Citation

Rinehart HS, Clark C, Gray M, Dillion K. J. Acoust. Soc. Am. 2012; 132(3): 2074.

Affiliation

Miltec Systems, Ducommun Miltec, 678 Discovery Dr NW, Huntsville, AL 35806hrinehart@one.ducommun.com.

Copyright

(Copyright © 2012, American Institute of Physics)

DOI

10.1121/1.4755647

PMID

22979729

Abstract

April 25-28, 2011 has been identified by many as the most significant and severe single-system outbreak of tornadoes in recorded history. One day in particular, the 27th of April, has been classified by the National Oceanic and Atmospheric Administration (NOAA) as the fourth deadliest tornado outbreak in US history. Severe tornadic activity on this day levied catastrophic damage to life and property across areas of Mississippi, Alabama, Georgia and Tennessee. During this outbreak, multiple Ducommun Miltec-developed infrasound sensors collecting continuous, high resolution data were deployed in two-dimensional array configurations in Northern Alabama. Prior research on the collection and analysis of infrasonic emissions from severe weather phenomenon has provided much insight on the nature of tornado-generated infrasound. Our effort focuses on the application of novel bearing estimation algorithms using closely spaced (4-6 m) array elements. Direction of Arrival (DOA) estimates, derived from Blind Source Separation (BSS) techniques, will be presented for at least two significant tornadoes: the long-track EF5 that impacted Hackleburg and Phil Campbell, AL and the large multi-vortex EF4 that struck Cullman, AL. Correlation of infrasound detection and bearing estimate initiation and termination with NOAA Storm Prediction Center (SPC) Storm Reports will also be reviewed.

Language: en