Shengqi Zhou, Nanjing University of Science and Technology, China; Guang Hu, Jingqiao Wang, Qi Chen, China Siwei Surveying and Mapping Technology Co.Ltd., China; Junpeng Du, Xingyu Lu, Zhichuan Wang, Jianchao Yang, Ke Tan, Hong Gu, Weimin Su, Nanjing University of Science and Technology, China