In-Season Estimation of Rice Nitrogen Status With an Active Crop Canopy Sensor. - Yinkun Yao; Yuxin Miao; Qiang Cao 002; Hongye Wang; Martin L. Gnyp; Georg Bareth; Rajiv Khosla; Wen Yang; Fengyan Liu; Cheng Liu (IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens., 2014)