Thread: China City Navigator NT 2010.21 (CH) for Garmin

Originally Posted by lh128

First, further tested with other base map and ruled out the possibility of that.

Then tested with older version of China map (701 NT17) and I'm way off the point as expected. My location on the old map was about 500m NW. But the position is correct with map 760 and 2010.21.
On other hand, my coordinate was quite different during the test. On newer maps, my coordinate was about 500m SE from the actual one, according to Google Earth.

So the conclusion is: From version 760 on, the former offset correction file, namely the 6kiB GMAPPROM.IMG file, is included in the map and will change the coordinate instead of change position showed on the map. Anyone with a problem displaying those maps should consider upgrading their software to support the integrated file.

And Garmin will certainly continue making offset, as long as it stays in business in China. The government believes the coordinate is "national security" issue and requires all map publishers make offset, thought anyone now can just download Google Earth and have the exact coordinate.

Hi lh128,

When I use the older map (Map 650) when I visited China last June, I added a file "006B082300.bin" to the /GARMIN directory (i.e., the same directory as the gmapsupp.img). This "006B082300.bin" file corrected the offset (position and coordinate). Have you heard of such a file? Do you know if it work for Map 760 and 2010.21. You can get this file from dropbox [Only registered and activated users can see links. ] if you need it for testing.

Thanks.