Abstract:A narrowband imaging method for space target with compound micromotion is proposed. Due to the advantages of narrowband radar in target detection and tracking, narrowband radar is widely used in space target detection. For space target with micromotion, there is timevarying Doppler modulation induced by micromotion, which contains the important structural information of the target. By applying the inverse Radon transform (IRT) method on the timefrequency image, the position of scattering centers of the target can be obtained and the narrowband imaging can be achieved. Narrowband imaging reduces the requirement of radar bandwidth and has advantages in space target detection. However, in the real detection scene, the target motion is composed of micromotion and translation, which makes the narrowband imaging method invalid. In this paper, based on the radar echo model of space target with compound micromotion, the timevarying Doppler modulation characteristics of the target are analyzed, and a narrowband imaging method for compound micromotion is proposed. Firstly, the micromotion period is estimated based on the timefrequency correlation coefficient. Then the translational influence is removed by the Doppler cancellation method, the target translational parameters are estimated, and then the translational compensation is achieved. Finally, the narrowband imaging is achieved based on the IRT. The proposed method is not affected by the target translation, and can effectively achieve the narrowband imaging for space target with compound micromotion.