多普勒频移和干涉谱联合的水声目标运动参数估计

常见水中运动目标会辐射连续谱噪声和线谱噪声,连续谱噪声在浅海波导环境中形成明暗相间的干涉条纹。根据干涉条纹可以得到目标最近距离与速度的比值,无法直接解出两个参数值。针对利用干涉条纹无法分别估计最近距离与速度问题,提出一种多普勒频移、干涉条纹结合的运动参数估计方法。根据单条线谱多普勒频移得到最近距离与速度参数耦合曲线,再将该曲线与干涉条纹得到参数比值线相交,交点即为两参数估计结果。数值仿真估计声源运动速度、最近距离,在信噪比6 dB条件下,平均估计误差分别为0.71%与0.87%。将该方法应用在2021年6月大公岛海域海试数据,5组实验数据估计目标运动速度、最近距离平均误差分别为2.5%,4.4%,证明了方法的有效性。

Estimation of motion parameters of underwater acoustic targets by combining Doppler shift and interference spectrum

Common moving targets in water radiate continuous spectrum noise and linear spectrum noise, and continuous spectrum noise forms interference fringes between light and dark in a shallow waveguide. According to the interference fringe, the ratio of the range at the closest point of approach to the speed can be obtained, but the two parameter values cannot be solved directly. Aiming at the problem that the speed and the range at the closest point of approach cannot be estimated separately by interferometric fringes, a motion parameter estimation method combining Doppler frequency shift and interference fringes is proposed. The parameter coupling curve of the speed and the range at the closest point of approach is obtained according to Doppler frequency shift of single line spectrum. Besides, the parameter ratio line can be obtained by the interference fringe. And the two-parameter estimation result can be illustrated by the intersection point of these two curves. Numerical simulation estimates the speed and the range at the closest point of approach of the sound source, and the average estimation error is 0.71% and 0.87% under the condition of the signal to noise ratio of 6dB respectively. The method was applied to the sea experiment data of Dagong Island in June 2021, and the average errors of the target motion speed and the range at the closest point of approach were estimated to be 2.5% and 4.4% respectively, which proved the effectiveness of the method.