I've spent close to two full days trying to understand the nature of the infamous GPS shift in China. After sifting through the noise, two recurring symptoms are that:
The two questions suggested as possible duplicates don't answer exactly what the cause is; rather, they describe symptoms.
أكثر...
- GPS coordinates (WGS-84) plot poorly on Chinese maps, with an offset ranging from 50 to 1000 meters.
- Google and Apple Maps in China have severe misalignment between their street maps and satellite imagery (live example)
- Cold War-era regulations mandated introducing random offsets into GPS chips due to security concerns
- protectionist measures aimed to favor GPS devices manufactured in China
- China simply uses a different projection system, and the offsets are not random
- GPS chips manufactured in China offset the coordinates they return, in order to match approved Chinese maps, which must follow the GCJ-02 datum
The two questions suggested as possible duplicates don't answer exactly what the cause is; rather, they describe symptoms.
أكثر...