Comparison and Validation of Acoustic Response Models for Wind Noise Reduction Pipe Arrays

Abstract

The detection capability of the infrasound component of the International Monitoring System (IMS) is tightly linked to the performance of its wind noise reduction systems. The wind noise reduction solution implemented at all IMS infrasound measurement systems consists of a spatial distribution of air inlets connected to the infrasound sensor through a network of pipes. This system, usually referred to as “pipe array,” has proven its efficiency in operational conditions. The objective of this paper is to present the results of the comparison and validation of three distinct acoustic response models for pipe arrays. The characteristics of the models and the results obtained for a defined set of pipe array configurations are described. A field experiment using a newly developed infrasound generator, dedicated to the validation of these models, is then presented. The comparison between the modeled and empirical acoustic responses shows that two of the three models can be confidently used to estimate pipe array acoustic responses. This study paves the way to the deconvolution of IMS infrasound data from pipe array responses and to the optimization of pipe array design to IMS applications.

Natural and Anthropogenic Sources of Seismic, Hydroacoustic, and Infrasonic Waves: Waveforms and Spectral Characteristics (and Their Applicability for Sensor Calibration)

“…One way to identify suitable periods is described in Green et al ( 2021 ). Marty et al ( 2017 ) use a controlled source (infrasound generator) in addition to background pressure fluctuations for calibration. The microbarom peak is also suitable for calibration of infrasound sensors, according to Bowman and Lees ( 2017 ).…”

“…Le Pichon et al 2009 ). The noise field in general is created by a superposition of pressure fluctuations from various local, regional and global sources such as microbaroms, wind, traffic, or industry (Christie and Kennet 2007 ; Marty et al 2017 ). Ambient noise covers the entire frequency range between 0.03 and 10 Hz (Bowman et al 2005a ), with individual sources found in certain narrower frequency bands.…”

“…Wind is generally considered the most important source of noise, generating pressure fluctuations by hydrostatic and dynamic effects (wind turbulence) in the atmospheric boundary layer (Christie and Kennet 2007 ; Le Pichon et al 2009 ; Marty et al 2017 ) and is responsible for the majority of pressure fluctuations in the frequency range between 0.01 and 5 Hz (Matoza et al 2013 ). Wind also generates measurable noise in the range between 0.003 and 0.01 Hz (Alcoverro and Le Pichon 2005 ).…”