Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I need a map I can display that lets the user click on a point then returns the Lat and Lng.

EDIT TO CLARIFY @Igor: Yes, the user is clicking a specific feature on the map so I guess it would constitute "tracing over imagery".

EDIT: The returned lat/lng can be fairly inaccurate, say even 10m or 20m away.

The issue is that I need the Lat/Lng data to be freely usable with no legal restriction.

For instance, from

If I have data derived from OSM data, do I have to distribute it?

The licence does not force you to distribute or make any data available. But if you do choose to distribute it, or anything derived from it, it must be under the same licence terms as the OSM data.

The area to be mapped is Edinburgh, UK. Ordnance Survey is definitely not an option.

Is this going to be possible?

(We are actually going to be doing an open data service, so we may be able to use Open Street Map data, but I would like to see if there is a freely open option first.)

Thanks, James

share|improve this question
For Edinburgh you can you Ordnance Survey Opendata - Codepoint is the postcode data and Meridian2/OS Vector District is the road/topographic features - free to use and some of this data is already in - osm wiki on it – Mapperz May 17 '12 at 13:21
@Mapperz Thank you, that is very handy and we are looking into that. – James May 22 '12 at 9:04

I think it is possible to derive information from yahoo maps, which has no licensing issues. Infact, OSM data itself is derived in some places by drawing on top of Yahoo maps.

See these page:


share|improve this answer
Wiki says "Note that as of late 2011, Yahoo are shutting down their mapping unit and this imagery service will be switched off without notice." altho Yahoo maps is still there. Do you know if this is still valid advice? – James May 17 '12 at 13:22
Yes, you are correct, they have shut down their API as of Sep 2011 – Devdatta Tengshe May 17 '12 at 13:32

The lat and long are not actually derived from the data, so I don't think that there would be any licensing issues in your case. The lat and long are produced by whichever software package you are using to generate the maps.

For example, if you make a PDF and enable the geospatial location tool, the coordinates it reads would be the same whether you have data within the map or not.

share|improve this answer
The user clicks somewhere on the map because the map shows something is there. So this basically constitutes tracing over imagery, which is problematic from the licensing perspective. But I guess it depends on WHAT the user is supposed to indicate by clicking on the map. – Igor Brejc May 17 '12 at 4:37
@igor The user is clicking a specific feature. Edited question to be clear. – James May 17 '12 at 8:26

I notice OSM is allowed to trace over Bing Arial Photography, so will be looking into that to see if other parties can do the same with no derivative-licensing issues. Anyone know more on this?

share|improve this answer tells that they only allow tracing from satellite images, not other types of maps. And that's for OSM community, I'm not sure the permission was granted for other uses. Even if it is, this means you will have to show pure satellite imagery without any overlay renderings (i.e. no street names etc.) – Igor Brejc May 22 '12 at 12:01
Yup, the imagery only bit is fine. It's the permission to OSM or all issue that I'm wary off. – James May 22 '12 at 23:28

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.