Don't forget Sources...

I am hoping that we wouldn’t forget to put sources in our editing. This is mainly as a note to others where those tracks/ways come from.

What I fear is that some might get data from google/mapping software (copyrighted including malfree/malsing) and then incorporate them into OSM. Which, possibly, would then lead to deletions, and I don’t think that is a good thing. What if someone skipped mapping the area after thinking that streets etc in that area has been mapped (without knowing that it will be deleted eventually due to copyright violations) ? Want to do things twice with our small party of active mappers?

In addition, citing sources would ease the suspicion of others, like noticing how somebody in germany added primary roads in malaysia where bing imagery doesn’t exist. Something like that… I mean if it is from well meaning tourists, wouldn’t it be wonderful to know that they contributed to our osm map? Just a source=gps would answer that.

Well, geng, consider this as an improvement to our mapping standards.

Happy mapping!

To try to use and understand this meta-data will always be a bit hit and miss. Different mappers have different ideas for how to use the source tag. e.g. Adding the tag on elements versus changesets is a fundamental difference. All sorts of other open questions too though. There’s more information on what’s agreed (and what isn’t) on the wiki page Key:Source.

I think the source tag is worthwhile, because even if it’s only partially or inconsistently used, it can be helpful information for other mappers. but there are limits.

I also think it’s not very important. We have to face the fact that some mappers don’t bother with it. I don’t think it’s something we should agonise over too much. Also it’s fine, when you’re teaching a new mapper, to skip over this in the first few lessons. It adds some complexity to a mapping process which may otherwise be extremely simple. For example if you’re just teaching somebody how to add their local restaurant as a first ever edit… don’t start telling them to add a source tag.


I understand your concern. I was mainly emphasizing on sources for road and highways since there are quite a few, more detailed non-open road maps available for Malaysia compared to OSM now (traces to make from Bing is limited to few key areas). The allure to just import from copyrighted sources and incorporate it into OSM must have been great.

In summary, although OSM road map coverage for Malaysia is still far from satisfactory, a slow and steady mapping effort is better than trying to copy from non-open sources.

May I suggest you guys have a look at Kuantan area to realize why it is important to include sources in your edits. A lot of roads are not aligned to the imagery (which I suspect from previous mapping using gps), while some are traced from the bing imagery. Which brings in a dilemma, should we realign/shift the imagery to the older mapped roads (none was tagged as from gps source), or should we realign everything to the imagery?

From my experience, gps tracks from my samsung is pretty consistently 10-15+ meters away from imagery for certain parts of KL and Kerteh (I placed the samsung on dashboard to get the best satellite coverage. Despite using gps of a smartphone, it will show me going both ways of a 2 lane road). With gps tracks, at least we have some reference to align the new imagery, although with some loss of accuracy, rather than just accepting the imagery as it is.

What should I put if I am familiar with that area because I stayed there? Should I put sources=survey?

Welcome to OSM,

Here’s a list for sources on wiki:

Sources=survey can be used and encouraged. Not all bing imagery is up to date, sometimes a major roadwork has been completed that is not reflected by bing.

Again, welcome to the few, the proud, the osmmappers… :stuck_out_tongue:

Let me bring this thread up again.

I see that we have a few more local mapper contributing to OSM - malaysia map. We appreciate your contributions. But…
please include sources to your highway (etc) trace. Basically, any areas that doesn’t have a high-res Bing images (auto-filled source tag if you map using Potlatch, hit b) will benefit greatly from source = xxxx tag. Especially if you are importing data from other permissible sources.

Remember how that licensing cleanup which left areas needing to be re-traced? The same thing can happen if other map providers start a dispute with OSM due to your use of copyrighted sources. By the way, please check with malfreemaps regarding their map use policy before importing them into OSM, and possibly share with us your findings.

Happy mapping. :sunglasses:

Also note that the source can be given when uploading your data, e.g. in the comment of the changeset, or even as a source tag for the changeset (with JOSM - don’t know for Potlach etc.). That does not “spam” the actual data.
By the way, uploading your GPS traces is even more important: it is a valuable information for others to see the “correctness” or offset of aerial imagery, and of course someone who travelled along a road can be expected to have better information than a coach mapper.

Should I comment that it’s from my traces or do I have to copy and paste a link?
What should I write when it’s places I’ve frequently used or familiar with?

Two cent take:

source=GPS tracks

This is what I usually put for things that I derived from my own GPS tracks. You may further include anything else in the changeset comment. That is the best way to make things easier.

For such places that you have mentioned, use

source=Local knowledge

Key:source on OSM wiki

Hope this helps!

Thanks, I’ll need to go back to correct my sources. :slight_smile:

Just another case in point:

It makes you wonder how they traced this portion of the highway. Bing coverage doesn’t exist for this area, while Mapbox has just recently been available. If it is traced using gps, then something is really broken because the trace is about 100m++ off from Mapbox images. Even with SA during the Clinton times won’t give this kind of offset. :smiley: