ISAR Technique for Inland Waterway Surveillance Using Spaceborne Single-Channel SAR Data

This paper proposes an inverse synthetic aperture radar (ISAR) technique specifically tailored for inland waterway surveillance using single-channel spaceborne SAR data. The approach delivers well-focused vessel images on a homogeneous plane, enabling reliable size estimation and supporting automatic target recognition. In addition, it jointly estimates vessel kinematic parameters, including speed and heading, and corrects azimuthal displacement to recover the actual vessel position. A key novelty lies in exploiting the elongated structural characteristics of ships for their positioning without relying on along-track interferometry, multi-platform acquisitions, or wake detection. Comprehensive theoretical and numerical performance analyses are presented under different use cases. The proposed method is further validated using real SAR data acquired over different waterways and vessel types, demonstrating robust performance and practical applicability across a wide range of operational scenarios relevant to inland traffic.