(1. 中南大学 地球科学与信息物理学院，长沙 410083；2. 中南大学 物理与电子学院，长沙 410083)
摘 要: 基于连续波信号的穿墙雷达定位系统凭借其低廉的成本、简洁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广泛关注。然而，连续波穿墙雷达的传统定位算法基于短时傅里叶分析，由于受限于算法所固有的时频分辨率折中矛盾，其探测精度通常较差。针对传统定位算法在时变低信噪比条件下检测精度低、虚警率高以及目标识别困难等缺陷，提出一种基于高阶模糊函数的目标定位新算法。该算法通过实时估测噪声的统计参数，自适应地对滤波器函数进行调整，实现在时变低信噪比条件下的恒虚警检测，抑制虚假目标的产生；此外，该算法还能基于回波的高阶模糊函数对多个目标分量进行高精度分离和参数估计，同时实现对多个目标的准确跟踪和定位。实验结果验证了新算法的有效性，证实其能够提供比传统算法更高的检测精度，为连续波穿墙雷达的高精度成像提供可能。
关键字: 连续波穿墙雷达；恒虚警检测；高阶模糊函数；CLEAN 算法
（1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. School of Physics and Electronics, Central South University, Changsha 410083, China）
Abstract:In both the military and civil areas, through wall radar based on continuous wave signals was attached people’s attentions because of its obvious advantages, such as low price, compact structure and outstanding ability of static clutter suppression. However, the corresponding detection accuracy of the traditional target localization algorithm, which is based on the short time Fourier transform (STFT), is usually poor because of the inherent tradeoff of the algorithm between time and frequency resolutions. A new target localization algorithm, which is based on the high order ambiguous function, is proposed to deal with the issues such as low detection accuracy, high false alarm rate and identification difficulties in time-varying low signal-to-noise ratio environments. The proposed algorithm can estimate the noise statistic coefficients in real time and adapt the filter function accordingly to maintain a constant false alarm rate and suppress the rise of the fake targets. Besides, this algorithm can achieve high accurate separation and parameter estimation to multiple signal components based on the high order ambiguous function of the echo, which can help observers accurately track and locate multiple targets. The experimental results verify the effectiveness of the new algorithm that larger detection accuracy can be afforded than the case when the traditional algorithm is used individually. The possibility for the high resolution imaging of the continuous-wave through-wall radar can be obtained with the new algorithm.
Key words: through wall radar; constant fake alarm rate; high order ambiguous function; CLEAN algorithm
