广义互相关时延估计声定位算法研究

针对地面目标声定位因信噪比较低而定位精度差的现象,提出了基于广义互相关法的声定位系统,根据平面四元法目标定位计算式,研究了广义互相关算法在实际中的应用。环境噪声、军事目标声和民用目标声频谱范围大多集中,即出现目标声会与背景噪声高度重合的情况,发现一般加窗滤波法在降低噪声的同时亦会将目标声强度大大削弱,而广义互相关时延估计法是通过计算两路信号互相关函数的最大值而求得时延差,其精度高、稳定性好。通过计算机仿真得到在信噪比较低的情况下,加窗滤波因大大削弱目标声强度而造成定位精度较低,而利用广义互相关方法可得到较为精确的声定位坐标。

Study of a generalized cross-correlation time delay estimation based acoustic positioning algorithm

To solve the low precision problem of acoustic positioning for ground targets in low signal noise ratio （SNR）, this paper puts forward an acoustic positioning system based on the generalized cross-correlation method. The practical application of the generalized cross-correlation algorithm is studied according to the calculation formulas of the planar four-element array positioning method. Owing to the fact that the spectrums of environmental noise, military target drone and civilian target drone are possibly similar, using the general window filtering method to reduce noise could weaken the target acoustic intensity greatly. However, the high accuracy and good stability could be achieved by using the generalized cross-correlation time delay estimation method, in which the difference of time delay is obtained by cal-culating the peak of the cross-correlation function between the signals from two channels. In the low SNR condition, the computer simulations show that the adding filtering window method makes lower localization accuracy, but the use of the generalized cross-correlation method can get more precise positioning coordinates.