基于时延和相位估计的改进位移相位中心算法

多接收元合成孔径声纳是当前研究的热点问题,偏航和侧摆是影响多接收元合成孔径声纳成像质量的关键因素。在深入分析位移相位中心算法的基础上,提出了一种改进的多接收元合成孔径声纳运动补偿算法。改进算法首先修正声信号的实际传播距离与采用等效相位中心近似的传播距离之间的偏差,然后基于时延和相位估计偏航和侧摆,而且改进算法消除了目标回波的相互干涉对估计运动误差的影响,从而在扩大了算法适用的运动误差范围的同时,提高了运动误差估计的精度。计算机仿真结果表明,改进算法有效地补偿了运动误差,改善了成像质量。

Improved Displaced Phase Center Algorithm Based on Time-delay and Phase Estimations

The image reconstruction of a multi-hydrophone SAS (Synthetic Aperture Sonar) has been an active research topic at present. Yaw and sway are the key factors which result in distorted image and loss of resolution. Based on the deep study of displaced phase center algorithm, an improved movement error estimation algorithm for multi-hydrophone SAS was proposed. With this method, the difference between the actual path length and the approximated path length using equivalent phase center was revised, and the yaw and sway were estimated utilizing the time-delay and phase estimations. The effect of echo interference on estimation was avoided by the improved algorithm. Through these ways, the movement error scope that could be estimated was extended and the accuracy of movement error estimation was improved. Simulation results show that the improved algorithm estimates the movement error effectively and the imaging quality is enhanced.