[OSM-talk] [Party] Mapping party advice

Andy Robinson Andy_J_Robinson at blueyonder.co.uk
Thu Mar 8 09:47:59 GMT 2007

Iván Sánchez Ortega wrote:
>Sent: 07 March 2007 10:45 PM
>To: party at openstreetmap.org
>Cc: talk at openstreetmap.org
>Subject: [Party] Mapping party advice
>As you may already know, I'm from Madrid, Spain, a place with zero mapping
>parties so far.
>Matter is, a cultural centre (a kind of digital arts museum) will host a 3-
>OSM workshop over april, and I'm the person behind it.
>I'm being provided with GPS loggers, computers with Ubuntu and JOSM, and a
>bunch of people interested in this. One day devoted to OSM, data editing
>JOSM, and two days devoted to a mapping party. Prints of the Madrid map all
>over the place. Meetings with local cartographers. Lots of cool stuff to
>OSM rolling out in spain.
>Problem is, I have zero experience setting up mapping parties, and I'm a
>afraid of messing things up. So, I'm turning to you for advice. What kind
>things should I be aware of? How to split people to walk through the city?
>How many posters to print?


Well done for your efforts in getting something moving in Spain.

A few pointers from experience.

You can get a good idea of what organization has been done for other mapping
parties by checking the relevant party pages on the wiki. Specifically:
Isle of Wight, Mapchester (Manchester), Rutland, Bath, Reading, Bristol and

Print an OSM map of the city (sketch a schematic type map by hand) and
either divide it into logical sectors or leave it for people to carve up
during the event.

Don't try to dictate where people map, let them go where they want but be
prepared to guide those that want to be directed.

Avoid mapping on foot with a GPS in the city centre, the quality of the
tracklogs will be very poor due to the tall buildings (both the lack of
satellites and the signal bounce/multipath off buildings). Ideally persuade
people to go out into the wider Madrid area.

Mapping by bicycle has been by far the most efficient in the UK, except for
the long distance major routes which are more efficiently done by car. Would
be great to get your feedback after the event of the Spanish differences
that come to light.

Don’t forget some could map railways, metro (where it is above ground of
course), waterways and other non highway routes.

For those that are on foot try and get them to concentrate on something that
cannot be done by other transport modes, especially footpaths of course.

It takes a fair amount of time (allow an hour) to bring people up to
familiarity with the process, including the GPS receivers, if they are new
to OSM. So be prepared to let the experienced people get out and then spend
extra time with the new ones.

It’s a good idea to have at least one person at the base all the time to
deal with people coming back in. When people do come back in its nice to try
and get all their tracklogs onto a common computer so that you can build a
tracklog map showing progress. If you colour each track in JOSM differently
then its easy to see who has done what.

Socialise in the evenings, this is where we tend to hook people in for
longer than just the day of mapping.

Make sure GPS units that are loaned out are recording points at 1 sec
intervals but if the unit has a limit (say 10,000) then be prepared to
extend the time between each point to 2 or 5 seconds if a person plans to be
out mapping all day rather than coming back to the base half way through the
day to take the log off the GPS receiver.

I don't think we have got the publicity for mapping events in the UK quite
right yet. Most mapping parties have tended to attract just a small number
of new mappers. Finding a better way to tap into the large number of
recreational walkers and cyclists who are about in the neighbourhood on any
given weekend has been difficult so far. There seems to be less of a problem
interesting the technical folk (hackers etc) but they are sometimes less
interested in getting out and mapping.

Hope this helps.

Cheers & good luck.


Andy Robinson
Andy_J_Robinson at blueyonder.co.uk

>(Just so Steve doesn't get upset about the signal-to-noise ratio in the
>talk at osm list, please reply to the party at osm list)
>Iván Sánchez Ortega <ivansanchez at escomposlinux.org>
>This was the most unkindest cut of all.
>		-- William Shakespeare, "Julius Caesar"

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