Two-Dimensional Imaging Using Frequency Diversity with Inverse Synthetic Aperture

In this paper, a novel frame combining frequency diversity with inverse synthetic aperture is proposed. In this frame, the transmitted single frequency signals is selected among diverse frequencies at different observed time. These selected frequencies can synthesize a wideband signal, thus achieving a high distance resolution. And in the azimuth direction, the resolution can be obtained by the relative motion between the radar and the target. Therefore, the proposed frame has the ability of two-dimensional imaging for targets. For the proposed frame, furthermore, an ISAR imaging model based on synthetic wide-band signals is established, and an improved two-dimensional ISAR imaging algorithm based on the backward projection (BP) imaging algorithm is proposed. Simulation show that the improved two-dimensional ISAR imaging algorithm can obtain two-dimensional imaging of multiple moving targets. Therefore, from the perspective of applications, the proposed frame can reduce the hardware complexity and cost of transmitter/receiver when compared with the existing ISAR imaging systems.