Chenhao Zhu, Xueli Xie, Jianxiang Xi, Xiaogang Yang
Infrared object detection is an important prerequisite for small unmanned aerial vehicle (UAV) swarm countermeasures. Owing to the limited imaging area and texture features of small UAV targets, accurate infrared detection of UAV swarm targets is challenging. In this paper, the GM-DETR is proposed for the detection of densely distributed small UAV swarm targets in infrared scenarios. Specifically, high-level and low-level features are fused by the Fine-Grained Context-Aware Fusion module, which augments texture features in the fused feature map. Furthermore, a Supervised Sampling and Sparsification module is proposed as an explicit guiding mechanism, which assists the GM-DETR to focus on high-quality queries according to the confidence value. The Geometric Relation Encoder is introduced to encode geometric relation among queries, which makes up for the information loss caused by query serialization. In the second stage of the GM-DETR, a long-term memory mechanism is introduced to make UAV detection more stable and distinguishable in motion blur scenes. In the decoder, the self-attention mechanism is improved by introducing memory blocks as additional decoding information, which enhances the robustness of the GM-DETR. In addition, we constructed a small UAV swarm dataset, UAV Swarm Dataset (USD), which comprises 7000 infrared images of low-altitude UAV swarms, as another contribution. The experimental results on the USD show that the GM-DETR outperforms other state-of-the-arts detectors and obtains the best scores (90.6 on AP75 and 63.8 on APS), which demonstrates the effectiveness of the GM-DETR in detecting small UAV targets. The good performance of the GM-DETR on the Drone Vehicle dataset also demonstrates the superiority of the proposed modules in detecting small targets.