Moving Target Coherent Integration Method Based on TRCM-KT for UAV-Mounted Through-the-Wall Radar

Moving target detection in through-the-wall scenario can be achieved by utilizing uncrewed aerial vehicle (UAV) radar. However, considering indoor human target detection, the distance between the radar and the moving target is relatively short, and the ratio of target's velocity to the UAV's velocity varies greatly, which makes the range migration and Doppler phase much more complex and poses huge challenges for coherent integration. To address this issue, this letter proposes a moving target coherent integration method based on time reverse conjugate multiply and keystone transform (TRCM-KT) for UAV-mounted through-the-wall radar. In the proposed method, the reference signal is constructed by azimuthal time reverse and conjugation. Then, by multiplying the echo signal and the reference signal, the second-order range migration and doppler phase terms are eliminated. Next, keystone transform is employed to correct the remained first-order range migration. Finally, the fully coherent integration results can be obtained by performing Fourier transform along the azimuth direction. The effectiveness of the proposed method is verified by both simulation and experiment results.

I. Introduction

Uncrewed aerial vehicle (UAV) mounted through-the-wall radar can be used to detect indoor moving human targets flexibly [1], [2], [3]. The performance of moving target detection is significantly affected by target energy coherent integration result. As is well known, coherent integration improves the signal-to-noise ratio (SNR) by compensating the phases across multiple pulse samplings [4], [5], [6].