基于舰船噪声线谱特征的ETAM方法仿真研究

拖曳线列阵的方位分辨率是一项重要性能指标,而它被拖曳线列阵的阵列孔径所限制。针对这一问题,文中提出了基于舰船噪声线谱特征的ETAM方法,利用舰船噪声在低频段的稳定线谱成份,采用ETAM被动合成孔径算法扩展拖曳线列阵的孔径,从而达到显著提高方位分辨率的目的。只要ETAM的积分时间小于海洋声信道的时间相关长度,可将拖曳线列阵的等效孔径扩展到不大于海洋声信道的空间相关长度的任意尺寸。经仿真实验验证,该方法是有效的、可行的,且算法简单、易于实时实现,是一种具有良好应用前景的高分辨方位估计方法。

The Simulation Research on the ETAM Method Based on the Line-spectrum Features of the Ship Noise

The direction-of-arrival resolution of the towed linear array is an important performance index, which is restricted by the array aperture of the towed linear array. Aming at this problem, this paper has raised out the ETAM method based on the line-spectrum features of the ship noise. This method uses the stable part of the line-spectrum of the ship noise in the low frequency band, and uses the ETAM passive synthetic aperture algorithm to expand the aperture of the towed array. Thus the direction-of-arrival resolution can be improved greatly. If the integral time of the ETAM is smaller than the time correlative length of the ocean acoustic channel, it can expand the equivalent aperture of the towed array to any length, which is smaller than the space correlative length of the ocean acoustic channel. Proven by simulation, this method is useful and practical, and the algorithm is also easy and simple to carry out. It is a high-resolution direction-of-arrival estimation, which has a very good appliance perspective.