Air Moving Target Imaging for Staggered ISAR

The rapid development of the modern electronic counter-countermeasures (ECCMs) has made the conventional inverse synthetic aperture radar (ISAR) associated with the regular signal waveforms more vulnerable and unreliable. To deal with this issue, the complex waveform designment with staggered pulse sampling is developed in an ISAR system in this letter. In the proposed method, the generalized time-scaled transform (GTST) is adopted to effectively accomplish the irregular signal reconstruction and linear phase decoupling. After that, a set of matched filtering functions are established and interspersed in the imaging processes to accomplish the subsequent motion compensation, target imaging, and range and cross-range scaling. Finally, a satisfied ISAR imagery corresponding to the real size of a moving target can be recovered. The simulation and real-measured radar data processing results are applied to demonstrate the effectiveness of the proposed method.

I. Introduction

Inverse synthetic aperture radar (ISAR) has been a well-consolidated solution for recovering the two-dimensional (2-D) high-resolution imageries of air noncooperative moving targets [1]–[3]. Unfortunately, the traditional radar waveforms become more and more vulnerable and unreliable with the rapid development of the modern electronic counter-countermeasures (ECCM) technique [4]. The signal sequence with random pulse repetition moments has received considerable attention deriving from its low probability of interception, high antijamming ability, high range and velocity resolution, and the efficacy to prevent velocity ambiguity, which is widely considered in the new-generation radar systems [5].