Characterizing noise in the global nuclear weapon monitoring system

Feb 11, 2013

Under the auspices of the Comprehensive Nuclear-Test-Ban Treaty Organization, a worldwide monitoring system designed to detect the illegal testing of nuclear weaponry has been under construction since 1999. The International Monitoring System is composed of a range of sensors, including detectors for hydroacoustic and seismic signals, and when completed, will include 60 infrasound measurement arrays set to detect low-frequency sound waves produced by an atmospheric nuclear detonation.

The monitoring system's effectiveness, however, is limited because of noise from infrasound signals produced by natural sources, such as wind, surf, and thunder, and by anthropogenic activity, such as mining, industrial operations, and flying aircraft. To improve the identification of atmospheric detonations (or any other signal of interest for the global infrasound network), Matoza et al. have devised a method to eliminate irrelevant sensor noise. Unlike previous research, which treated all noise affecting the infrasound sensors equally, they split the noise into two categories: coherent noise, produced by consistent infrasound sources but that is unrelated to the signals of interest, and incoherent noise, infrasound produced by random sources such as wind.

Analyzing the observations of 39 infrasound stations from April 2005 to December 2010, the authors identify consistent sources of coherent noise, including ocean microbaroms, , the sounds of the surf and thunder, and human activity. Identifying the frequencies associated with different sources could improve signal processing, which would in turn improve an infrasound array's ability to isolate the signals it is designed to monitor.

Explore further: Soil nutrients may limit ability of plants to slow climate change

More information: Coherent ambient infrasound recorded by the International Monitoring System, Geophysical Research Letters, doi: 10.1029/2012GL054329 , 2013 http://onlinelibrary.wiley.com/doi/10.1029/2012GL054329/abstract

Related Stories

Tropical cyclone waves detected with infrasound sensor array

Jan 15, 2013

The strong winds of a tropical cyclone whip up the sea surface, driving ocean waves a dozen meters (about 40 feet) high. When one such ocean wave runs into another wave that has an equal period but is traveling in the opposite ...

The inaudible symphony analyzed

Nov 03, 2008

By measuring 'inaudible' sounds, events like illegal nuclear tests can be detected. This 'infrasound' can also help us understand more about the upper atmosphere, according to Läslo Evers. Evers will receive a PhD based ...

Recommended for you

Ocean currents impact methane consumption

15 hours ago

Large amounts of methane - whether as free gas or as solid gas hydrates - can be found in the sea floor along the ocean shores. When the hydrates dissolve or when the gas finds pathways in the sea floor to ...

Study shines new light on the source of diamonds

20 hours ago

A team of specialists from four Australian universities, including the University of Western Australia, has established the exact source of a diamond-bearing rock for the first time.

Source of Earth's ringing? French team views ocean waves

20 hours ago

Three researchers in France have authored "How ocean waves rock the Earth: Two mechanisms explain microseisms with periods 3 to 300 s," published in Geophysical Research Letters, a journal of the Americ ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.