A Translation Compensation Method for ISAR Based on Second-order WVD

‍ ‍Inverse synthetic aperture radar （ISAR） target imaging is widely used in military and civilian fields. In recent years， the development of ISAR target imaging technology has become more mature. However， due to the complex observation scene and the non-cooperative characteristics of the target， the acquired target image has low resolution and problems such as defocusing and smearing. In response to the above problems， this paper proposes an ISAR translation compensation method based on the second-order Wigner-viller Distribution （WVD）. Firstly， the ISAR echo signal is modeled as a second-order polynomial， and then the keystone transform is used to correct the range walk caused by motion. Secondly， the second-order WVD transform is used to focus the energy of all scatterers of the target， and then estimate the second-order motion parameters. Finally， the target image with good focus is obtained by demodulation and keystone transform. The proposed method has stable performance in low signal-to-noise ratio （SNR） environment， and avoids multi-dimensional search， and reduces the computational complexity， which is conducive to real-time imaging of ISAR moving targets.