宽带分裂波束探鱼仪目标方位估计方法

DOA estimation method for wideband split-beam fish finders

目标方位估计是分裂波束探鱼仪的主要任务。常用的宽带目标方位估计方法包括互相关、互功率谱和自适应滤波。探鱼仪回波中存在大量目标,当鱼体目标回波时间间隔较小造成回波重叠时,这类方法会产生较大误差。本研究针对使用线性调频信号的宽带分裂波束探鱼仪,分析了信号时延对脉冲压缩结果的影响,提出一种利用脉冲压缩相位进行目标方位估计的方法,并给出理论推导。该方法运算量小,易于工程实现。仿真结果表明:该方法在目标间距不小于脉冲压缩距离分辨率时,仍然可以获得较为准确的方位估计;该方法与常用的互相关、互谱法相比,有更好的抗噪声能力。

DOA (Direction of arrival) estimation is the primary function of split-beam fish finders.Commonly used wideband DOA estimation methods include cross-correlation,cross-power spectrum and adaptive filtering.However,when the echo overlap occurs due to small fish spacing,there are significant errors in these methods.In this paper,a method of DOA for wideband split-beam fish finder is proposed by using LFM signal pulse compression technique,and the relevant theoretical derivation is provided.This method is computationally small and easy to implement.Simulation results show that this method can provide accurate DOA estimation when the target spacing is greater than the distance resolution of the fish finder,and has good noise resistance.