A radar–vision fusion approach for ship monitoring in bridge waterways using weakly supervised cross-modal representation learning

Frequent ship–bridge collisions pose serious risks to infrastructure, public safety, and economic assets. Reliable ship perception is critical for timely risk identification in bridge waterways. Radar–vision fusion enables complementary ship sensing capabilities beyond single-sensor monitoring using cameras or radars alone. However, existing rule-based fusion methods exhibit limited applicability in continuous waterway monitoring due to poor generalisation and labour-intensive calibration. This study proposes a weakly supervised representation learning framework that achieves embedding-level alignment with reduced manual supervision to improve the robustness of radar–vision association-based ship monitoring. A time window-based pseudo-labelling strategy is introduced to guide a Transformer-based dual encoder for learning shared radar–vision representations, with a novel ordinal loss incorporated into contrastive learning to enforce physical consistency. The framework is validated on a real-world bridge waterway using a field-deployed radar–camera system, achieving an F1-score of 95.7% and outperforming state-of-the-art learning-based fusion methods in the traffic sensing domain. The proposed approach can provide reliable and automated situational awareness of bridge waterway traffic to support decision-making in navigational safety management systems.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 02004875
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 2 2026 4:54PM