The Methods Of Verification And Assessment On The Estimation Of Crop Yield Based On Remote Sensing

The estimation of crop yield is one of the key techniques of yield estimation based on remote sensing, its feasibility and precision will influence the counterpart of the total yield estimation directly as well as the trust of the decision surport departments, therefore, we must make an verification and assessment on it. The purpose of this dissertation is to verify and assess the feasibility and precision of crop yield of China Crop Watch System Using Remote Sensing by the approaches that will combine mul-source data with mul-angle, and integrate quantification with qualification. The main studies are as followings:(1) Divide the common methods of verifying the precision into four sorts: Regard the statistical data of department as the standard; Look on the special sample data as the standard; compared with the actual data obtained from the corresponding area; the comparison between different means and models, this paper adopts the fourth sort.(2) Analyse the the feasibility and principle of the estimation subsystem of crop yield and the counterpart of the food yield subsystem of China Crop Watch System Using Remote Sensing. Bue to the different principles of the two subsystems, the results estimated by the two subsystems will be able to compare each other and should draw the same conclusion so as to verify and assess the estimation of crop yield. Taking the year 2003 as an example, the paper compares the yield change of the crop yield subsystem with that of the food yield subsystem.(3) Respectively compare statistical yield and the sensitive parameters of the vegetation index NDVI with the estimation yield, and qualitatively analyse the tendency change of the time sequence of the three. And then combines meteorological yield, simulates the real yield of the statistical yield, estimation yield and meteorological yield, and finally use the model GM(1,1) which has been set up by grey sysytem theory to quantitatively assess the precision of the estimation.What have the above analysed shows that the principle and method of the estimation of crop yield is feasible, and can assure the required precision, and that simultaneously indicates that compared with the common methods, the ones mentioned in the paper are more comprehensive, reasonable and feasible.