基于偏振二向性反射特性的南疆红枣偏振遥感机理研究

Xinjiang production and construction corps precision agriculture in the process of gradually realize informatization, digitization, an urgent need to quickly by remote sensing monitoring method for large area of red jujube quality. This project in southern xinjiang red jujube comprehensive digital model work, based on the two to explore polarization reflection characteristics to improve spectral resolution to improve the precision of remote sensing detection method. Experiments for jujube multi-angle polarization information and 2 to the reflection characteristics of the target spectrum, through the red jujube quality component spectra and the conditions of the field of zaoyuan canopy spectral statistical studies. In southern xinjiang red jujube multi-angle polarized light detection experiments, studies the changing rule of the red jujube reflex polarized direction information and detecting method. Use the combination of indoor and outdoor spectroscopy method, carry out quality and jujube jujube leaf spectra and jujube canopy spectral correlation research. In 224 and 14 NongYiShi 10 group two different geographical composition spectrum of red jujube jujube canopy spectral characteristics research and field conditions. Response spectrum and polarization and to explore the southern xinjiang red jujube reflection spectrum corresponding relation, according to the characteristics of southern xinjiang red jujube choose the best sampling method to build more optical parameters of polarization remote sensing database model, combined with the corresponding regional traffic for the research of polarization remote sensing monitoring models and mechanism. In southern xinjiang red jujube quality remote sensing monitoring for the future lay a theoretical foundation.

新疆兵团精准农业在逐步实现信息化、数字化过程中，迫切需要遥感监测南疆大面积红枣品质差异和变化等信息。本项目在开展南疆红枣综合数字化模型工作基础上，探索偏振二向反射特性提高光谱分辨率来提高遥感检测精度的方法。实验获取红枣偏振多角度信息和二向性反射目标物特征光谱，通过红枣品质的组分光谱和田间条件 枣园冠层光谱统计相关研究。开展南疆红枣偏正光多角度检测实验，研究红枣偏正方向 性反射信息的变化规律和探测方法。采用室内光谱和野外光谱相结合方法，深入开展红枣品质与枣单叶光谱和枣园冠层光谱相关关系的研究。在农十四师224团和农一师10团两个不同地域红枣的组分光谱及田间条件枣园冠层光谱特征研究。探索南疆红枣响应光谱和偏振及二向反射波谱对应关系，依据南疆红枣特征选取最佳的采集方法构建多光学参数偏振遥感数据库模型，结合相应地区遥感图开展偏振遥感监测模型和机理的研究。为今后开展南疆红枣品质遥感监测奠定理论基础。

南疆红枣品质近地面遥感检测，迫切需要提高检测模型精度和稳定性，项目组深入开展偏振探测机理和方法研究。通过多角度标准板校正和多角度光谱偏振态检测方法，结合典型环境温度和方位校正方法，提高南疆红枣监测模型预测精度和范围。首先通过不同颗粒尺度和折射率分布对散射强度方向分布规律的模拟仿真，研究随机强散射和弱散射介质的偏振反射和散射强度分布规律。其次，搭建近地面高光谱偏振检测和偏振二向色性检测系统，开展红枣多角度偏振反射和二向性反射（BRDF）实验，研究不同距离和角度方位红枣样品光谱偏振态变化规律，实验验证了偏振反射与二向性方向反射的定量关系。通过不同方位标准板建立红枣高光谱多角度偏振数据库，利用南疆红枣品质组分光谱偏振态变化与方位对应关系，进行室内组分光谱模型与高光谱多角度偏振方位模型传递。建立室内红枣高光谱偏振模型预测不同方位红枣品质。通过持续增加多方位光照和探测方向特征光谱数据，拟合修正多角度偏振BRDF特征模型参量，提高红枣样品BRDF特征模型方位角度适应性和稳定性。可用于更多精细方位检测，以实现从规则固定方位照明检测到随机光照方位红枣样品检测。最后，通过户外持续采集南疆10团，224团枣园的脆熟期，白熟期，完熟期等不同时期枣树冠层（0，45，90，135）四个偏振方向近地面高光谱偏振数据。大气校正和辐射标定等方法建立户外多环境参量红枣光谱库。典型环境温度模型库，高光谱正交偏振光谱库。提取偏振特征dolp,orient，获取不同方位和纹理特征的红枣光谱偏振特征信息。谱偏相关，谱像相关等方法，增强枣树冠层阴影和消减直射强光等复杂环境下高光谱图像细节信息。基于南疆枣园典型环境大数据驱动数据训练和光谱偏振态细分特征的数据库模型，为今后开展南疆枣园红枣品质偏振定量遥感奠定基础。可提取多偏振维度、多时相品质特征构建红枣品质监测体系。该成果在南疆其他特色果品如苹果，香梨等品质定量遥感方面也有重要的参考价值。