# Wikidata:Coordinates tracking

This page describes what **coordinates tracking** is and how it should work. At the moment every Wikipedia has location information stored locally. Wikidata items also contain location information for a lot of items using coordinate location (P625). This data should be compared to add missing coordinates to Wikidata, to fix errors and to improve quality of coordinates here.

Several possibilities

- Coordinate on Wikipedia, but not in Wikidata (Category:Coordinates not on Wikidata (Q15181099)) -> import it
- Coordinate on Wikipedia and on Wikidata (Category:Coordinates on Wikidata (Q15181105)). Two options:
- Coordinate on Wikipedia and on Wikidata and both are exactly the same -> do nothing
- Coordinate on Wikipedia and on Wikidata, but these coordinates are not the same. This is where it gets interesting.

Comparing two coordinates is going to be a challenge. Obvious errors (wrong part of our earth) are easy to spot, but two coordinates a meter apart shouldn't be showing up as an error. We should make a coordinate compare function in lua that takes into account the precision (/zoom) and has thresholds to not get (too many) false positives. Once we have that we can start improving our coordinate data.