基于时频面霍夫变换的谐波族检测算法

Harmonic Detection Arithmetic Based on Hough Transformation in Time-frequency Domain

由声学方法进行直升机等目标的探测时,以往算法大多没有充分利用其谐波性质。针对此问题,提出了基于时频面霍夫变换的谐波族检测方法。使用谐波小波变换方法求得含噪声谐波族信号的时频分布,并进行Hough变换;基于频率分集融合处理技术将各阶谱线在变换域的强度综合,作为对目标的检测量。仿真计算结果表明,该方法能准确检测出谐波族信号基频及其变化率,并在信噪比较低时依然提供幅度较高的检测量,具有较好的应用前景。

To improve the detection capability for propeller-driven military targets such as helicopter, unmanned aerial vehicle and anti-submarine aircraft, making use of the harmonic property of their noise signal is an effective way. The harmonic signal set is processed by using the timeqrequency distribution based on the harmonic wavelet transformation algorithm and also by using the Hough transformation algorithm. The relationship between the parameters of the Hough transformation and parameters of the harmonic signal set is deduced under situation of stable or linear shifting frequency. Algorithm of searching the base frequency is established. Simulation results show that this algorithm can accurately detect the base frequency and the shifting rate of the harmonic signal set, and provide good detection ability under low SNR.