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Comment by bkor | Hacker News Reader

The title implies a bit more than what the article says. Basically China doesn't like their country to be mapped. As a result supposedly it's pretty difficult to use most navigation software (e.g. Google Maps) within China.

China is NOT blocking it because it is self-driving (which is what you might assume). China blocks pretty much any mapping.

I haven't been to China btw; I'm curious if OpenStreetMap would work.

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China is on OSM. There is only a measley 383MB of map data though, about the same level of detail as Sweden.

http://download.geofabrik.de/asia/china.html

Agree. Misleading title. It is not specific to China, by the way. South Korea doesn't like that either. Think of it as a privilege, not a right, just like driving.

https://www.voanews.com/a/google-maps-data-south-korea/36021...

I don't think its that simple and I'm curious what's really up.

I was just in Shanghai, Nanjing, Hangzhou for a week. I purchased a Hong Kong sim for my phone. Google and Facebook were not blocked when using tbat sim but they were blocked on hotel WiFi.

So then trying Google Maps the location was always wrong. So wrong as to be unusable. But, trying Apple Maps it was always correct. It seems like that could only happen by regulation not technical means. The iPhone itself isn't going to give different GPS info depending on which app is running is it ? Which seems to means Google Maps' location is wrong because the Chinese government told Google to make it wrong?

Google Maps are intentionally offset in China to comply with regulations because the global version doesn't have a license to operate in China: https://en.wikipedia.org/wiki/Google_Maps#Google_Maps_in_Chi...

Apple Maps in China uses Autonavi maps which are licensed by the Chinese government. Note that these maps are different than the maps seen in Apple Maps outside of Mainland China.

Google and Facebook weren't blocked using your Hong Kong sim because roaming sims tunnel data out of the country and connect to the internet there (like a vpn!).

In the past, ditu.google.cn (only accessible within mainland China, I believe) un-offset the data. I don't know if that is still available.

Correction: They block pretty much any mapping not done by Chinese companies. I could navigate around hutongs (old windy neighborhoods which aren't always easily mapped) with QQ Maps without a problem.

I’ve used Maps.me (which uses OSM) with great success in China.

https://en.wikipedia.org/wiki/Restrictions_on_geographic_dat...

As I have occasionally worked with geodetic coordinate conversions in the past, that GCJ-02 datum sounds like an incredibly bad idea.

The worst accidental mistake I have ever made with respect to geodetic coordinates, relating to accumulating floating-point round-off errors, absolutely pales in comparison to the sheer idiocy of introducing errors into your geodetic datum on purpose.

Look, people, satellite photography exists now. That objective reality maps really well onto a coordinate systems based on a smooth ellipsoid. If you intentionally make your domestically-produced map products harder to use for people in your own country, they will buy better maps from other countries. If your goal is to make your 50 most important military assets harder to find, and in the process make it harder to find a billion civilian assets, you're going to lose more money just paying all those delivery drivers to get lost for 20 minutes than it would cost to rebuild those 50 military assets 10 times over.

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