A Bird's-Eye View on Ambient Infrasonic soundscapes
A Bird's-Eye View on Ambient Infrasonic soundscapes
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DOI：
10.1029/2021gl094555
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发表时间：
2021-09-16
影响因子：
5.2
通讯作者：
Evers, Laslo G.
中科院分区：
文献类型：
--
作者：
den Ouden, Olivier F. C.;Smets, Pieter S. M.;Evers, Laslo G.
介绍了一种以绝对值重建微气压声景的方法。的音景进行比较，远程次声记录从次声阵列I23 FR（Kerguelen岛）和现场录音的INFRA-ESTA，克罗泽群岛附近部署的生物记录。重建方法考虑了所有的声学贡献，分为渐逝微气压（直接在源上方检测）和传播微气压（在长距离检测）。它是通过对海洋表面上的声强进行积分来计算的，与量化传播损失和传播时间的传递函数进行卷积。在0.1-0.3 Hz的微气压波段中，85%的测量结果的重建音景在2.7 dB以内。次声音景对于了解环境次声噪声场至关重要，也是大气遥感、自然灾害监测和全面禁止核试验条约核查等应用的基本需求。简明扼要微气压是低频、不可闻声音（即次声）的无所不在的声源。它们在次声频谱内具有特征和连续的特征，通常被归类为环境噪声。微气压信号可以分为直接信号和传播信号，前者只能在源附近检测到，后者传播距离很远。在嘈杂的条件下，微气压可以掩盖感兴趣的次声信号，如火山或爆炸的次声。对环境噪音领域的深入了解可改善自然灾害监测和《全面禁止核试验条约》的核查。本文介绍了一种微气压源场的重建方法。该方法以绝对数量重建全向音景。这是对以前的方法的显著改进，以前的方法只考虑了归一化的最响的源区域。重建的音景与微气压记录的微气压计阵列和红外线，一个微型传感器部署在克罗泽群岛附近的生物记录。比较显示，85%的时间之间的建模和观察到的音景的统计协议。
A method is introduced to reconstruct microbarom soundscapes in absolute values. The soundscapes are compared to remote infrasound recordings from infrasound array I23FR (Kerguelen Island) and in situ recordings by the INFRA-EAR, a biologger deployed near the Crozet Islands. The reconstruction method accounts for all-acoustic contributions, divided into evanescent microbaroms (detectable directly above the source) and propagating microbaroms (detectable over long ranges). It is computed by integrating acoustic intensities over the ocean surface, convolved with the transfer function quantifying the propagation losses and propagation time. The reconstructed soundscapes are found within 2.7 dB for 85% of the measurements in the microbarom band of 0.1-0.3 Hz. Infrasonic soundscapes are essential for understanding the ambient infrasonic noise field and are a basic need for applications, such as atmospheric remote sensing, natural hazard monitoring, and verification of the Comprehensive Nuclear-Test-Ban Treaty.Plain Language Summary Microbaroms are omnipresent sources of low-frequency, inaudible sound, that is, infrasound. They have a characteristic and continuous signature within the infrasound spectrum and are often classified as ambient noise. The microbarom signals can be divided into a direct signal, only detectable close by the source, and a propagating signal, which travels over large distances. Under noisy conditions, microbaroms can mask infrasonic signals of interest, such as infrasound from volcanoes or explosions. Insights in the ambient noise field improve natural hazards monitoring and the verification of the Comprehensive Nuclear-Test-Ban Treaty. In this study, a method for the reconstruction of the microbarom source field is introduced. The method reconstructs omnidirectional soundscapes in absolute numbers. This is a significant improvement to previous approaches, which accounted for the normalized loudest source region only. The reconstructed soundscapes are compared with microbarom recordings by microbarometer arrays and the INFRA-EAR, a miniature sensor deployed as a biologger near the Crozet Islands. The comparison shows a statistical agreement for 85% of the time between the modeled and observed soundscapes.