准确、快捷、实时地对苹果树冠层土壤和作物分析仪器开发(SPAD)值进行高光谱估测，对苹果树的长势监测具有重要意义。连续2 年测量了62 个果园的196 棵苹果树冠层光谱反射率及SPAD 值，分析了原始光谱及连续统去除法处理后的光谱与SPAD 的相关性，并对连续统去除法处理后的光谱在350~1300 nm 范围内，计算了任意两波段组合而成的归一化植被指数(NDVI)、比值植被指数(RVI)和差值植被指数(DVI)等光谱指数。利用逐步回归和主成分分析法，提取主成分作为自变量，构建了估测SPAD 的支持向量机回归模型，并用第2 年采集的数据进行了验证。新建的3 类植被指数中，与SPAD 相关性最大的植被指数分别为NDVI(406，563)、RVI(406，565)和DVI(646，695)，相关系数(r)分别达到了0.677、0.690 和0.711。对支持向量机回归模型进行验证，预测集决定系数(PR2)达到了0.837，预测集相对误差(REP)为1.190%，预测集相对分析误差(RPDP)达到了2.213。连续统去除法及光谱指数均能提高光谱与果树冠层SPAD 的相关性，并且与SPAD 相关性较高的光谱指数是由可见光波段组合而成，支持向量机回归模型对新梢旺长期苹果树冠层SPAD 具有较好的估测能力。

Accurate, rapid and non- destructive estimation of apple canopy SPAD (soil and plant analyzer development) values using hyperspectral remote sensing has important significance for monitoring the growth of apple trees. Spectral reflectance and SPAD values of 196 apple canopies are measured in 62 orchards in two years. The original spectra and the continuum- removed spectra are analyzed and correlated with SPAD values. The continuum-removed spectral indices of DVI (difference vegetation index), RVI (ratio vegetation index) and NDVI (normalized difference vegetation index) are calculated by the combination of arbitrary two bands in the range from 350 nm to 1300 nm. The stepwise regression and principal component analysis methods are used to extract the principal components as the independent variables. A support vector machine regression model for estimation of SPAD values is constructed and verified by the data collected in the second year. The vegetation indices of the biggest correlation between SPAD and the three newly built vegetation indices are NDVI (406, 563), RVI (406,565) and DVI (646,695), and the correlation coefficient (r) reaches 0.677, 0.690 and 0.711, respectively. The support vector machine regression model is verified. Relative error of prediction (REP) is 1.190%, PR2 is 0.837 and relative percent deviation of prediction (RPDP) is 2.213. The continuum-removed method and building vegetation indices can improve the correlation between spectra and apple canopy SPAD values. The spectral index which has the highest correlation with SPAD is composed of the visible bands. The support vector machine regression model has excellent ability to estimate the SPAD values of apple canopies which are growing rapidly.