A Fine PolSAR Terrain Classification Algorithm Using the Texture Feature Fusion Based Improved Convolutional Autoencoder

In order to more efficiently mine the features of polarimetric synthetic aperture radar (PolSAR) and establish a more appropriate classification model, this article proposes an improved convolutional autoencoder (ICAE) based on texture feature fusion (TFF-ICAE) for PolSAR terrain classification. Firstly, TFF-ICAE specifically designs a multi-indicator squeeze-and-excitation (MI-SE) block and incorporates it into the CAE network. MI-SE can enhance the essential feature information while suppressing the interference information as much as possible, and it can effectively increase the between-class distance while reducing the within-class distance. Then, TFF-ICAE uses gray level co-occurrence matrix (GLCM) to capture the texture features, and it optimally fuses these texture features and the deep features extracted by ICAE to complete the multi-level feature fusion, elevating the feature representation completeness of the terrain. That is, TFF-ICAE effectively enhances the feature separation capability of different categories while greatly elevating the feature representation completeness. Experiments on the data sets of San Francisco, Oberpfaffenhofen and Flevoland show that the proposed TFF-ICAE respectively achieves overall accuracies of 93.44%, 97.61% and 97.78%, which are at least 0.92%, 1.52% and 0.97% higher than other algorithms. Undoubtedly, the superiority of TFF-ICAE is verified on these data sets.