Wang Ruijia, Chen Jie, Wang Xing, Sun Bing
Aeronautics and Astronautics Engineering College, Air Force Engineering University, Xi'an 710038, China.
School of Electronics and Information Engineering, Beihang University, Beijing 100084, China.
Sensors (Basel). 2017 Jan 9;17(1):123. doi: 10.3390/s17010123.
Retransmission deception jamming seriously degrades the Synthetic Aperture Radar (SAR) detection efficiency and can mislead SAR image interpretation by forming false targets. In order to suppress retransmission deception jamming, this paper proposes a novel multiple input and multiple output (MIMO) SAR structure range direction MIMO SAR, whose multiple channel antennas are vertical to the azimuth. First, based on the multiple channels of range direction MIMO SAR, the orthogonal frequency division multiplexing (OFDM) linear frequency modulation (LFM) signal was adopted as the transmission signal of each channel, which is defined as a sub-band signal. This sub-band signal corresponds to the transmission channel. Then, all of the sub-band signals are modulated with random initial phases and concurrently transmitted. The signal form is more complex and difficult to intercept. Next, the echoes of the sub-band signal are utilized to synthesize a wide band signal after preprocessing. The proposed method will increase the signal to interference ratio and peak amplitude ratio of the signal to resist retransmission deception jamming. Finally, well-focused SAR imagery is obtained using a conventional imaging method where the retransmission deception jamming strength is degraded and defocused. Simulations demonstrated the effectiveness of the proposed method.
转发欺骗干扰会严重降低合成孔径雷达（SAR）的探测效率，并可能通过形成虚假目标来误导SAR图像的判读。为了抑制转发欺骗干扰，本文提出了一种新型的多输入多输出（MIMO）SAR结构——距离向MIMO SAR，其多通道天线垂直于方位向。首先，基于距离向MIMO SAR的多个通道，采用正交频分复用（OFDM）线性调频（LFM）信号作为每个通道的发射信号，将其定义为子带信号。该子带信号对应于发射通道。然后，所有子带信号用随机初始相位进行调制并同时发射。信号形式更加复杂且难以截获。接下来，利用子带信号的回波在预处理后合成宽带信号。所提方法将提高信号的信干比和峰幅比，以抵抗转发欺骗干扰。最后，使用传统成像方法获得聚焦良好的SAR图像，其中转发欺骗干扰强度降低且图像散焦。仿真结果证明了所提方法的有效性。
