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Pretty straightforward question here.

At an increasing rate I see crowd sourcing data being mapped to great effect. Where are the raw data sources for all these maps? I know they vary but I don't think I have even found a single source.

For instance, twitter maps, where is the data?

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Could you post a link to one of the maps you're seeing? – Simbamangu Dec 28 '11 at 16:37… – Thad Dec 28 '11 at 17:44
up vote 8 down vote accepted

Some places like Twitter connect geographical data with the content ("tweets" in this case). If you use the API to request a list of recent tweets, it will give you geographical data along with it ("coordinates", "geo" in the JSON response):

Twitter API Example

I suspect most of the data you're referring to is collected similarly. Basically,

  1. find a potential source of data with geographic information attached to it,
  2. find out how to query their API, and
  3. compile the data into a format your GIS tools can understand.
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That's what I needed to know! Thanks Donald. – Thad Dec 28 '11 at 19:32
If you're interested in Twitter, this is how I did it: – underdark Dec 28 '11 at 20:47

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