1. Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
2. Institute of Cartography and Geoinformation, ETH Zurich, Zurich, Switzerland
3. School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, PR China
4. Department of Computing, The Hong Kong Polytechnic University, Kowloon, Hong Kong
5. State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing, PR China
6. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, PR China