1. Chinese Antarctic Center of Surveying and Mapping, Wuhan University, Wuhan 430079, P. R. China
2. Key Laboratory of Polar Surveying and Mapping, National Administration of Surveying Mapping and Geoinformation, Wuhan University, Wuhan 430079, P. R. China
3. Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, The Netherlands
4. School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, P. R. China
5. Tianjin Hydrographic Center, The Navigation Guarantee Center of North China Sea, Tianjin 300222, P. R. China