1. Department of Geography and Environmental Studies, Texas State University, San Marcos, TX 78666, USA
2. Geoinformation and Big Data Research Laboratory, Department of Geography, University of South Carolina, Columbia, SC 29208, USA
3. Oden Institute, The University of Texas at Austin, Austin, TX 78712, USA
4. Geoinformation and Big Data Research Laboratory, Department of Geography, The Pennsylvania State University, University Park, PA 16802, USA
5. College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 265800, China