Estimation of the rotation velocity and scaling for ISAR imaging of near-field targets based on the integrated generalized cubic phase function and image interpolation

Inverse synthetic aperture radar (ISAR) imaging of the near-field target is potentially significant with the development of radar technology. The near-field target cannot be mapped to the ISAR image correctly because it does not satisfy the far-field distance approximation. To efficiently solve the distortion problem, it is more desirable to estimate the rotation velocity for near-field ISAR imaging. In this article, we propose a method for estimating the rotation velocity of the near-field target based on integrated generalized cubic phase function. Different from the far-field target, the received signal of the near-field target in a range bin is considered as the cubic phase signal, and the rotation velocity can be determined by the coefficients of the cubic phase signal. Afterwards, we utilize the cubic convolution image interpolation to rescale the image on the homogeneous Cartesian domain. Experimental results of simulated data demonstrate the effectiveness of the proposed method on rotation velocity estimation and scaling of the near-field target.