LFM信号限幅失真对侧扫声纳声图的影响

本文分情况讨论了LFM信号限幅失真对脉冲压缩及侧扫声图的影响并进行了湖试验证。结果表明:限幅失真对于脉压波形的主瓣几乎没有影响,即不会影响到声图的分辨率,但是会使脉压波形的幅度产生失真。当限幅程度较大时,由于信号的叠加会进一步恶化脉压波形,使脉压信号的幅度明显降低,甚至产生假目标,信号的动态变化范围被严重压缩;即使当单个信号不限幅时,而由于多目标回波相互叠加也可能会引起信号限幅,此时也可能对处理结果造成较为严重的失真,使信号动态范围被压缩。

Effect of Clipping Distortion of LFM signals on Side-Scan Sonar Imaging

This article discusses the clipping distortion of LFM signals in different conditions on the pulse compression and side-scan sonar imaging.The results showed that:clipping distortion has little effect on the width of the main lobe,in other words,it will not affect the resolution of the sonar imaging,but there will be distortion of the amplitude of pulse pressure.When the clipping distortion is large,the wave of pulse compression will be worse with the superposition of signals.The amplitude of the pulse will be significantly reduced.What was worst,there will be false targets and the dynamic range of the pulse will be seriously compressed.Even if a single signal did not reach the limiting threshold,as the superposition of multi_target echo signals may cause the signals be clipped.Then there may be serious distortion and the signal dynamic range will be compressed.