Study On Monitoring Of Remote Sensing Of Cotton In North Of XinJiang With Hyperspectral Data

This paper utilizes the multitemporal phase hyperspectral data of 8 cultivars of cotton in North of Xinjiang (two of them set up four different plant densities), based on multivariate statistical analysis of high hyperspectral data by using stepwise regression analysis, The regression mathematics equation has been built by using the first derivative spectrum value at 748nm wavelength(the wavelength of maximum correlation coefficient) and canopy leaf chlorophyll density or leaf nitrogen accumulate; through the estimating of testing samples,it shows that the standard error is 0.302g/m~2,and the estimated accuracy is 86.3%,this model has the better application potential.It shows that there is a unanimous variation tendency between chlorophyll density and leaf nitrogen accumulation of cotton canopy with growth stage,( present extremely remarkable positive correlation r=0.9281 **).Reflectance spectrum and the first derivative spectrum respond to chlorophyll content of cotton, extracting the information of chlorophyll density of cotton canopy , it can indirectly monitor the nutrition state of the cotton leaf nitrogen accumulation .The four parameters of cotton leaf nutrition :leaf chlorophyll content, canopy leaf chlorophyll density, leaf nitrogen content ,canopy nitrogen accumulation, correlating analysis with the output respectively, confirmed the best relationship period among them, it has offered the theoretical foundation for the cotton output estimated by using remote sensing.Based on Red edge ,Blue edge, Yellow edge of the first derivative spectrum of canopy cotton show , the six parameters coefficient of variation of Dr, SDr, Db, SDb, Dy, SDy are increasing with the growth stage. It shows that red characteristic of three kind of cotton leaves i.e. normal type , slight early ageing and early ageing type , cotton leaf of early ageing red position shift 18nm to blue wavelength, it prove that the red position change can monitor the nutrition state of the cotton, offering the information for predicting the fact that the cotton defends the early ageing .