声学技术
聲學技術
성학기술
Technical Acousitics
2014年
5期
464-468
,共5页
时延估计%平面四元阵%广义互相关
時延估計%平麵四元陣%廣義互相關
시연고계%평면사원진%엄의호상관
time delay estimation%four-element plane array%generalized cross-correlation
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。
針對地麵目標聲定位因信譟比較低而定位精度差的現象,提齣瞭基于廣義互相關法的聲定位繫統,根據平麵四元法目標定位計算式,研究瞭廣義互相關算法在實際中的應用。環境譟聲、軍事目標聲和民用目標聲頻譜範圍大多集中,即齣現目標聲會與揹景譟聲高度重閤的情況,髮現一般加窗濾波法在降低譟聲的同時亦會將目標聲彊度大大削弱,而廣義互相關時延估計法是通過計算兩路信號互相關函數的最大值而求得時延差,其精度高、穩定性好。通過計算機倣真得到在信譟比較低的情況下,加窗濾波因大大削弱目標聲彊度而造成定位精度較低,而利用廣義互相關方法可得到較為精確的聲定位坐標。
침대지면목표성정위인신조비교저이정위정도차적현상,제출료기우엄의호상관법적성정위계통,근거평면사원법목표정위계산식,연구료엄의호상관산법재실제중적응용。배경조성、군사목표성화민용목표성빈보범위대다집중,즉출현목표성회여배경조성고도중합적정황,발현일반가창려파법재강저조성적동시역회장목표성강도대대삭약,이엄의호상관시연고계법시통과계산량로신호호상관함수적최대치이구득시연차,기정도고、은정성호。통과계산궤방진득도재신조비교저적정황하,가창려파인대대삭약목표성강도이조성정위정도교저,이이용엄의호상관방법가득도교위정학적성정위좌표。
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.