A 3D InISAR Imaging Method for Squint-Looking Compact Multi-Channel Radar System

When employing the 3D Inverse Synthetic Aperture Radar (ISAR) technique, the accuracy of the target reconstruction is significantly influenced by baseline length. In cases involving missile-borne radar, the baseline length is severely constrained by the size of the carrier platform, leading to a deterioration in imaging quality. Especially if the measurement is affected by the noise, a slight noise can cause great damage to the result. To solve this problem, we develop a squint Interferometric ISAR (InISAR) imaging method for compact multichannel radar system with short baselines under low Signal-to-Noise Ratio (SNR) environments. Firstly, subarray signals are synthesized to get radar echoes with higher SNR. At the same time, the baseline length also increases relative to the array element spacing. Cross-range scaling and peak extraction are then employed to acquire the initial range and azimuth information. Finally, the interferometric technique combined with coordinate transform (CT) and iterative operation is used to obtain the height information and correct image distortion. The proposed method can better the reconstruction result of the target for short baselines antenna configuration with the influence of noise. Numerous simulations have been conducted to verify the effectiveness of the proposed method.