基于机载偏振-高光谱的小麦赤霉病精准探测机理与方法研究

In view of the low precision of crop disease monitoring by hyperspectral, the combination of airborne hyperspectral and polarization detection was used to monitor the wheat scab. The possibility to analyze the three-dimensional graph is explored, which is using the polarization information as an effective complement of the intensity information. This research focus on the following aspects: 1) Through the design and trial-manufacture of polarization accessory, the effective feature space will be expanded. The polarization accessory will be integrated with hyperspectral and miniature UAV. The method of obtaining crop information by combining airborne polarization and hyperspectral spectra will be proved. 2) The response relationship between polarization-hyperspectral characteristic information of wheat scab and other typical wheat fungal diseases under large-scale farmland environment will be studied, and the extraction and expression of corresponding characteristic parameters will be determined. 3) Based on the optimal combination of reflection intensity, color, texture, shape, spatial relationship and polarization features, an information fusion recognition model will be construct and a prescription map will be generated. The rapid identification of between different diseases, biological and abiotic stresses, and the degree of stress will be completed. The ability to identify the spectrum of "the same spectrum of different objects" and "the different spectrum of same objects" will be enhanced. Finally, the rapid and high-precision monitoring of wheat scab will be realized, which provides theoretical and method basis for scientific symptomatic drug application and establishment of a more accurate agricultural remote sensing expert system.

针对目前近地遥感监测小麦病害精度低的问题，将机载高光谱和偏振信息结合进行小麦赤霉病的精准探测，探索将偏振信息作为一种强度信息有效补充的三维图谱分析的可能性。重点研究：1）通过偏振附件的设计与试制以及与高光谱、微小型无人机的集成一体控制，拓展有效特征空间，探明机载偏振-高光谱图谱合一的作物信息获取方法；2）研究农田大尺度环境下，小麦赤霉病区别于其他小麦典型真菌病害的偏振-高光谱特征信息的响应变化关系，确定相应特征参量的提取与表达；3）在基于反射强度特征、颜色特征、纹理特征、形状特征、空间关系特征以及偏振特征等的优化组合下，构建信息融合识别模型并生成处方图。完成不同真菌病害之间、生物与非生物胁迫之间以及胁迫程度的精准快速鉴别，增强对“异物同谱”和“同物异谱”问题的谱图辨识能力。最终实现对小麦赤霉病的快速高精度监测，为科学对症施药，建立开发更为精准的农业遥感专家系统提供理论和方法依据。

我国是唯一小麦总产量超过1亿吨的国家，小麦的生产在我国粮食生产中举足轻重，小麦赤霉病产生以呕吐毒素为主的真菌毒素，食用后严重影响免疫力和生育力，直接对人畜健康和生命安全构成极大威害。本项目以小麦赤霉病为研究对象，研究了基于微小型机载高光谱结合偏振探测的方法监测小麦病害的新思路和新方法，突破近地遥感监测作物病害谱图信息分类识别精度低、时间滞后和普适性差的瓶颈。. 针对近地遥感监测小麦病害精度低的问题，将机载高光谱和偏振信息结合进行小麦赤霉病的精准探测，探索将偏振信息作为一种强度信息有效补充的三维图谱分析的可能性。重点研究：1）通过偏振附件的设计与试制以及与高光谱、微小型无人机的集成一体控制，拓展有效特征空间，探明机载偏振-高光谱图谱合一的作物信息获取方法；2）研究农田大尺度环境下，小麦赤霉病区别于其他小麦典型真菌病害的偏振-高光谱特征信息的响应变化关系，确定相应特征参量的提取与表达；3）在基于反射强度特征、颜色特征、纹理特征、形状特征、空间关系特征以及偏振特征等的优化组合下，构建信息融合识别模型并生成处方图。完成不同真菌病害之间、生物与非生物胁迫之间以及胁迫程度的精准快速鉴别，增强对“异物同谱”和“同物异谱”问题的谱图辨识能力。最终实现对小麦赤霉病的快速高精度监测，为科学对症施药，建立开发更为精准的农业遥感专家系统提供理论和方法依据。. 本项目的意义在于能够紧密围绕我国经济发展和粮食安全的迫切需求，侧重研究和解决保障大宗粮食作物增产丰产的重要应用领域的基础性问题。利用偏振-高光谱无人机近地遥感对小麦赤霉病进行评估，兼具两种探测器优势，对大范围、多时相监测小麦典型病害以及提高监测数据可靠性、稳定性和精准度具有重要意义。亦可推广至水稻等其他的作物生长过程的病害的早期精准监测和分级，在基于作物真菌病害监测技术领域，国内外尚无同类研究。