Download - IRIS
Download - IRIS
Download - IRIS
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Communications Enabling the Next<br />
Generation of Seismic Systems<br />
Frank Vernon<br />
2012 <strong>IRIS</strong> Workshop
Overview<br />
• Current use of communications in<br />
seismology<br />
• Technical requirements<br />
• Terrestrial communications<br />
• Marine communications<br />
• Summary
GLOBAL SEISMOGRAPHIC NETWORK<br />
KIP<br />
POHA<br />
JOHN<br />
XMAS<br />
RAR<br />
KDAK<br />
PTCN<br />
COLA<br />
FFC<br />
COR RSSD<br />
CMB<br />
NVAR<br />
WCI<br />
CCM<br />
HRV<br />
s PDAR<br />
SSPA<br />
ANMO<br />
PASC<br />
WVT<br />
BBSR<br />
PFO HKT<br />
TUC<br />
TXAR TEIG DWPF<br />
GTBY GRTK<br />
SJG<br />
SLBS<br />
ILAR<br />
PAYG<br />
RPN<br />
TGUH<br />
JTS<br />
MDTJ<br />
OTAV<br />
NNA<br />
SDDR<br />
BCIP<br />
LVC<br />
SDV<br />
ANWB<br />
BBGH<br />
GRGR<br />
PTGA<br />
SAML<br />
ALE<br />
SFJD<br />
CMLA<br />
MACI<br />
SACV<br />
RCBR ASCN<br />
KEV<br />
BILL<br />
BORG<br />
LVZ<br />
NRIL<br />
KONO<br />
TIXI<br />
YAK MA2<br />
OBN ARU<br />
ESK<br />
TLY<br />
GRFO<br />
KURK<br />
HIA<br />
MAKZ<br />
KIEV BRVK<br />
MDJ<br />
BFO<br />
KIV AAK<br />
PAB<br />
ULN<br />
WMQ<br />
BJT<br />
INCN<br />
ANTO GNI<br />
NIL LSA<br />
XAN SSE<br />
ABKT<br />
KBL<br />
KMI ENH<br />
SHEL<br />
KOWA<br />
MSKU<br />
KBS<br />
TSUM<br />
LBTB<br />
MBAR<br />
LSZ<br />
FURI<br />
RAYN<br />
KMBO<br />
ABP O<br />
UOSS<br />
MSEY<br />
PALK<br />
DGAR<br />
CHTO<br />
COCO<br />
MBWA<br />
PET<br />
YSS<br />
ERM<br />
MAJO<br />
TATO<br />
HKPS<br />
QIZ GUMO<br />
BTDF<br />
KAPI<br />
WRAB<br />
DAV<br />
2/2012<br />
PMG<br />
ATTU<br />
CTAO<br />
WAKE<br />
KWAJ<br />
HNR<br />
ADK<br />
TARA<br />
MIDW<br />
FUNA<br />
MSVF<br />
RAO<br />
KNTN<br />
AFI<br />
LCO<br />
TRQA<br />
TRIS<br />
SUR<br />
NWAO<br />
TAU<br />
SNZO<br />
EFI<br />
HOPE<br />
PMSA<br />
CASY<br />
MCQ<br />
VNDA<br />
WANT<br />
QSPA<br />
SBA<br />
<strong>IRIS</strong> / IDA Stations <strong>IRIS</strong> / USGS Stations Affiliate Stations Planned Stations
Global Seismic Network<br />
Telemetry<br />
• Essentially all stations have real time<br />
telemetry<br />
• Data used for real time processing by<br />
multiple users<br />
• Rapid earthquake notification<br />
• Source parameter estimation (location,<br />
magnitudes, ...)<br />
• Tsunami warning<br />
• Telemetry to nearest Internet POP<br />
• Satellite<br />
• Direct link
Regional Networks -Alaska
National and Regional Seismic<br />
Networks Telemetry<br />
•<br />
Essentially all stations have real time<br />
telemetry<br />
• Data used for real time processing<br />
• Rapid earthquake notification<br />
• Source parameter estimation (location,<br />
magnitudes, ...)<br />
• Tsunami warning<br />
• Telemetry to nearest Internet POP<br />
• Dedicated networks<br />
• Satellite<br />
• Mobile phone
PASSCAL Ad Hoc Telemetry
PASSCAL Ad<br />
Hoc Telemetry
USArray Transportable Array
Station Photos<br />
C35A Minnesota<br />
958A Florida<br />
142A Louisiana<br />
E27A North Dakota
Modularity in Communications<br />
Cellular Modem<br />
Solar VSAT<br />
AC VSAT<br />
• 96% Cellular<br />
• 3% VSAT
Telemetry Feasibility<br />
Sites are selected with the telemetry option as part of the plan.<br />
The available options in order of preference are;<br />
• Verizon digital service (EVDO)<br />
• AT&T (GPRS / GSM)<br />
• Radio to a VSAT located near AC Power<br />
• Radio to a location with AC power that has DSL or Cable<br />
Modem service available, not landowners.<br />
• Radio to a VSAT powered by solar panels.<br />
Radio range is 20 km line of sight. It is most often a few hundred meters.
