This is a python script for converting GeoJSON file in WGS84 (epsg:4326) coordinate system to the Mars coordinate system (GCJ-02), which is used for encryption of GPS data in China.
When you download OpenStreetMap data, which is in WGS84 reference, you may encounter a systematic offset of the road network plotted on street maps of China (left). After transformation, the offset is corrected (right).
- Eviltransform library https://github.com/googollee/eviltransform
- The China GPS shift problem https://en.wikipedia.org/wiki/Restrictions_on_geographic_data_in_China
Can Yang, Ph.D. student at KTH, Royal Institute of Technology in Sweden
Email: cyang(at)kth.se
Homepage: https://people.kth.se/~cyang/