"Here’s where it gets interesting — GCJ-02 is based on WGS-84, but with a deliberate obfuscation algorithm applied to it. The effect of this is that there are random offsets added to both latitude and longitude, ranging from as little as 50m to as much as 500m
(...)
it’s against the law in China to convert GCJ-02 (obfuscated coordinates) into WGS-84"
@Saint_loup@MoritzBrouhaha This is very interesting. Wonder what the situation with #OpenStreetMaps is? Seems like it would depend – some coordinates that are accurate, because they are based on satellite images, but others that are offset, if the person placing an amenity happens to have obfuscated position information.
@Saint_loup@MoritzBrouhaha According to Wikipedia OSM is mostly accurate?
”Satellite imagery and user-contributed street map data sets, such as those from OpenStreetMap also display correctly because they have been collected using GPS devices (albeit technically illegally – see Legislation).”
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