Funding for this research was provided by:
National Key Research and Development Program of China (2020YFB0505800, 2020YFB0505804)
National Natural Science Foundation of China (41931076, 41874032, 41731069)
State Key Laboratory of Geo-Information Engineering (SKLGIE2019-Z-2-2)
Article History
Received: 30 April 2021
Accepted: 13 August 2021
First Online: 25 August 2021