VSAT<br />
• Works in remote locations<br />
• Slow connections<br />
• Longer to install<br />
• During Recon:<br />
• Check for 35 degree elevation<br />
angle, south-southwest<br />
• Locate near a power source<br />
(AC Plug)<br />
• Radio line of sight to seismic<br />
vault
Current telemetry<br />
Network<br />
Station<br />
Spacing<br />
Bandwidth<br />
# stas<br />
Station<br />
Power<br />
GSN ~2000 km ~5 kbit/s ~150 100+ w<br />
Reg/Nat 20 - 500 km ~20 kbit/s 20 - 300 5 - 100+ w<br />
TA 70 km ~5 kbit/s 450+ 6 w<br />
PASSCAL 0.02-100 km 0 - 30 kbit/s 10 - 1000 2 - 6 w
Current telemetry<br />
Network<br />
Station<br />
Spacing<br />
Bandwidth<br />
# stas<br />
Station<br />
Power<br />
GSN ~2000 km ~5 kbit/s ~150 100+ w<br />
Reg/Nat 20 - 500 km ~20 kbit/s 20 - 300 5 - 100+ w<br />
TA 70 km ~5 kbit/s 450+ 6 w<br />
PASSCAL 0.02-100 km 0 - 30 kbit/s 10 - 1000 2 - 6 w
Terrestrial Telemetry options<br />
Comm Type Power Distance BW bytes/Joule<br />
Wireless mobile 2 w ~20 km 300 kbs 19 kB/j<br />
Wireless Freewave 3 w 100+ km 154 kbs 6.4 kB/j<br />
Wireless Afar 5 w 50 km 2750 kbs 68 kB/j<br />
Satellite Wild Blue 30 w 1000+ km 50 kbs 0.2 kB/j<br />
Satellite Began 4 w 1000+ km 250 kbs 7.8 kB/j<br />
Satellite Iridium 5 w 1000+ km 2.4 kbs 0.06 kB/j
Current Realtime Data at DMC
Current Realtime Data at DMC
Goals<br />
• Transition to telemetry based systems<br />
• Near real time access to data<br />
• Better QC<br />
• Better data return<br />
• Access to data from remote sites<br />
• Connection to nearest Internet Point of Presence (POP)
Current Barriers<br />
• Power for PASSCAL type experiments<br />
• 2-30 W for comms<br />
• Bandwidth in remote areas<br />
• IRIDIUM<br />
• Installation<br />
• Additional equipment (antennas, cables, telemetry, time)<br />
• Line-of-sight to nearest neighbor or Internet POP<br />
• terrain and vegetation<br />
• Software configuration<br />
• automated initiation of dataflow (currently done on TA)<br />
• Transformation to streaming processing model from batch<br />
offline processing model
Opportunities<br />
• Radio and Satellite technologies are mature<br />
• Improvements being made<br />
• power management<br />
• efficient use of bandwidth<br />
• duty cycling<br />
• Communications for interstation spacings > 10 km<br />
• mobile<br />
• ad hoc networking<br />
• satellite<br />
• controlled by physics - line of sight, power
Present Mobile Coverage
Present Mobile Coverage
Opportunities<br />
Communications for interstation spacings < 1 km<br />
dedicated mesh networks<br />
exemplar company - wireless SEISMIC<br />
max 15000 channels<br />
up to 21 days of battery<br />
200 - 2000 sps (.5 mil - 5 mil)<br />
currently single channel<br />
no local storage
• Experiment design<br />
Opportunities<br />
• 40 by 40 grid ( 50 meter spacing )<br />
• 3 component<br />
• 4800 channels<br />
• 200 sps<br />
• Challenges<br />
• 30 Mbits/sec<br />
• 350 GBytes/day<br />
• 10 TBytes/month<br />
TA<br />
2.5 Mbits/sec<br />
20 Gbytes/day<br />
0.6<br />
TBytes/mont
Ocean Bottom GSN Stations<br />
• There are none<br />
• Still large areas of globe uncovered by GSN<br />
• Appropriate technology<br />
