A post-processing technique to estimate the signal-to-noise ratio and remove echosounder background noise
A post-processing technique to estimate the signal-to-noise ratio and remove echosounder background noise
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DOI：
10.1093/icesjms/fsm112
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发表时间：
2007-09-01
影响因子：
3.3
通讯作者：
Higginbottom, Ian
中科院分区：
文献类型：
--
作者：
De Robertis, Alex;Higginbottom, Ian
提出了一种简单有效的后处理技术，用于估计有源ping过程中的回波背景噪声电平和信噪比。与主动ping期间的其他噪声估计方法类似，该方法假设采样声信号的某些部分由背景噪声主导，而反向散射发射信号的贡献可以忽略不计。如果满足这一假设，该方法将提供与发射器被禁用时接收器测量的背景噪声相当的鲁棒和准确的估计。它在短时间间隔内提供重复的噪声估计，而无需用户干预，这在背景噪声随时间变化的情况下是有益的。在背景噪声在记录信号的一部分中占主导地位的情况下，对噪声的影响进行一阶校正并估计信噪比来评估背景噪声对声学测量的影响是很简单的。噪声校正和基于信噪比的阈值有可能改善在低信噪比情况下声学测量的推断，例如在嘈杂的船只上进行测量时，使用多频率技术进行测量，在较远的范围内进行测量，以及在声学目标较弱的情况下进行测量，例如无脊椎动物和没有鳔的鱼类。
A simple and effective post-processing technique to estimate echosounder background-noise levels and signal-to-noise ratios (SNRs) during active pinging is developed. Similar to other methods of noise estimation during active pinging, this method assumes that some portion of the sampled acoustic signal is dominated by background noise, with a negligible contribution from the backscattered transmit signal. If this assumption is met, the method will provide robust and accurate estimates of background noise equivalent to that measured by the receiver if the transmitter were disabled. It provides repeated noise estimates over short intervals of time without user intervention, which is beneficial in cases where background noise changes over time. In situations where background noise is dominant in a portion of the recorded signal, it is straightforward to make first-order corrections for the effects of noise and to estimate the SNR to evaluate the effects of background noise on acoustic measurements. Noise correction and signal-to-noise-based thresholds have the potential to improve inferences from acoustic measurements in lower signal-to-noise situations, such as when surveying from noisy vessels, using multifrequency techniques, surveying at longer ranges, and when working with weak acoustic targets such as invertebrates and fish lacking swimbladders.