Communications Enabling the NextGeneration of Seismic Systems

Frank Vernon2012 IRIS Workshop

OverviewCurrent use of communications in

seismology

Technical requirements

Terrestrial communications

Marine communications

Summary

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WANT

UOSS

COR

TARA

CMBPASC

PFO TUC

RSSD

FFC

COLA

KDAK

ANMO

HKT

CCM

TEIGSJG

DWPFBBSR

WCI

WVT

SSPA

KIP

POHAJOHN

XMAS

RARPTCN RPN

MSEY

DGAR

PALK

CHTOTATO

MIDWMAJO

PET

BILLTIXI

YAK MA2

TLY

ULN

LSA

HIA

BJT

XAN SSE

MDJ

KMI

INCN

YSSERM

ENH

COCO

SBA

CTAORAO

HNR

BTDF

KAPI

MSVF

GUMO

WAKE

KWAJ

FUNA

AFI

DAV

QSPA

CASY

SUR

LBTB

LSZ

MSKU

FURI

MBAR

KMBO

NWAOTAU

WRAB

SNZO

EFI

PMSA

HOPE

ASCN

SHEL

TRQALCO

NNA

PAYG

OTAVPTGA

JTSSDV

LVC

SAML

SACV

CMLAHRV PAB

SFJD BORG

ESK

TRIS

RCBR

TSUM

KOWA

ALEKBS

NRIL

ARU

BRVK

KURKMAKZ

WMQNIL

RAYN

ABKT

LVZ

OBN

KEV

KONO

KIEVBFO

GRFO

GNIANTO

AAK

PMG

KIV

QIZ

MBWA

ILAR

PDARNVAR

ADK

ATTU

VNDA

s

TXAR

SDDRBCIPTGUH BBGH

GRGR

ANWB

GTBY

ABPO

MCQ

KBL

GRTKMDTJSLBS

MACI

KNTN

HKPS

IRIS / IDA Stations IRIS / USGS Stations Affiliate Stations Planned Stations

2/2012

GLOBAL SEISMOGRAPHIC NETWORK

Global Seismic NetworkTelemetry

Essentially all stations have real timetelemetryData used for real time processing by

multiple usersRapid earthquake notificationSource parameter estimation (location,

magnitudes, ...)Tsunami warning

Telemetry to nearest Internet POPSatelliteDirect link

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Regional Networks -Alaska

National and Regional SeismicNetworks Telemetry

Essentially all stations have real timetelemetryData used for real time processing

Rapid earthquake notificationSource parameter estimation (location,

magnitudes, ...)Tsunami warning

Telemetry to nearest Internet POPDedicated networks Satellite Mobile phone

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PASSCAL Ad Hoc Telemetry

PASSCAL AdHoc Telemetry

USArray Transportable Array

Station Photos

C35A Minnesota

142A Louisiana

958A Florida

E27A North Dakota

Modularity in Communications

96% Cellular3% VSAT

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Cellular Modem

AC VSAT

Solar VSAT

Telemetry FeasibilitySites are selected with the telemetry option as part of the plan.

The available options in order of preference are;

Verizon digital service (EVDO)AT&T (GPRS / GSM)

Radio to a VSAT located near AC PowerRadio to a location with AC power that has DSL or Cable

Modem service available, not landowners.Radio to a VSAT powered by solar panels.Radio range is 20 km line of sight. It is most often a few hundred meters.

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VSAT

Works in remote locations

Slow connections

Longer to install

During Recon:

Check for 35 degree elevationangle, south-southwest

Locate near a power source (AC Plug)

Radio line of sight to seismicvault

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Current telemetry

Network StationSpacing

Bandwidth # stas StationPower

GSN ~2000 km ~5 kbit/s ~150 100+ w

Reg/Nat 20 - 500 km ~20 kbit/s 20 - 300 5 - 100+ w

TA 70 km ~5 kbit/s 450+ 6 w

PASSCAL 0.02-100 km 0 - 30 kbit/s 10 - 1000 2 - 6 w

Current telemetry

Network StationSpacing

Bandwidth # stas StationPower

GSN ~2000 km ~5 kbit/s ~150 100+ w

Reg/Nat 20 - 500 km ~20 kbit/s 20 - 300 5 - 100+ w

TA 70 km ~5 kbit/s 450+ 6 w

PASSCAL 0.02-100 km 0 - 30 kbit/s 10 - 1000 2 - 6 w

Terrestrial Telemetry options

Comm Type Power Distance BW bytes/Joule

Wireless mobile 2 w ~20 km 300 kbs 19 kB/j

Wireless Freewave 3 w 100+ km 154 kbs 6.4 kB/j

Wireless Afar 5 w 50 km 2750 kbs 68 kB/j

Satellite Wild Blue 30 w 1000+ km 50 kbs 0.2 kB/j

Satellite Began 4 w 1000+ km 250 kbs 7.8 kB/j

Satellite Iridium 5 w 1000+ km 2.4 kbs 0.06 kB/j

Current Realtime Data at DMC

Current Realtime Data at DMC

Goals

Transition to telemetry based systemsNear real time access to dataBetter QCBetter data returnAccess to data from remote sitesConnection to nearest Internet Point of Presence (POP)

