[OSM-dev] Feature request for OSMApplet for London Mapping event

Dave osm at randomjunk.co.uk
Tue Jan 9 18:02:13 GMT 2007

Robert (Jamie) Munro wrote:
> The upcoming London mapping party may be interesting as it will be the
> first time we can use aerial photographs to pre-populate a map with
> segments before the event takes place, then at the event just join the
> segments into ways and tag them.
> I've had a quick look at the area to be mapped in the applet, and it
> looks like the roads we already have of the area don't have anything
> like enough nodes to use for all the junctions along them.
> Can adding a feature to OSMApplet to allow insertion of extra nodes into
> ways, like in JOSM be put high on the list of priorities?
> If this feature was added, it would probably enable a lot more to get
> done at the London event.
I've been adding some streets from the City using the applet, and I can 
tell you now that this would be the most time saving useful ability 
available... the other is the ability to delete segments, which doesn't 
seem to work all the time. What I've been doing is editing with the 
applet, with JOSM in the background to insert nodes on ways in roughly 
the right place then nudge them into place with the applet.

One piece of experience from doing this is how difficult pre-segmenting 
actually is -- the aerial images just aren't good enough to accurately 
determine when there's a road or just two buildings with a gap, or 
different heights so a shadow. This part of London is just packed with 
named cut-throughs which barely show up, and conversely blocked or gated 
loading roads which aren't named and only a building owner can use.

What would make things a lot easier is a print out of the satellite 
photo on which to annotate things as you pass by. This makes 
pre-segmenting unnecessary, and makes copying your notes into the applet 
(potlatch when available) a lot easier. Yahoo! let you print the 
satellite photos for personal use... I don't know what this does to the 
OSM tracing agreement though. I'd have thought it was OK. Any thoughts 
from those who know about that?

> Adding a live GPS read facility to JOSM would be ideal, as suggested here:
> http://lists.openstreetmap.org/pipermail/dev/2006-December/002589.html
Normally when I map I do the whole GPS and digital camera thing -- this 
is useless in central london and the city as the GPS barely gets a lock 
on the big wide roads, never mind the rest, and when it does lock, it's 
about 100m accurate. An in car GPS system with bigger aerial might stand 
a better chance I suppose.


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