Burst模式在多波束声呐高帧率测深方法中的应用

The application of Burst mode in method of the multi-beam high frame rate bathymetry

在常规多波束测深声呐系统中,需要等待远距离目标信号到达接收基阵后才能再次发射探测信号,这将导致测深帧率下降。针对该问题,该文提出了一种基于Burst模式的多波束声呐高帧率测深方法。由于各角度的海底回波持续时间远小于远距离目标信号到达接收基阵的所需时间,根据这一特性,采用Burst模式,通过等间隔地发射多帧信号并接收,同时保证发射的间隔大于最大波束持续时间,实现多帧信号在时间角度域中的分离,提高测深系统帧率。由于相邻帧的隧道效应会与部分波束发生重叠,针对该问题采用改进的线性约束最小方差算法,实现了低副瓣宽零陷的波束形成,从而削弱隧道效应的影响。最后通过仿真数据验证了该文所提方法的有效性,表明该方法在特定条件下能够将测深帧率提高3.3倍。

In the conventional multi-beam bathymetry system,it is necessary to wait for the remote target signals to reach receiving array before re-launching the probe signals,which leads to the decrease of the bathymetry frame rate.In terms of this issue,a method of the multi-beam high frame rate bathymetry is proposed on the basis of Burst mode.The duration of the submarine echo at each angle is much less than the time required for the remote signals arrival.According to this feature,the Burst mode is adopted which transmits multiple frames of signals at equal intervals and then receives them,ensuring that the transmission interval is larger than the maximum beam duration simultaneously.It can realize the separation of multiframe signals in the time and angle domain,and improve the frame rate of the bathymetry system.Since the tunnel effect of adjacent frames will overlap with some part beams,an improved linearly constrained minimum variance beamforming algorithm is used to weaken the influence of tunneling effect,which realizes beamforming with low sidelobe and broad null.Finally,the effectiveness of the method proposed in this paper is verified by simulation data,which shows that the method can increase the bathymetry frame rate by 3.3 times under certain conditions.