Even Google Maps does this for the Chinese version of their map. Some mapping systems will shift the satellite images to match the map. Well, that may be true for Google Maps for now, but that could change. Now, you might be thinking that even though the map is shifted you can still at least count on GPS coordinates to appear correctly in the satellite images. Now let’s say you had the GPS coordinates for Tiananmen Square ( 39.902722,116.391441), located near the center of China’s capital city Beijing, and wanted to plot it on Google Maps.Īccording to the map, these coordinates would currently put you at the Beijing City Administration Institute (left image) however, if you were to look at the satellite image layer (right image) you would see that the coordinates do point to Tiananmen Square. Google Maps currently displays the satellite image tiles using the same GPS standard as the rest of the world, but the map data for China is in a different standard, hence the two do not match.
On the right we have the satellite image with the map overlaid on top and we can clearly see the GPS shift with the map of the roads spilling into the river. On the left we have just the map of the area. Pictured above are images from Google Maps of a portion of the Huangpu River in Shanghai China. Since maps of China use a different standard than the one used by GPS it causes the GPS coordinates to appear off, sometimes by a large amount, and this is known as the China GPS shift problem. The short answer is that China does not use the same GPS standard as the rest of the world to plot coordinates on a map. The satellite images simply do not match the map, but why is that?
Have you ever tried using Google Maps, Bing or other mapping services to bring up a map of China? If so then you may have noticed that satellite images do not match up with any of the geographic features on the map, such as roads, rivers, points of interest and just about everything else.
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