A Novel ISAR Imaging Scaling Approach for Maneuvering Targets Based on Monopulse Radar

Inverse Synthetic Aperture Radar (ISAR) imaging faces challenges in cross-range scaling for maneuvering targets due to nonuniform rotation, which complicates the estimation of rotational parameters. Though the traditional methods are theoretically effective, they are constrained by high computational complexity, thereby limiting real-time applications. Meanwhile, the monopulse technique, which is derived from monopulse radar and known for high angular measurement accuracy, has been integrated with ISAR to enhance imaging performance. However, traditional methods directly apply the monopulse technique after ISAR imaging, prone to inducing angle glint phenomena, which degrade the accuracy of scatterer projection. This paper innovatively integrates the monopulse technique into the ISAR imaging process and proposes a novel cross-range scaling method for maneuvering targets. By establishing a relationship between the monopulse angle and the ISAR equivalent rotation angle, the method decouples the estimation of Equivalent Rotation Velocity (ERV) and Equivalent Rotation Acceleration (ERA). Amplitude information is used to derive ERV, while phase information is utilized to obtain ERA, which significantly reduces computational complexity. The proposed algorithm offers high estimation accuracy and is well-suited for real-time, high-precision applications. Simulation results validate the effectiveness of the method and demonstrate its potential to enhance ISAR cross-range scaling for maneuvering targets.