3-D ISAR Imaging via Migration Through Azimuthal Angle Cell Compensation With Vortex Electromagnetic Wave Radar

With the capacity to carry the orbital angular momentum (OAM), the vortex electromagnetic wave (VEMW) radar observes targets from a unique dimension. Since the VEMW radar introduces the azimuthal angle information, it certainly extends the potential of 3-D inverse synthetic aperture radar (3-D ISAR) imaging. Nevertheless, the large rotational angle and OAM mode number limit the application of reconstructing noncooperative targets' spatial construction with high quality. To address it, this letter proposes a novel 3-D ISAR imaging method based on the migration through the azimuthal angle cells (MTAAC) compensation. First, we construct the MTAAC phase by forming and analyzing the rotational geometric model. Following that, the related MTAAC compensation phase is established. Then, we perform the CLEAN algorithm on the conventional ISAR image to estimate the range and cross-range of different scatterers. Finally, we iteratively extract the 3-D structure of the target by compensating the MTAAC within the VEMW ISAR image. The MTAAC domain is also provided to further confirm the condition and the coverage of the proposed method. The simulated experiments show that the proposed method achieves a 10.6% reconstruction error under 0-dB signal-to-noise ratio (SNR) scenarios, verifying the effectiveness of the proposed method.