摘要
水声学中波导不变量的研究是近30年来引人注目的课题之一。水下目标辐射噪声的直达波和海面、海底反射波之间的干涉现象中隐含有下水目标的距离信息。提取这种距离信息就为水下目标的被动测距提供了一种新的途径。理论分析和实际海试都证明,甚至单水听器的LOFAR(Low Frequency Analysis Record)图都隐含着目标的距离和运动信息。本文给出利用波导不变量提取目标距离信息的理论推导,证明了在形成干涉条纹的外界条件具备时,利用多个水听器构成的基阵也能以较大增益提供目标距离信息。虽然组成基阵的每一水听器出现干涉条纹的条件是有差异的。这种差异在波束成形时可以加以利用和补偿。本文提出的理论和部分仿真、海试结果为水下目标被动测距和目标识别提供了一种新的途径。
The study of wave guide invariant in underwater acoustics is one of attracted topics in recent 30 years. The interferences of direct wave and reflect wave from sea surface and sea bottom of underwater target radiated noise inherent the information of target distance. Extraction of these distance information will provide a possible new way in passive ranging for underwater target. The theoretical analysis and the results of at sea experiments show that the LOFAR （Low Frequency Analysis Record） figure inherently contains the range and moving information of passive acoustic sources, even in the situation that the receiver is only one single hydrophone. The theoretical analysis of extraction of target distance information by using wave guide invariant is presented in this paper. It is shown that, based on the interference striation pattern of target, the hydrophone array system is possible to extract the distance information with quite high array gain. Although the mathematical constrain conditions in forming interference striation pattern are different for individual array element, but it is proved that the differences of time delays between array elements can be used in compensation of beamforming. The theoretical analysis, system simulation and some results of at sea experiment show a new way in passive ranging and target recognition.
出处
《声学学报》
EI
CSCD
北大核心
2015年第2期138-143,共6页
Acta Acustica
