Ask HN: How are mapping organisations notified of land border changes?

21 points by OJFord ↗ HN
In the news today is a land-exchange between Holland and Belgium [0].

How are - if indeed they are - the Ordnance Survey, Google Maps, and other entities notified of the precise changes, coordinates that allow them to recreate the division in their maps?

[0] - http://www.nytimes.com/2016/11/28/world/europe/belgium-netherlands-land-dispute.html

3 comments

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Great question.

Most countries have a mapping agency/authority (https://en.wikipedia.org/wiki/National_mapping_agency). I've always assumed that each country defines it's own spatial boundary defined by the relevant legal agreements that define a country. Third parties such as Google presumably use whatever each country provides and try to stay out of any disputes (http://qz.com/218675/here-are-the-32-countries-google-maps-w...).

As far as updates, someone probably just has an annual calendar reminder to pull the latest shapefile for each territory or from a central authority (UN? National Geospatial Agency?)! The geographer in me is mildly amused at the thought of someone in Belgium making a pull request to The Netherlands related to updating a boundary.

If you're interested in questions like this, I highly recommend the FOSS4G conferences (http://2017.foss4g.org/). Many of the big names in GIS attend and can likely give an authoritative answer on questions such as this.

Many countries get their information from their own national imagery and mapping agency. For the United States it is the National Geospatial-Intelligence Agency or NGA. For countries that need help with this information or need higher quality imagery they normally can get assistance from the NGA through their government and commercial partnership arrangements.