Development of a Compact Wind and Water Mitigation System for Deployment of Infrasound Sensors on Unmanned Surface Vehicles

Abstract

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 capabilities/features: it must (1) reduce wind noise, (2) provide protection from water, and (3) be suitably compact for deployment on a Liquid Robotics SV2/3 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.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2019
Accession Number
AD1084530

Entities

People

  • Doug Grimmett
  • Randall Plate

Organizations

  • Naval Information Warfare Center Pacific

Tags

Communities of Interest

  • Autonomy
  • Sensors

DTIC Thesaurus Topics

  • Background Noise
  • Data Acquisition
  • Deployment
  • Electrets
  • Engineering
  • Frequency
  • Frequency Bands
  • Frequency Response
  • Information Warfare
  • Materials
  • Military Research
  • Noise
  • Noise Reduction
  • United States Government
  • Unmanned Surface Vehicles
  • Vehicles
  • Warfare

Readers

  • Acoustics.
  • Materials Science
  • Unmanned Aerial System (UAS) Autonomous Capabilities and Mission Reconnaissance.

Technology Areas

  • AI & ML
  • Autonomy