本文主要讨论利用声场干涉现象由单水听器被动测距的可行性及测距性能,为此提出了单水听器波导不变量被动测距方法,通过提取LOFAR图上干涉条纹、使用简正波模型计算波导不变量、频域相关法估计相对速度,最后依据干涉条纹方程得到声源距离估计量。数值仿真和海上实验结果验证了单水听器被动测距的可行性,并具备一定测距性能,在3 dB信噪比环境中,对于7 km处的运动声源,平均测距误差小于5%。本文方法具有设备简单、易于推广至阵列信号处理等特点,为声纳信号处理环境宽容性的提高及环境适配声纳的设计开拓了思路。
A passive range estimation method using a single hydrophone based on waveguide invariant analysis was established. Interference striations were first extracted from LOFAR,the waveguide invariant and relative velocity was then calculated by normal mode and frequency-domain correlation,respectively. Finally range estimation was determined according to interference striation equation. Theoretical feasibility and ranging performance of the proposed method were verified using results of both numerical simulation and sea experiment. For a moving sound source at a distance of seven kilometers in 3 dB SNR environment,the average ranging error is less than 5%. This method requires simple equipments and can be easily applied to the array signal processing,thus extending the design model for environment adapted sonar with enhanced environmental tolerance.