The Citizen Array Network

Empowering a new generation of nuclear detectives

http://citizenarray.net

@citizenarray

Devabhaktuni Srikrishna, Mike McNerney, Bill Coleman

Technology for Global Security (Tech4GS), Silicon Valley, USA

Acknowledgements: Jay Zucca, Lawrence Livermore National Laboratory (LLNL-PMS-671959)

Learning curve is steep… this book can help

This book spells it out.

Read it and write a review on Amazon!

Today: CTBTO Monitoring Network

321 stations worldwide

Four Types of Stations

  • ground (seismic)
  • sea (hydroacoustic)
  • air (infrasound)
  • atmospheric (radionuclide)

Cost: ~$1+ billion

Cost per station: ~$1+ million each

Annual Budget: ~$45 million

Data: aggregated by CTBTO available to member states

What if a seismic station could fit in a backyard?

7 billion people across the world with a vested interest in nuclear security

Example: Ham Radio

3 million ham radio operators worldwide

“Amateur Radio operators come from all walks of life -- doctors, students, kids, politicians, truck drivers, movie stars, missionaries and even your average neighbor next door.” -- American Radio Relay League

Tomorrow: Citizen Array Network

?

1+ million stations worldwide

Start with one type, expand later

  • ground (seismic)
  • sea (hydroacoustic)
  • air (infrasound)
  • atmospheric (radionuclide)

Cost: paid for by nuclear security enthusiasts


Cost per station: < $1000 (long-term target)

Data: available to public

Could it improve the state of the art in forensic seismology?

Network Performance of the CTBTO Monitoring Regime

CTBTO S&T 2011

321 stations worldwide

Four Types of Stations

  • ground (seismic)
  • sea (hydroacoustic)
  • air (infrasound)
  • atmospheric (radionuclide)

Cost: ~$1+ billion

Cost per station: ~$1+ million each

Annual Budget: ~$45 million

Data: aggregated by CTBTO available to member states

Richard Garwin on “Decoupling”

CTBTO S&T 2011

“A very powerful method has been proposed by Albert Latter ... His method consists of making an enormous underground cavity and setting off the atomic bomb in the middle of the cavity. One can calculate that the apparent size of the explosion is thereby reduced by a factor about 300. (Now better estimated as a factor of about 70).... It is generally accepted that the radius of the cavity for full decoupling in either salt or rock is 25 meters for a 1-kt explosive, with the volume of the required air- filled cavity increasing linearly with the yield to be decoupled. ” [Garwin]

So then what if someone tried the following...

  • A decoupled nuclear test (to evade seismic monitoring)
  • Near a medical isotope factory (to evade radionuclide detection)
  • Underneath a forested, mountainous area (to evade subsidence detection by satellite)

???

US National Academy of Sciences on “Decoupling” (2012)

“Table 4-2 summarizes the capability of the IMS seismic detection component and open regional systems to detect and locate underground explosions at two probability of detection levels, 10 percent and 90 percent, and in various regions of the world.

The technical developments that could support this potential improvement include some combination of the use of array processing… waveform correlation methods; or other signal processing enhancements that might lead to further improvement in detection threshold, perhaps combined with the use of additional stations.” [NAS]

What’s needed: more stations in more locations

Regional arrays:

~1,000 km detection distance

e.g. ARCES (Norway)

“Regional waves enhance the ability to detect cavity decoupling because higher frequency waves are more observable at regional distances and decoupling is smaller at higher frequencies (12 at 10 Hz), compared to teleseismic waves (70 at 1 Hz).” [Hafemeister]

What’s needed: more stations in more locations

Teleseismic arrays:

~10,000 km detection distance

e.g. Yellowknife Array (Canada)

“Potential test sites are still likely to be in network 'holes' (e.g. North Korea; remote military ranges, non-instrumented oceanic islands etc). So detection of remote signals would still be important.” [Pearce]

CTBTO Gold Standard: Seismic at bedrock

CTBTO Tutorial: “A seismometer needs to be connected to solid rock to detect seismic waves”

Today: CTBTO Monitoring Network

CTBTO seismic networks are high-quality, extremely low-noise systems that are expensive to install and operate -- impractical to deploy large numbers. However, if large numbers of such systems were deployed, array calculations could be done dynamically and reduction of noise could be achieved.

Such a system would also need to be sensitive to local and regional seismic events defined as up to about 2000 km from the source, in addition to teleseismic events (10,000 km away). The system would need to be sensitive to seismic energy in the 0.05 to 10 hertz band.

321 stations worldwide

Four Types of Stations

  • ground (seismic)
  • sea (hydroacoustic)
  • air (infrasound)
  • atmospheric (radionuclide)

Cost: ~$1+ billion

Cost per station: ~$1+ million each

Annual Budget: ~$45 million

Data: aggregated by CTBTO available to member states

Seismic detection using iPhone

Drell & Stubbs, How to Detect a Nuclear Test on Your iPhone, Foreign Policy, April 2013

e.g. Stanford Quake Catcher Network uses desktop and mobile devices

Is there an intermediate between iPhone and bedrock?

