Yugao Li, Guangzhen Bao, Jianming Hu, Xiyang Zhi, Tianyi Hu, Junjie Wang, Wenbo Wu
With the rapid growth of the marine economy and the increasing demand for maritime security, ship target detection has become critically important in both military and civilian applications. However, in complex remote sensing scenarios, challenges such as visual similarity among ships, subtle inter-class differences, and the continual emergence of new categories make traditional closed-world detection methods inadequate. To address these issues, this paper proposes an open-world detection framework for remote sensing ships. The framework integrates two key modules: (1) a Fine-Grained Feature and Extreme Value-based Unknown Recognition (FEUR) module, which leverages tail distribution modeling and adaptive thresholding to achieve precise detection and effective differentiation of unknown ship targets; and (2) a Joint Optimization-based Incremental Learning (JOIL) module, which employs hierarchical elastic weight constraints to differentially update the backbone and detection head, thereby alleviating catastrophic forgetting while incorporating new categories with only a few labeled samples. Extensive experiments on the FGSRCS dataset demonstrate that the proposed method not only maintains high accuracy on known categories but also significantly outperforms mainstream open-world detection approaches in unknown recognition and incremental learning. This work provides both theoretical value and practical potential for continuous ship detection and recognition in complex open environments.