Development of a Compact Wind and Water Mitigation System for Deployment of Infrasound Sensors on Unmanned Surface Vehicles
Technical Report,01 Sep 2017,01 Sep 2018
Naval Information Warfare Center Pacific San Diego United States
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This report was completed for the Maritime Infrasound Monitoring MIM project. One objective of the MIM project at the time testing was done for this report was to develop a unique windscreen design for deployment with an infrasound sensor aboard a small, unmanned surface vehicle USV. The unique windscreen must possess several specific capabilitiesfeatures it must 1 reduce wind noise, 2 provide protection from water, and 3 be suitably compact for deployment on a Liquid Robotics SV23 USV. This report documents the results of a test performed to evaluate potential windscreen designs that address these requirements. A side-by-side test event was performed at NASA Langley in Hampton, VA from April 1320, 2018 to investigate the performance of various infrasound sensors and windscreens. The premise for the test was primarily to investigate the performance of the closed-cell foam windscreens being developed by NASA in terms of transmissivity and wind noise reduction. Additionally, as part of this research, other compact windscreens were evaluated to provide comparison points. These alternative windscreens consisted of two perforated metal windscreens tent and cylinder from Army Research Lab, a trampoline fabric tent windscreen from Hyperion Technology Group, and a perforated metal colander provided by SSC Pacific. In addition to the windscreens, two different infrasound sensors were evaluated an electret microphone being produced for NASA by PCB Piezotronics, and a piezoelectric microbarometer produced by Hyperion. The results of our testing show that the closed-cell foam windscreens do not attenuate the infrasound signal, provided a properly designed back chamber is used improper venting results in signal attenuation. Both versions of the closed-cell foam windscreens those designed for use with NASA microphone and Hyperion microbarometer demonstrated good wind mitigation performance.
- Electrical and Electronic Equipment