200 Hz

2 bytes per sample

3 channels -- x,y,z

low data requirements

e.g. Guralp Systems CMG-EDU-V

30 seconds to 50 Hz

Lightweight, waterproof and self-contained

Quick and easy installation

[Guralp]

“Among the main sensor manufacturers both Nanometrics and Guralp (under testing) currently have sensor-digitizer integrated solutions with lower performance (but still reasonable) and lower price than IMS sensors (~1500 $). Mass-production could obviously have an impact on the price.” [Grenard]

Tomorrow: Citizen Array Network

?

1+ million stations worldwide

Start with one type, expand later

  • ground (seismic)
  • sea (hydroacoustic)
  • air (infrasound)
  • atmospheric (radionuclide)

Cost: paid for by nuclear security enthusiasts


Cost per station: < $1000 (long-term target, not at first)

Data: available to public

Imagine if it were on Amazon.com...

Home Broadband Seismometer

by Citizen Array Network

Stunning sensitivity and dynamic range

60 Second Setup and easy installation

Wi-Fi, live stream from your basement or backya to the cloud in under a minute

Incredible range of frequencies: 30 seconds to 50 Hz

Monitor seismic activity at home while you are away

Make the world a safer place.

Contribute to enhancing global nuclear security

In 2014, at most several thousand of these type of units were produced worldwide (estimated by Guralp systems)

A consumerized version of broadband seismometers has potential to expand production into tens of thousands, if not hundreds of thousands bringing down the production cost.

Technical Challenge = Signal versus Noise

Seismic, Wind, Trees

“Cultural”

Noise from the Device itself

Dealing with noise

Uncorrelated Noise Reduction

(“Square Root N” gain -- see [Douglas])

  • # of Array Elements (processing)
  • # of Arrays (reduced variance in estimates of location, time, direction, magnitude, etc)

Correlated noise cancellation?

measure
“cultural” noise

cancel
“cultural” noise

Some other possibilities for locating Citizen Stations: homes on mountains, oil wells, irrigation pumps...

Citizen Array Network:

Compute Infrastructure Needed

Citizen Arrays

Internet

Processing + Storage

This information would then be available (along with IMS data and IDC products provided by the CTBTO) to decision makers.

Why build the Citizen Array Network?

  • Unique way for citizens around the world to contribute to nuclear security.
    • Offer everyone a role in fulfilling the mission of global nuclear security

  • Improve knowledge of seismic wave propagation between different points of the earth.
    • “Seismic waves travel at different speeds through different rock types. If this is not fully accounted for in the Earth models used for seismic location, the event area will not be centered on the true location. These calibrations have been done using well-located reference events to derive travel time corrections for all future nearby events.” [NAS]

  • Contribute new seismic stations to the global test detection network.
    • “Detection and identification sensitivities are governed by having an adequate number of sensors to record the higher frequency regional signals.” [NAS]

Next Step: Answer Open Questions

How should a citizen array network be designed? (technology)

What hardware is useful for each station?

What is the software architecture?

How much are citizens willing to pay for each station? (price-elasticity)

How much will each citizen station cost? (tradeoffs)

How does cost depend on capability?

What are other applications of citizen array networks?

  • earthquakes, integration with early warning systems
  • volcanos
  • nuclear accidents

….

price-sensitivity, consumerization, when you do a poll with a Likert scale you will find some will be very disinterested, disinterested, neither interested or disinterested, interested, very interested. There will be some price sensitivity for this as well. So the true market for this is not yet known, but there is a good reason to believe it is much larger than most people may expect.

What do we need at this stage?

Volunteers to ask and answer research questions, define the system tradeoffs of the Citizen Array Network.

Output: an architecture paper on Citizen Array Networks.

Based on that we can begin development, fundraising, deployment, and global scaling.

Help launch the world’s first nuclear detection network by citizens

Join the discussion

  • Web: http://www.citizenarray.net (link to this presentation)
  • Twitter: @citizenarray
  • Email: citizenarray@googlegroups.com (discussion mailing list)
  • Discuss: https://citizenarray.slack.com/ (system/architecture discussions)

Send us an email to join the mailing list or Slack group (sri@tech4gs.org)

References

[Douglas] Forensic Seismology and Nuclear Test Bans (link)

[Pearce] Citizen Science for nuclear test detection (link)

[Grenard] Citizen Science - infrasound (link)

[Carter] Network Performance of the CTBT Monitoring Regime (link)

[Schweitzer] Seismic Arrays (link)

[Yellowknife] The Yellowknife Seismological Array (link)

[Garwin] The Scientific Roots and Prospects for the CTBTO and the IMS (link)

[NAS] The Comprehensive Nuclear Test Ban Treaty: Technical Issues for the United States (2012) (link)

[Guralp] Guralp CMG-EDU-V Single-component seismometer (link)

[Hafemeister] Progress in CTBT Monitoring Since its 1999 Senate Defeat (link)

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@tech4gs

The Citizen Array Network - Google Slides