基于资源1号02D高光谱图像湿地水体分类方法对比——以白洋淀为例
A comparative study of water body classification of wetlands based on hyperspectral images from the ZY1-02D satellite: A case study of the Baiyangdian wetland
-
摘要: 水体是维持湿地的三要素之一,对其进行动态监测能够更好地保护湿地生态。传统的湿地水体监测采用实地测量或遥感图像人工解译方法,此类方法成本高、效率低,不利于连续动态监测。近年来,采用机器学习、深度学习等方法从卫星遥感图像中提取水体成为湿地水体监测的有效手段。因此,该文基于资源1号02D高光谱遥感图像,采用机器学习、神经网络和Transformer网络3类方法对白洋淀湿地水体进行分类,对比不同光谱预处理方法及训练使用不同图像邻域大小对水体分类准确率和计算效率的影响,探究湿地水体分类的最佳数据预处理方式和分类模型。结果显示,深度学习方法在分类精度和计算效率上均显著优于机器学习方法,尤其是基于光谱空间残差网络模型(spectral-spatial residual network,SSRN),在使用全谱段信息和9×9邻域大小时取得了最高分类精度(准确率达99.09%,召回率为99.62%,F1-score 为0.99)。此外,大气水汽吸收波段虽然信噪比较低,但仍包含重要信息,在模型训练和预测中使用该波段信息能够提升湿地水体分类精度。该研究成果有望为湿地水体分类的业务化操作提供方法支撑。Abstract: Water bodies serve as one of the three major elements in maintaining wetlands. Their dynamic monitoring can effectively protect wetland ecosystems. Conventional methods for monitoring water bodies in wetlands employ field surveys or manual interpretation of remote sensing images, which are costly and inefficient, and inapplicable to continuous dynamic monitoring. In recent years, using methods like machine and deep learning to extract water body features from satellite remote sensing images has developed into an effective means for monitoring water bodies in wetlands. Based on the hyperspectral images from the ZY1-02D satellite, this study classified the water bodies in the Baiyangdian wetland using machine learning, convolutional and transformer neural networks. The accuracy and computational efficiency of water body classification under different spectral preprocessing methods and different image neighborhood sizes in training were compared to explore the optimal data preprocessing method and classification model for water bodies in wetlands. The results indicate that deep learning significantly outperformed machine learning in classification accuracy and computational efficiency. In particular, the spectral-spatial residual network (SSRN) model based on the convolutional neural network achieved the highest classification accuracy (OA: 99.09 %, Recall: 99.62 %, F1-score: 0.99) under conditions of all spectral bands and a 9×9 neighborhood size. Besides, despite a low signal-to-noise ratio, the atmospheric water vapor absorption band contained significant information, assisting in improving the classification accuracy of water bodies in the wetland during model training and prediction. The results of this study are expected to provide methodological support for the business operation of water body classification of wetlands.
下载: