[OSM-talk] Contributing GIS Data to OSM

[Serge Wroclawski]

On Tue, Jan 18, 2011 at 10:42 AM, IT Intern <itintern12 at gmail.com> wrote:
>
> This was originally posted here:
> http://forum.openstreetmap.org/viewtopic.php?id=10817

Hi, and welcome to OSM!

There's a large split in the people who use the forums vs the lists. I'm biased.

The other resources for OSM are the Wiki (wiki.openstreetmap.org) and
help.openstreetmap.org.

help.osm has a lot of question similar to yours, and this question
comes up a lot, so I'm going to apologise if this answer seems terse,
there's just a fairly large amount of information that I need to give
you to answer it.


> I apologize in advance if the answer to my question is blatant from the docs, but as far as I can see there seems to be no way to contribute GIS data to OSM.

It depends what you mean by contribute. I'm going to assume you mean
"Put data you and others have collected into OSM"

> I am working on a project making an interactive map and the foundation which I work for has a lot of data which they have collected (mostly from gazetteers).  We figured since OSM is providing us with their lovely base maps from the API, we want to give back to them by contributing our data.  However, our data is mainly in a PostGIS database.  Is there anyway to import this data to OSM?  I appreciate all and any advice you may offer me

For my own sanity, I'll break the process down into several parts:

License, Tagging, the Import Process in General, and Technology

1. License

First, and foremost, any data that goes into OSM must be compatible
with the OSM license, which is currently in a transition period. If
you've signed up recently, you've accepted the new Contributor Terms.

The issue is that you have to be sure that your organisation is okay
with these terms, that you have the proper authorisation to add the
data into our dataset, etc.

There are lots of resources on the wiki, and lists to help with this,
so I won't go too far into the process.

2. Tagging

You didn't mention what kind of data you have. If you understand OSM,
then you know how we use tags to classify features. Your data will
need to be added in using tags that our system understands, or if it's
an odd case where the data is unlike anything we already have, we'd
need to work out a new tagging system for it. But the later is very
unlikely.

If you have questions about this, lots of people will be happy to help
you, but the best resource is the wiki.

3. Imports in General

As a general rule, OSM doesn't like mass data imports, for lots of
reasons. There are exceptions, people do imports, and some are fine,
but generally the community doesn't like them, and usually it has to
do with poor execution, and overlapping data.

For example, let's say you have road data that you want to add to OSM.

Will your import process take in to account roads that are already in
the database? If so, what strategy will you use for deciding which
data is correct? Will you look at the date of collection? Will you
always blow the existing OSM data away, will you always blow your data
away?

And if you do add roads, will they route properly with existing OSM
data (ie will they be topologically consistent with the existing
dataset?). And so on...

It's a non-trivial matter, and the process needs to be customised for
each dataset.

We can go into more depth about this, but look at the wiki for
"import" and "imports" and you'll see lots of existing information.

4. Technology

If your data is in PostGIS now, it shouldn't be too hard to write a
script that extracts the features and makes it available in the OSM
XML format, ready to be consumed by the API.

Are you familiar with the XML format and the API? If not, they're
referenced in the wiki and or we can give you a link.

- Serge