不同种植设施背景蔬菜作物无人机高光谱精细分类

Fine classification of vegetable crops covered with different planting facilities using UAV hyperspectral image

中国蔬菜产业规模大、产值高,是促进农民增收和农村农业经济发展的支柱产业。快速准确地获取区域尺度蔬菜种植结构信息对于农业现代化、自动化和精细化等具有重要意义。无人机高光谱遥感技术具有快速机动灵活和“图谱合一”的优势,在作物精细分类中具有广泛应用前景。然而蔬菜作物种植规模差异大、农业景观破碎度高,同时还受地膜、大棚和防鸟网覆盖等影响,无人机高光谱图像易产生严重的混合光谱效应,给蔬菜作物精细分类带来了极大的挑战。针对此问题,本研究以湖南省农科院高桥科研基地蔬菜种植区为例,获取无人机高光谱图像,探索采用支持向量机和深度学习方法对不同蔬菜作物进行精细分类。研究结果表明:基于无人机高光谱遥感数据,可以实现不同覆盖背景下的蔬菜作物精细分类;两大分类方法的平均总体精度分别为78.03%和90.75%,平均Kappa系数分别为0.7359和0.8887,相较于支持向量机方法,基于深度学习的分类方法获得的精细分类效果更加理想,三维卷积神经网络和引入注意力机制的卷积神经网络可以有效提取图像中的光谱—空间特征信息,在蔬菜作物精细分类中体现出更好的分类效果;蔬菜作物在大尺度地块上空间纹理特征明显,而在小地块尺度上差异较大,宜采用不同深度学习方法对其进行精细分类;不同覆盖背景与蔬菜作物产生混合光谱效应,对作物精细分类效果影响显著。

features of images and obtain high-level and rich semantic information of samples to successfully complete the classification task.Therefore,SVM and Deep Learning(DL)methods were applied to the classification of vegetable crops in this study.Unlike other hyperspectral classification verification experiments that randomly select training sets,training and test samples were manually selected in this study to reduce the spatial correlation between training and test sets,and the performance of different classification methods was evaluated using confusion matrix.The results showed that based on hyperspectral images obtained by UAVs,the average overall accuracy of vegetable crop classification using SVM and DL methods is 78.03%and 90.75%,respectively,and the average Kappa coefficients are 0.7359 and 0.8887,respectively.Compared with the SVM methods,the fine classification effects obtained by the DL methods are more ideal.This finding is attributed to the effective extraction of spectral and spatial feature information from the image using the three-dimensional convolutional neural network and the convolutional neural network with attention mechanism,thus demonstrating a superior performance in the classification of vegetable crops.The spatial texture characteristics of vegetable crops are observed on large-scale plots,while they are various on small-scale plots.Thus,using different DL methods for the classification of vegetable crops on different scale plots is appropriate.Vegetable crops under different planting facilities were classified in this study using UAV hyperspectral images.Under the influence of complex backgrounds such as plastic films,bird nets,and greenhouses,satisfactory performance was still achieved using SVM and DL methods,which can provide technological support for the modernization,automation,and refinement of regional vegetable crop management.