The Canopy Spectral Features and Remote Sensing of Wheat Lodging

The ratio and illumination of wheat plant’s leaf and stalk in spectrometer’s field of view change due to wheat lodging,so it is possible to detect the lodging grade by remote sensing technique.Firstly,the spectral difference between leaf and stalk is analyzed,and how canopy spectral reflectance increases with lodge angle is explained.Secondly,because the relative increase of spectral reflectance in visible bands is larger than in near infrared bands,the significant negative correlation model between lodging angle and NDVI was built by statistical analysis.Finally,two LandSat ETM satellite images of April7(before lodging)andMay9,2003(after lodging)were selected,and the ratio of NDVI derived fromthe two images was statistically correlated to the lodging grade,and the lodging grade was successfully regressed.