Quote Originally Posted by jpooh View Post
How is the shift done and can it be done for any map? I would like to try it on some maps that i know to be way off. My road tracks lay on top of each other, but they are not on top of the road lines on the gps display.
For China maps, the shift is added when the maps are compiled. It cannot be done on any map as you need the source files of that map to compile.

If your tracks were recorded in China with WGS84 coordinates, then you can show them correctly with the Venus shift-corrected China maps, available in this forum.