A method of modifying error for non-synchronicity of grass yield remote sensing estimation and measurement

A remote sensing yield estimation of aboveground phytomass in Hulunbeiermeng Leymus chinensis grassland, Inner Mongolia, China was made using Landsat Thematic Mapper data. Starting with the ecological principles of plant population, and based on observed data in fixed positions of the experimental region, a synchronous revision of the practical measurement of grass yield was made by using a logistic equation for the case that the measurement time and the satellite pass time are not synchronous. Statistical analysis results show that the interrelation between the revised grass yield and Ratio Vegetation Index (RVI) has been considerably enhanced. The correlation coefficient, r =0.856-0.944, shows a remarkable positive correlation, while the correlation coefficient of the unrevised grass yield is only 0.679-0.817, which does not pass the notability test of the f 0.01 level. The forecasting result of the grass yield of the Leymus chinensis grassland, in Ewenk Banner of Hulunbeiermeng, Inner Mongolia, China, also shows that the forecast value agrees well with the measured value.