Published on in Vol 22, No 11 (2020): November
1 School of Computer and Information Engineering, Zhejiang Gongshang University, Hangzhou, China
2 Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing, China
3 State Key Laboratory of Resources and Environmental Information System, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
*these authors contributed equally