Three-Channel Convolutional Neural Network for Polarimetric SAR Images Classification

Terrain classification is an important topic in polarimetric synthetic aperture radar (PolSAR) image processing and interpretation. A novel PolSAR classification method based on the three-channel convolutional neural network (Tc-CNN) is proposed and this method can effectively take the advantage of unlabeled samples to improve the performance of classification with a small number of labeled samples. Several strategies are included in the proposed method. First, in order to take the advantage of unlabeled samples, a data enhancement method based on the neighborhood nearest neighbor propagation method is proposed to enlarge the number of labeled samples. Second, to increase the role of central pixel in convolutional neural network classification based on the pixel, a spatial weighted method is proposed to increase the weight of central pixel features and weak the weight of other types of pixel features. Third, a specific deep model for PolSAR image classification (named Tc-CNN) is proposed, which can obtain more scale and deep polarization information to improve the classification results. The experimental results show that the proposed method achieves a much better performance than the existing classification methods when the number of labeled samples is few.