[Openstreetmap] Inner city accuracy

[Robert Scott]

The way I do it is to travel a troublesome street several times, until I can 
draw an average which is consistent with all the intersections.

If you're really determined, you can also check a GPS sat calculator such as 
the one at http://mappinghacks.com/projects/gpscal/query.shtml to see at 
which times you'll be likely to get a good fix.

I've also considered the use of an inertial system - to do the insides of 
tunnels. But my friends told me I was being pedantic.

-robert


On Wednesday 25 Jan 2006 21:22, Lars Aronsson wrote:
> 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?