¹J. Lu, ¹Z. Chen, ²Y. Miao, ³Y. Li, ⁴Y. Zhang, ⁴X. Zhao, ¹M. Jia

1. College of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China.
2. Precision Agriculture Center, University of Minnesota, St. Paul, MN 55108, USA.
3. National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
4. College of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China