Diyou LIU¹, Ning Yang², Tianwei Ren³, Quan Xiong⁴, Lin Zhang⁵, Zhenbo Du⁴, Zhe Liu⁴, Jianxi Huang⁶, Xiaodong Zhang⁴, Wenju Yun³ and Dehai Zhu⁴, (1)China Agricultural University(CAU), Department of Geographic Information Engineering, College of Land Science and Technology, Beijing, China, (2)China Agricultural University, Department of Geographic Information Engineering, Beijing, China, (3)CAU China Agricultural University, Beijing, China, (4)CAU China Agricultural University, College of Land Science and Technology, Beijing, China, (5)CAU China Agricultural University, Department of Geographic Information Engineering, Beijing, China, (6)China Agricultural University, College of Land Science and Technology, Beijing, China