Progressive Semantic Enhancement Network for Hyperspectral and LiDAR Classification

The joint classification of hyperspectral image (HSI) and light detection and ranging (LiDAR) data is gaining attention for its improved classification accuracy. However, effectively integrating the rich spectral information of HSI and the elevation features of LiDAR has remained a challenge in multimodal fusion. This article proposes a novel approach called progressive semantic enhancement network (PSENet) for hyperspectral and LiDAR classification based on a progressive joint spatial-spectral attention mechanism. PSENet mainly comprises two modules: the spatial grouping constraint (SAGC) module and the spectral weighting constraint (SEWC) module. The SAGC module extracts multiscale features in the spatial domain, while the SEWC module focuses on enhancing semantic features in spectral dimension. By gradually utilizing spatial and spectral constraint modules to progressively enhance feature extraction, PSENet integrates affluent information for a more refined classification of ground objects. Based on experimental results, it has been demonstrated that PSENet outperforms several most advanced methods on three datasets. The SAGC and SEWC modules proposed in PSENet enable the effective integration of the spatial, spectral, and elevation information from HSI and LiDAR, providing a promising way to perform classification more accurately. The source codes of this work will be publicly available at http://szu-hsilab.com/.