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Current BarriersPower for PASSCAL type experiments2-30 W for commsBandwidth in remote areasIRIDIUM Installation Additional equipment (antennas, cables, telemetry, time)Line-of-sight to nearest neighbor or Internet POPterrain and vegetationSoftware configurationautomated initiation of dataflow (currently done on TA)Transformation to streaming processing model from batch

offline processing model

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OpportunitiesRadio and Satellite technologies are mature

Improvements being made

power management

efficient use of bandwidth

duty cycling

Communications for interstation spacings > 10 km

mobile

ad hoc networking

satellite

controlled by physics - line of sight, power

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Present Mobile Coverage

Present Mobile Coverage

OpportunitiesCommunications for interstation spacings < 1 km

dedicated mesh networks

exemplar company - wireless SEISMIC

max 15000 channels

up to 21 days of battery

200 - 2000 sps (.5 mil - 5 mil)

currently single channel

no local storage

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OpportunitiesExperiment design

40 by 40 grid ( 50 meter spacing )

3 component

4800 channels

200 sps

Challenges

30 Mbits/sec

350 GBytes/day

10 TBytes/month

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TA

2.5 Mbits/sec

20 Gbytes/day

0.6TBytes/mont

Ocean Bottom GSN StationsThere are noneStill large areas of globe uncovered by GSNAppropriate technology

Broadband OBS technology fairly advancedSatellite telemetry mature technology

Principal reasons for little progressRequired sites are very remote and often extreme weatherReal-time data acquisition requires surface “gateway”Deep ocean buoys costly to deploy and maintain Cost of deployment and maintenance

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A 3000 km Coverage Hole

WHOI Nootka Buoy Deployed 80 km off

Vancouver Island 2004-2005

Acoustical link to buoycollected 500kB-1MB/day

Iridium link to shore

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Neptune Canada

Axial Seamount RSN Science Workshop5-7 October 2011

OOI Regional Scale Network

0

Meters

3500

PortlandCyberPOP

MidPlate

Hydrate Ridge

Axial

Grays Harbor Line

NewportLine

Primary NodeLow Voltage NodeNode - no scienceCoastal mooring

30

An “outside-the-box” solutionUse current broadband OBS technology

Acoustic modems for ocean-column data transfer

Satellite telemetry for ocean-to-shore data transfer

Buoy-less real-time “gateway”

Ship-less deployment

Liquid Robotics Wave Glider

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Accomplishments

Demonstrated that WaveGlider™ can station-keepand transit with acousticcommunications(ACOMMS) payload

Demonstrated that WaveGlider™ can supportACOMMS to seafloorsensor

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Acoustic modem link

Iridium®

Seafloor sensor

Wave Glider™

Wall Street Journal 2010Front Page WSJSeptember 27, 2010

Modem Power RequirementsData acquisition rate 3 chan x /sec x 16 bits/sample =

48 bps. Let’s use 100 bps as design goal.With 4 kbyte packet accumulate 1 packet in 320s, so

270 packets/day.At acoustic modem rate of 2400 bps each packet takes

13.65s to xmit + 1.2s startup overhead ~15s. So 270packets/day takes 4050 s/day xmit time.At 20 W xmit power power required ~ 25 W-hr/day or ~

average 1 W power draw.OBS takes about another 1 W average

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Operational ScenarioDeployment by research vessel

Data collection via surface glider

2+ year operational life for bottom batteries

Abandonment or ‘sleep’ till vessel of opportunity passes

Investigate autonomous deployment …

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USA

Australia

USA

Australia

REPEATER

Seismometers Digitizer

UnderwaterCables

Internetaccess onseafloor

75 - 100 kmspacing

USA

AustraliaAcoustic link -2.4 kbits

Blue Greenlaser -

100 kbits+

Underwater meshnetwork

SummaryNeed to acquire data from all regions on planetData rates and bandwidth scale inversely with station

spacingMesh and ad hoc networking are possible if stations have

line of sight with othersBandwidth to Internet POP a limitation

Internet POPs are spreading rapidly in terrestrialenvironmentInternet POPs may become available in marine

environmentBound by physical limits of power, distance, and

line-of-sight

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