1. School of Computer Science and Engineering, Xi’An University of Technology, Xi’An, China
2. Land Surveying & Geo-Informatics Hung Hom, The Hong Kong Polytechnic University, Kowloon, Hong Kong
3. Faculty of Electrical and Computer Engineering, University of Iceland, Reykjavik, Iceland
4. School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, China