Quote Originally Posted by felix View Post
Hi td-ref, no problem i'm happy to share. I'm not sure what you mean by that question. I used googlemaps to calculate the offset, and it's actually quite easy:

(This only works in maps.google.com, it doesn't work with ditu.google.cn)

In googlemaps right-click on an intersection of two roads and select "what's here". That gives you the coordinates of that point, for example 31.375452, 120.951090
Then switch to satellite view, find where that intersection really is, and using right-click again get the coordinates for that, in this example it will be 31.377550, 120.946839
Then just subtract one from the other to find the offset. So in this example the offset is +2098, -4251

I get slightly different values every time i do it, but it doesn't make any big difference on the phone. Also remember that the offset is different in other parts of China, so if you're in Shenzhen you should find out what the offset is down there!
I did some investigation on the GM offset as well.

- The difference from now to next time may be related to the zoom factor.
- I heard the offsets are random (within certain limits) but Google folks seem to have a muzzle

I came across this website. hey have a database which might be useful - haven't checked it out though.