基于重叠互相关器的合成孔径水池实验研究(英文)

Overlap correlator based synthetic aperture processing test in water tank

在过去十几年里,为了增加拖曳线列阵系统的空间增益、提高方位分辨率,各种合成孔径技术应运而生。针对AUV舷侧阵系统水下目标远程探测的研究需要,给出了基于重叠互相关器的合成孔径处理算法(OCSAP),这种方法是在假设AUV旁侧阵匀速直线航行前提下,通过在波束域利用FFT变换合成孔径,并且在连续的时间间隔内对子孔径信号进行相关处理来实现的。在对该算法进行计算机仿真研究的基础上,在消声水池中进行了8阵元合成48阵元以及单阵元合成8阵元的逆合成孔径实验研究,两种实验结果均验证了OCSAP算法的有效性和可行性。实验结果表明合成孔径处理与常规物理孔径处理相比具有较好的鲁棒性,并且在接收信号时域相关长度大于合成孔径所需时间的水下或海洋环境里,合成阵增益与等长的物理阵增益基本相等。

Various synthetic to increase array spatial gain aperture techniques have been and improve bearing resolution investigated during the past decades for towed line array system. Aiming at the goal of flank array long-range underwater target detection for the autonomous underwater vehicles （AUV） system, an overlap correlator based synthetic aperture processing （OCSAP） algorithm is introduced, which synthesizes apertures in the beam domain using FFT and performs coherent processing of subaperture signals at successive time intervals on the assumption that AUV moves along a straight line at constant speed. On the basis of computer simulation for OCSAP algorithm, an inverse synthetic aperture experiment of 8 array elements synthesizing 48 sets, and one element synthesizing 8 sets were made in the water tank. Both results all testify the effectiveness and feasibility of OCSAP algorithm. Experimental results show that the synthetic aperture processing possesses better robustness than the physical aperture processing and, for underwater or ocean environments with received signals having temporal coherence longer than the synthetic aperture processing time, a synthetic array gain is equivalent roughly to a physical array with the same length.