Subscribe free to our newsletters via your
. 24/7 Space News .




NUKEWARS
GPS Stations Can Detect Clandestine Nuclear Tests
by Staff Writers
Viennna, Austria (SPX) Jun 09, 2011


illustration only

At the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) meeting this week, American researchers are unveiling a new tool for detecting illegal nuclear explosions: the Earth's global positioning system (GPS).

Even underground nuclear tests leave their mark on the part of the upper atmosphere known as the ionosphere, the researchers discovered, when they examined GPS data recorded the same day as a North Korean nuclear test in 2009. Within minutes on that day, GPS stations in nearby countries registered a change in ionospheric electron density, as a bubble of disturbed particles spread out from the test site and across the planet.

"Its as if the shockwave from the underground explosion caused the earth to 'punch up' into the atmosphere, creating another shockwave that pushed the air away from ground zero," said Ralph von Frese, professor of earth sciences at Ohio State University and senior author on the study.

Jihye Park, a doctoral student in geodetic science at the university, is presenting the results of the study this Wednesday, Thursday, and Friday in a poster session at the CTBTO meeting in Vienna, Austria.

International authorities already possess several methods for detecting illegal nuclear tests, Park said. Seismic detectors pick up shockwaves through land, and acoustic sensors monitor for shockwaves through water and the air for tests that happen above ground. Chemical sensors detect airborne radioactive gas and dust as definitive evidence of a nuclear explosion. However, these particles may be lacking if the explosion is contained deeply below ground.

"GPS is a complement to these other methods, and can help confirm that a nuclear test has taken place - especially when the test was underground, so that its effect in the air is very subtle, and otherwise nearly impossible to detect," she said.

While GPS was designed for location purposes, the technology has always been especially sensitive to atmospheric disturbances, said Dorota Grejner-Brzezinska, a professor of geodetic science at Ohio State and Park's advisor.

"GPS signals must pass from transmitters on satellites high above the planet down to ground-based receivers," Grejner-Brzezinska explained. "Air molecules - more specifically, the electrons and other charged particles in the ionosphere - interfere with the signal, generating position error. Part of our research concerns how to compensate for that vulnerability and make GPS work better. Jihye found a way to take that vulnerability and turn it into something useful."

Park wrote computer algorithms that search GPS signals for patterns indicating a sudden fluctuation in atmospheric electron density in specific locations, which is what happens when a shockwave pushes a bubble of air through the atmosphere. As the GPS signal passes through the edge of the bubble, the change in electron density disturbs the signal in a noticeable way.

Park was able to utilize data collected from GPS receivers that the International GNSS Service (IGS) has planted around the globe for research purposes. Five of the IGS receivers scattered in Eastern Asia provided data for this study, as did six receivers belonging to the South Korean GPS network.

When Park analyzed the data from the 11 GPS stations, she detected a sudden spike in atmospheric electron density after the May 25, 2009 underground test, which is believed to have happened just before 1:00 a.m. Coordinated Universal Time that day.

Within 25 minutes, the shockwave had traveled 225 miles to the nearest GPS station in the study, which was located in Inje County, in Gangwon Province, South Korea. That means that it was traveling through the air at 9 miles per minute, or 540 miles per hour. Within that first hour, it had reached all 11 stations.

Based on the timing of the shockwave, the researchers traced the origin of the explosion back to P'unggye, in Hamyong Province, North Korea. This finding agrees with seismic data from the event, which was collected by the CTBTO and the US Geological Survey.

The researchers will continue this work as Park earns her PhD, and they are seeking funding and partnerships to expand it further. In the meantime, they have submitted a paper on the discovery to the journal Geophysical Research Letters.

Collaborators on the study include Yu Morton, professor of electrical and computer engineering at Miami University in Oxford, Ohio, and Luis Gaya-Pique of CTBTO's On-Site Inspection Division.

.


Related Links
-
Learn about nuclear weapons doctrine and defense at SpaceWar.com
Learn about missile defense at SpaceWar.com
All about missiles at SpaceWar.com
Learn about the Superpowers of the 21st Century at SpaceWar.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








NUKEWARS
West presses ahead with Syria resolution at IAEA meet
Vienna (AFP) June 8, 2011
The United States and its western allies pressed ahead with a resolution against Syria at a meeting of the UN atomic watchdog here Wednesday, despite opposition from Russia and China. A draft of the resolution obtained by AFP found Syria in "non-compliance with its obligations" towards its nuclear safeguards agreement with the International Atomic Energy Agency. And in view of that non-c ... read more


NUKEWARS
The Power of A Moon Rock

Looking at the volatile side of the Moon

Parts of moon interior as wet as Earth's upper mantle

NASA-Funded Scientists Make Watershed Lunar Discovery

NUKEWARS
New solar system formation models indicate that Jupiter's foray robbed Mars of mass

Opportunity Studies Rock Outcrop

A Salute to the Spirit of Mars

One year in isolation

NUKEWARS
NASA Spending Shift to Benefit Centers Focused on Science and Technology

Japan's next gizmo: brainwave-controlled cat ears

FOGE Reaches 10

Testing Spacesuits in Antarctica - part 3

NUKEWARS
Building harmonious outer space to achieve inclusive development

China's Fengyun-3B satellite goes into official operation

Venezuela, China to launch satellite next year

Top Chinese scientists honored with naming of minor planets

NUKEWARS
Soyuz heads to ISS carrying Russian, US, Japanese astronauts

Soyuz heads to ISS carrying Russian, US, Japanese astronauts

New Crew Members Prepare for Launch

ATV-2 adjusts ISS orbit; ext TMA Soyuz assembled

NUKEWARS
Shipments Of Sea Launch Zenit-3Sl Hardware Resume On Schedule

US Army supports student launch program

Boeing Opens Exploration Launch Systems Office in Florida

Payload processing underway for ASTRA 1N

NUKEWARS
Rage Against the Dying of the Light

Second Rocky World Makes Kepler-10 a Multi-Planet System

Kepler's Astounding Haul of Multiple-Planet Systems Just Keeps Growing

Bennett team discovers new class of extrasolar planets

NUKEWARS
Chinalco sets up rare earths processing firm

Apple takes a giant leap into the 'iCloud' cloud

Phase Change Memory-Based Moneta System Points to the Future of Computer Storage

Thomas Edison also invented the concrete house




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement