. Very difficult to see clearly in yahoo, and the building outlines are not particularly easy to map on-the-ground either. This is particularly true of my slice just to West of the pub.

I thought if we can map the buildings outlines there, we can do it anywhere, but working with all those funny angles did take me way too long. I shall have to go back and finish my slice some time.

I think some people gave the area a bit of a POI boost too before heading for another great session at Ye olde Cheshire Cheese pub.

Matt began with the sentence

"Here's an interesting question about ODbL"

...which made everyone laugh (can't remember what the question actually was, but I'm sure it was interesting really)

We talked about the latest tile usage and abusage. Andy suggested we direct everyone to premium.gravitystorm.co.uk (doesn't exist yet. But it should do)

We talked about some server problems which had occurred due to pgstats going haywire resulting in slow innexorable increase in i/o load.

We talked about landuse mapping, and some of the questions it throws up. In particular, should a patch of landuse up against the edge of a road be mapped with a polygon with overlapping segments (nodes shared) with the road? That old chestnut. Here's an easier question: Should an admin boundary which follows along a road be represented as duplicate nodes? There wasn't much debate in the pub. Clearly the answer is no, but you'll find people who want to debate this anyway. *Sigh*

We talked about the new Surrey Air Survey which is some of the finest aerial imagery we've had our hands on. Very high resolution. Some people have been busily positioning the centreline of the road perfectly against this imagery, but we discussed accuracy of the rectification, and how they must have to compensate for hills.

User:Amm was updating us on his progress with a branch of the rails port with OpenStreetBugs integrated (code)

And we talked about "splattering on passports". That's what it says in the meeting minutes. What was that conversation about?

So next meet-up is Wednesday. Cake diagram is now available. You'll notice a focus on missing building patches again. Sign up for slice if you fancy it or feel free to map something different. Bus routes etc. I thought we'd do one more very central one, and maybe start to look slightly further afield for future summer mapping parties. we're also shaping up for a good government-related hack weekend. How can OpenStreetMap help UK local councils?. Add your ideas.