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 Hulunbeiermen g Leymus chinensis grassland, Inner Mongolia, China was made using Landsat Thematic Mapper data. Starting with the ecological principles of plant popu lation, and based on observed data in fixed positions of the experimental r egion, a synchronous revision of the practical measurement of grass yield w as made by using a logistic equation for the case that the measurement time and the satellite pass time are not synchronous. Statistical analysis resu lts show that the interrelation between the revised grass yield and Ratio V egetation Index (RVI) has been considerably enhanced. The correlation coeff icient, r = 0.856-0944, shows a remarkable positive correlation, while the correlation coefficient of the unrevised grass yield is only 0.679-0.817, w hich does not pass the notability test of the alpha (0.01) level. The forec asting result of the grass yield of the Leymus chinensis grassland, in Ewen k Banner of Hulunbeiermeng, Inner Mongolia, China, also shows that the fore cast value agrees well with the measured value.