Micro-Doppler effect removal for ISAR imaging based on bivariate variational mode decomposition

• Published in: IET radar, sonar & navigation sonar & navigation, 2018-01, Vol.12 (1), p.74-81
• Main Authors: Kang, Wenwu, Zhang, Yunhua, Dong, Xiao
• Format: Article
• Language: English
• Subjects: bivariate variational mode decomposition; BVMD method; common Doppler responses; complex‐valued mode functions; conventional range‐Doppler imaging algorithms; Doppler radar; high‐resolution imaging; image resolution; inverse synthetic aperture radar imagery; ISAR imaging; micromotions; micro‐Doppler effect removal; m‐D signatures; m‐Ms; parameter estimation; radar imaging; radar interferometry; Research Article; rotating parts; synthetic aperture radar; vibrating parts
• ISSN: 1751-8784; 1751-8792
• DOI: 10.1049/iet-rsn.2017.0104

Micro-Doppler (m-D) effect is caused by vibrations and/or rotations of mechanical components of moving targets. The m-D signatures corresponding to such micro-motions (m-Ms) may significantly degrade the usefulness of synthetic aperture radar/inverse synthetic aperture radar (ISAR) imagery. The strong echo of the main body of a target can make the m-D parameter estimation of the vibrating or rotating parts more difficult. The removal of m-D effect from target's ISAR image is thus very important for realising high-resolution imaging of a complex target involving m-M parts. To treat this problem, the bivariate variational mode decomposition (BVMD) is proposed to get rid of the m-D effect from the image of target's main body. The BVMD method first decomposes the radar echoes of range cells into a series of complex-valued mode functions according to which m-D signatures can be distinguished and removed from common Doppler responses. Finally, a refined ISAR image of the main body is produced using conventional range–Doppler imaging algorithms. Both simulated and real measured data are processed to show the effectiveness of the proposed method.