逆合成孔径处理技术的水池实验

The AUV-based Inverse Synthetic Aperture Processing in Water Tank

近年来随着海洋开发及现代高技术条件下海战要求的不断提高,基于合成孔径技术的水下无人航行器(Autonomous Underwater Vehicle,AUV)目标感知技术研究成为信号处理领域的研究热点之一。针对AUV有限的空间尺和水下航行的特点,给出了基于重叠互相关器阵的聚焦合成孔径处理算法,通过利用重叠阵元冗余的相位信息有效补偿了因运动造成的相位偏差,使得阵列能够同相叠加输出,有效的扩展了孔径。计算机仿真结果以及随后在消声水池中进行的逆合成孔径实验验证了算法的有效性。结果表明:在空间相关长度大于合成孔径长度以及信号时间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。

With the increasingly development of the requirements for the sea exploitation and naval battle under high technology, the bearing estimation techniques based on the synthetic aperture technique for autonomous underwater vehicle （AUV） become one of the hottest research topic in the field of signal processing. Aim at the limited size and navigational characteristic in underwater for AUV, a focused synthetic aperture processing algorithm based on the overlapped-correlator-array（OCA） is introduced. The outputs of array can be added with same phase by compensating the phase errors effectively caused by the motion of AUV after using redundant phase information of overlapped array elements, which extend apertures of array effectively. The results of computer simulation and an inverse synthetic aperture experiment made in the water tank testify the validity of the algorithm. Experiment showed that for underwater or ocean environments with spatial coherence longer than the synthetic aperture length and for signals with temporal coherence longer than the required acquisition time, a synthetic array gain is equivalent roughly to a physical array with same length.