[Openstreetmap] Inner city accuracy

[Lars Aronsson]

After several months of mapping motorways, country roads, and 
suburban sprawl (with gardens and low buildings), I'm returning to 
the inner city streets of my own town.  There are lots of tracks 
here, lots of yellow dots in the OSM editing applet.  Sometimes 
the streets appear to be broader than the house blocks that 
separate them.  How do you reach any acceptable level of accuracy 
in mapping cities?  Should one go out at night and stand at the 
middle of an intersection, doing a GPS average over ten minutes? 
Are some GPS units better than others?

Are there any affordable consumer level inertial navigation 
systems?  http://en.wikipedia.org/wiki/Inertial_guidance_system

Or should we wait for WAAS or Galileo to give us better accuracy, 
before we can do useful maps of inner cities?


-- 
  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se