地面高光谱和低空遥感监测小麦白粉病初探

The primary research of detecting wheat powdery mildew using in-field and low altitude remote sensing

利用手持式高光谱仪和基于数字技术的低空遥感系统,对不同严重度小麦白粉病冠层光谱反射率进行了测定,同时调查病情指数,分析不同时期地面平台光谱反射率与病情指数及低空遥感平台反射率与病情指数(diseaseindex,DI)、归一化植被指数(normalizeddifferencevegetableindex,NDVI)相关性。结果表明,地面光谱测量冠层光谱反射率和低空遥感数字图像反射率与小麦白粉病病情指数在灌浆期有显著的相关关系,就地面测量结果而言,近红外波段的相关性高于绿光波段,相关系数分别为0.79和0.54;低空遥感数字图像红、绿、蓝三波段中,相关性依次降低,相关系数分别为0.79、0.75和0.62;而且低空遥感图像与归一化植被指数也存在较好的相关关系,蓝、红、绿波段,相关系数依次为0.70、0.68和0.54。这表明利用遥感非破坏性监测小麦白粉病有着良好的应用前景,对于小麦白粉病发生面积监测有重要意义。

Using ASD hand-held spectroradiometers and low altitude remote sensing system measured the canopy reflectance of wheat damaged by Blumeria graminis f. sp. tritici and, at the same time, scored the disease index （DI）. The correlation between reflectance and DI and normalized difference vegetable index （NDVI） and DI was calculated. The results show that the correlation between reflectance and DI is significant at the stage of grouting. The result of in-field measurement shows that the correlation between near infrared reflectance and DI is higher than that of green band with the correlation coefficients of 0.79 and 0.54, respectively. The reflectance correlation between red, green and blue bands decreased in the order with the correlation coefficients of 0.79, 0.75 and 0.62, respectively. The reflectance of low altitude remote sensing was well correlated with NDVI moreover. The correlation coefficients are 0.70, 0.68 and 0.54 for blue, red and green band, respectively. This indicates that it is prospective in using remote sensing to monitor the development of wheat powdery mildew in the fields non-destructively and helpful in the investigation of occurrence area of the disease.