Dynamic Semantics-Guided Meta-Transfer Learning for Few-Shot SAR Target Detection

In complex and dynamic synthetic aperture radar (SAR) scenes, few-shot detection of novel classes suffers from sample scarcity and significant distribution differences between base and novel class features, leading to severe bias and poor generalization in existing few-shot object detection (FSOD) models. To address this issue, we propose a meta-transfer learning method based on dynamic semantic guidance (DSG). This approach combines the strengths of meta-learning and transfer learning, comprising three modules: semantic guidance (SG), distribution alignment metric (DAM), and global feature dynamic aggregation (GFDA). The SG module generates guided features with query semantic information to reduce the distribution gap between base and novel classes, dynamically adapting to few-shot novel class SAR targets. The DAM module applies adversarial training to achieve dynamic feature distribution alignment, improving model bias and generalization. The GFDA module dynamically aggregates and retains critical feature information, enhancing model detection performance. Experimental results on the SRSDD-v1.0, MSAR-1.0, and SAR-AIRcraft-1.0 datasets show that the DSG method outperforms state-of-the-art methods in the SAR field [Gaussian metafeature balanced aggregation (GMFBA)] and the optical domain [generalized FSOD(G-FSOD)], with average detection performance improvements of 1.21%, 1.45%, 1.44%, and 9.76%, 2.86%, 1.8%, respectively.

I. Introduction

Synthetic aperture radar (SAR) is an active remote sensing system capable of obtaining high-resolution images [1], [2], playing a crucial role in various aspects and being widely applied in national defense technology, disaster monitoring, ocean management, and other fields [3], [4], [5]. SAR target detection is an important part of SAR image interpretation tasks, and various SAR target detection methods have emerged, mainly divided into traditional methods [6], [7], [8], [9] and deep learning-based methods [10], [11], [12], [13], [14].