基于连续波信号的穿墙雷达探测系统凭借其低廉的成本、简单的结构以及优秀的静态杂波抑制等诸多优势,无论是在军事还是民用领域都受到人们广泛的关注。其中,直达波抑制以及检测过程中的虚假目标识别过滤问题一直是实现连续波穿墙雷达高精度定位的关键技术。针对传统连续波穿墙雷达在上述问题处理上的不足,提出了一种利用负反馈环路实时对消回波信号中的直达波分量,同时根据预先估测的窗函数内噪声幅值大小,自适应地调节系统阈值以去除检测过程中虚假目标的恒虚警检测方法,对雷达性能进行改进。最后用模拟实验的方法验证了提出技术对隐藏在墙后运动目标的检测跟踪能力。实验结果表明,采用提出的新技术对目标进行定位,实时性好,检测精度高,具有较高的实用价值。
In both military and civil fields,continuous-wave through-wall radar (CW-TWR) has been attracting people's extensive attention because of its obvious advantages, such as low cost, compact structure and outstanding static clutter sup- pression ability. The problems of direct wave suppression and fake target identification and filtering in the detection process have been the key issues to realize high accuracy localization with CW-TWR. Aiming at the shortcomings of traditional CW-TWR in dealing with above problems ,in this paper,a constant-false-alarm-rate detection method is proposed; using a negative feedback loop,the CFAR method can cancel the direct wave component in echo signal in real-time; at the same time,the CFAR algorithm automatically adjusts the system threshold according to the predicted noise amplitude in time window function, removes the fake targets in detection process and improves the radar performance. In the end of the pa- per ,experimental simulation results validate the effectiveness of the proposed technology ,which can be applied for tracking and locating the moving targets behind walls. Experiment results also show that the proposed technology features real-time locating ,high detection accuracy ,and has great value for practical applications.