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在利用高分辨率声纳探测水下或海底目标的方位时,由于使用了最大熵法(MEM)来分析空间频率,因此其分辨率得到了提高。模拟结果表明,当信噪比S/N大于或等于10dB时,用MEM法得到的方位分辨率大约是用FFT法进行传统的波束形成所得到的方位分辨率的二倍。此外,在作MEM分析之前,为了提高信噪比S/N和信号/混响比S/R,新设计了一种空间前置滤波器,用来对空间频率的带宽进行限制。研究证明,即使S/N为0dB时,也能获得较好的方位分辨率。
When using high-resolution sonar to detect underwater or submarine targets, the resolution is improved due to the use of the maximum entropy method (MEM) to analyze spatial frequencies. The simulation results show that the azimuth resolution obtained by the MEM method is about twice the azimuth resolution obtained by the traditional beamforming method using the FFT method when the S / N ratio is greater than or equal to 10 dB. In addition, before making MEM analysis, in order to improve signal to noise ratio S / N and signal / reverberation ratio S / R, a space prefilter was newly designed to limit the bandwidth of the spatial frequency. Research shows that, even if the S / N is 0dB, but also get better azimuth resolution.