[OSM-newbies] Editing a gps trace

[Craig Wallace]

On 04/01/2010 09:36, Rajkumar S wrote:
> Hi,
>
> I have just started contributing to osm. I have a gps device and
> uploaded a trace at
> http://www.openstreetmap.org/user/Rajkumar%20S/traces/590571
>
> Now I want to edit this data and add to osm. As I understand I need to
> open this trace in  JOSM add nodes and connect them to create ways.
> But adding nodes to a gps trace is tedious esp if the way is not
> straight.
>
> Is there a way to turn gps trace to ways automatically so that I can
> just concentrate on adding information than click on the map adding
> nodes just to create ways??

You can open the GPX file in JOSM, then right click on the GPX layer and 
choose "convert to data layer".
Though note that most GPS traces will have more points than is necessary 
for a way in OSM, it is usually best to simplify it a bit.
The "utilsplugin" gives the option to simplify ways in JOSM.

Also, a single GPS trace can be inaccurate. I think its best to get 
several GPS traces for each way, preferably at least one in each direction.
Then in JOSM, you can take an average of them by drawing a way up the 
middle, and this lets you smooth out any obvious errors. The way doesn't 
have to follow the trace precisely, just have enough points to make it 
look like a reasonable curve.

See this page for details: 
http://wiki.openstreetmap.org/wiki/Editing_Standards_and_Conventions#Accuracy


Craig