• Broadband OBS technology fairly advanced<br />
• Satellite telemetry mature technology<br />
• Principal reasons for little progress<br />
• Required sites are very remote and often extreme weather<br />
• Real-time data acquisition requires surface “gateway”<br />
• Deep ocean buoys costly to deploy and maintain<br />
• Cost of deployment and maintenance
A 3000 km Coverage Hole
WHOI Nootka Buoy<br />
• Deployed 80 km off<br />
Vancouver Island 2004-<br />
2005<br />
• Acoustical link to buoy<br />
collected 500kB-1MB/day<br />
• Iridium link to shore
Neptune Canada
OOI Regional Scale Network<br />
Grays<br />
Harbor Line<br />
Axial<br />
Mid<br />
Plate<br />
Portland<br />
CyberPOP<br />
0<br />
Meters<br />
Hydrate<br />
Ridge<br />
Newport<br />
Line<br />
Primary Node<br />
Low Voltage Node<br />
Node - no science<br />
Coastal mooring<br />
3500<br />
Axial Seamount RSN Science Workshop<br />
5-7 October 2011<br />
30
An “outside-the-box” solution<br />
• Use current broadband OBS technology<br />
• Acoustic modems for ocean-column data transfer<br />
• Satellite telemetry for ocean-to-shore data transfer<br />
• Buoy-less real-time “gateway”<br />
• Ship-less deployment<br />
• Liquid Robotics Wave Glider
• Accomplishments<br />
Iridium ®<br />
Demonstrated that Wave<br />
Glider can station-keep<br />
and transit with acoustic<br />
communications<br />
(ACOMMS) payload<br />
Demonstrated that Wave<br />
Glider can support<br />
ACOMMS to seafloor<br />
sensor<br />
Wave Glider<br />
Acoustic modem link<br />
Seafloor sensor
Wall Street Journal 2010<br />
Front Page WSJ<br />
September 27, 2010
Modem Power Requirements<br />
• Data acquisition rate 3 chan x /sec x 16 bits/sample =<br />
48 bps. Let’s use 100 bps as design goal.<br />
• With 4 kbyte packet accumulate 1 packet in 320s, so<br />
270 packets/day.<br />
• At acoustic modem rate of 2400 bps each packet takes<br />
13.65s to xmit + 1.2s startup overhead ~15s. So 270<br />
packets/day takes 4050 s/day xmit time.<br />
• At 20 W xmit power power required ~ 25 W-hr/day or ~<br />
average 1 W power draw.<br />
• OBS takes about another 1 W average
Operational Scenario<br />
• Deployment by research vessel<br />
• Data collection via surface glider<br />
• 2+ year operational life for bottom batteries<br />
• Abandonment or ‘sleep’ till vessel of opportunity passes<br />
• Investigate autonomous deployment …
Underwater<br />
Cables<br />
REPEATER<br />
USA<br />
Internet<br />
access on<br />
seafloor<br />
75 - 100 km<br />
spacing<br />
Australia<br />
Seismometers Digitizer
USA<br />
Blue Green<br />
Acoustic laser - link -<br />
100 2.4 kbits+<br />
Australia
Underwater mesh<br />
network
Summary<br />
• Need to acquire data from all regions on planet<br />
• Data rates and bandwidth scale inversely with station<br />
spacing<br />
• Mesh and ad hoc networking are possible if stations have<br />
line of sight with others<br />
• Bandwidth to Internet POP a limitation<br />
• Internet POPs are spreading rapidly in terrestrial<br />
environment<br />
• Internet POPs may become available in marine<br />
environment<br />
• Bound by physical limits of power, distance, and<br />
line-of-sight
Change language