Developments in infrasound sensors and wind noise reduction

Abstract

As applications of infrasound grow so does the need for reasonably priced microphones and attendant wind noise reduction approaches. Many applications require sensor systems with frequency response between 0.01 and 10 Hz and a dynamic range between a few micropascals and ten Pascals and operate under severe environmental conditions. Sensor systems are often in remote areas with only occasional maintenance visits. Current installations usually employ classic condenser microphones or sliding wire microbarographs along with porous hose wind filters. Next generation sensors use optical fiber sensors long enough to average out wind noise or multiple sensors which allow for electronically canceling wind noise. Some of the advantages and characteristics of these sensors will be described. Calibration of sensors over the range of conditions remains a challenge. Progress on calibration facilities will be included in the discussion. [Work supported by the US Army Space and Missile Defense Command.]