Remote sensing image matching is the basis upon which to obtain integrated observations and complementary information representation of the same scene from multiple source sensors, which is a prerequisite for remote sensing tasks such as remote sensing image fusion and change detection. However, the intricate geometric and radiometric differences between the multimodal images render the registration quite challenging. Although multimodal remote sensing image matching methods have been developed in recent decades, most classical and deep learning based techniques cannot effectively extract high repeatable keypoints and discriminative descriptors for multimodal images. Therefore, we propose a two-step “detection + matching” framework in this paper, where each step consists of a deep neural network. A self-supervised detection network is first designed to generate similar keypoint feature maps between multimodal images, which is used to detect highly repeatable keypoints. We then propose a cross-fusion matching network, which aims to exploit global optimization and fusion information for cross-modal feature descriptors and matching. The experiments show that the proposed method has superior feature detection and matching performance compared with current state-of-the-art methods. Specifically, the keypoint repetition rate of the detection network and the NN mAP of the matching network are 0.435 and 0.712 on test datasets, respectively. The proposed whole pipeline framework is evaluated, which achieves an average M.S. and RMSE of 0.298 and 3.41, respectively. This provides a novel solution for the joint use of multimodal remote sensing images for observation and localization.

Data-driven deep neural networks have demonstrated their superiority in high-resolution remote-sensing image (HRSI) classification based on superpixel-based objects. Currently, most HRSI classification methods that combine deep learning and superpixel object segmentation use multiple scales of stacking to satisfy the contextual semantic-information extraction of one analyzed object. However, this approach does not consider the long-distance dependencies between objects, which not only weakens the representation of feature information but also increases computational redundancy. To solve this problem, a superpixel-based long-range dependent network is proposed for HRSI classification. First, a superpixel segmentation algorithm is used to segment HRSI into homogeneous analysis objects as input. Secondly, a multi-channel deep convolutional neural network is proposed for the feature mapping of the analysis objects. Finally, we design a long-range dependent framework based on a long short-term memory (LSTM) network for obtaining contextual relationships and outputting classes of analysis objects. Additionally, we define the semantic range and investigate how it affects classification accuracy. A test is conducted by using two HRSI with overall accuracy (0.79, 0.76) and kappa coefficients ($\kappa$) (0.92, 0.89). Both qualitative and quantitative comparisons are adopted to test the proposed method’s efficacy. Findings concluded that the proposed method is competitive and consistently superior to the benchmark comparison method.