1 引言 虽然事实已经证明用卫星资料估计农业产量比较困难,但是,利用NDVI还是取得了一些成果。这些成果大都把重点放在研究产量与NDVI单点观测的关系上。但是最有前途的方法之一还是使用NDVI时间累积预测产量。这里预测籽粒产量或总生物量的简单模型都是由线性回归技术确定的。模式之间的主要差别在于NDVI时间累积的定义不同;有的把时间累积定 1 Introduction Although it has been proved difficult to estimate the agricultural output using satellite data, some achievements have been made in using NDVI. Most of these achievements focus on the relationship between yield and single point observation of NDVI. But one of the most promising ways is to use NDVI time to predict cumulative production. The simple models for predicting grain yield or total biomass here are all determined by the linear regression technique. The main difference between the modes is that NDVI accumulates different definitions; some accumulates time