Global Network and Telemetry Experience

REF TEK is the supplier to the University of California, San Diego for the IDA program, which is a major portion of the IRIS/GSN program.

REF TEK started supplying digital telemetry for seismic applications in 1981, when it was approached by UCSD to supply digital telemetry for the ANZA Network, the first such network in the USA. Since then, REF TEK has been supplying error-corrected digital telemetry for regional and national networks for research and public safety purposes worldwide. Until very recently, REF TEK has been the only commercial supplier of error-corrected digital telemetry. Now most investigators understand the problems introduced in processing by bit errors, including finding automatic phase picks.

The Southern Great Basin Seismic Network (SGBSN) is a large 42 station network that monitors seismicity around the Yucca Mountain, Nevada large nuclear waste disposal area. It is operated by the University of Nevada, Reno. The geometrical concept for this network has been to deploy radio telemetry subnets with nodes (or hubs) that then forward the data to Reno via microwave. At Reno, the acquisition and processing is accomplished on SPARC workstations. Originally, when part of the network was first deployed by the US Geological Survey, the nodes transmitted via satellite (VSAT) to the USGS National Earthquake Information Center in Golden, Colorado. This network emphasizes three relevant aspects: the hub concept, the use of a UNIX workstation in communication and acquisition, and satellite communication.

The Geological Survey of Japan (GSJ) Network is a 16-station network deployed around the Kobe area to record aftershock seismicity. The communication vehicle is ISDN digital lines, and the processing is on UNIX workstations. Although, this network uses computer interfaces with REF TEK DAS units, nevertheless it demonstrates the use of REF TEK instruments with links other than narrow band, voice-grade phone lines or radios and the use of workstations for communication and acquisition.

The table below is a list of digital telemetry networks supplied by REF TEK.

REF TEK’s innovation in network technology, the Advanced Seismic Networks approach, offers customers telemetry stations and networks for a variety of communications media including IP networks, satellite and radio telemetry, analog and digital lines. The two most recent installations in Table 1 utilize the Advanced Seismic Networks approach.

DIGITAL TELEMETRY NETWORKS SUPPLIED BY REFRACTION TECHNOLOGY, INC.

Date Description of Network Organization Operating Network Communication Media
1981

ANZA Network

University of California, San Diego, Scripps Institution

UHF, Microwave

1983

Four networks in Italy

ISMES, Bergamo

UHF

1985

Parkfield High Frequency Array

University of California, Berkeley

UHF

1986

Portable Telemetry Array

University of California, Lawrence Livermore Laboratory

UHF

1987

Parkfield Early Warning Network

US Geological Survey, Menlo Park

UHF

1987

The Geysers Network

University of California, Lawrence Berkeley Laboratory/US Geological Survey

UHF

1987

Parkfield Differential Ground Motion Array

US Geological Survey, Menlo Park

Cable Telemetry

1988

Perry Nuclear Power Plant Network

Cleveland Electric Illuminating

UHF

1988

IDA (International Deployment of Accelerometers)

University of California, San Diego, Scripps Institution

Global Dial-up

1989

SMU Deployable Array

Southern Methodist University

UHF

1990

Kyrgyz Telemetry Network

US/Russia Joint Seismic Program

UHF (now upgraded to spread spectrum radio)

1990

Kyrgyz Dense Telemetered Array

US/Russia Joint Seismic Program

UHF (now upgraded to spread spectrum radio)

1992

Southern Great Basin Network

University of Nevada, Reno

UHF, VSAT

1994

Virginia Network

Virginia Polytechnic Institute (Virginia Tech)

UHF

1994

Nuevo Cuyo Network

INPRES, Argentina

VHF/UHF, dial-up

1995

Southern Great Basin Network

University of Nevada, Reno (additional stations)

UHF, VSAT

1995

Chile Network

University of Chile

UHF

1996

Kuwait National Network

Kuwait Institute for Scientific Research (KISR)

UHF

1996

Nor-Oeste Argentino

INPRES, Argentina

VHF/UHF, dial-up

1996

Kobe Network

Geological Survey of Japan

ISDN

1997

Friuli Network

Instituto Nazionale de Geofisico/Civil Protection, Italy

Dial-up

1997

Thailand National Telemetry Network

Thailand Meteorological Dept.

VSAT, Dial-up

1997

Kobe Network

Geological Survey of Japan (expansion)

ISDN

1997

San Calixto, Bolivia Network

San Calixto Observatory

UHF

1998

Puerto Rico National Telemetry Network

University of Puerto Rico, Mayaguez

UHF, microwave, ISDN

1998

Tsunami Warning Network

US Geological Survey, Golden, Colorado

UHF

1999

New Delhi Telemetry Network

India Meteorological Department, Delhi, India

VSAT

2000

Seismographic Aftershock Monitoring System (SAMS)

Test Ban Monitoring

Spread Spectrum radio

2000

Small Aperture Infrasound array

Federal Institute for Geosciences and Natural Resources, BGR (Bundesanstalt fuer Geowissenschaften und Rohstoffe), Hannover, Germany

GSM

2002

Seismograph Telemetry Network around Edinburgh

British Geological Survey

UHF

2004

Seismic Telemetry Network

Institute of Physics of the Earth (IPE), Masaryk University, Brno, Czech Republic

Spread Spectrum Radio

2005

National Operative Telemetry System for Seismological Information (NOTSSI)

Geophysical Institute Bulgarian Academy of Sciences, Sofia, Bulgaria

ISDN, VPN, MAN

2006

DAM monitoring system

EDELCA,Venezuela

Spread Spectrum Radio

2006

German Indonesian Tsunami Early Warning System

GeoForschungsZentrum Potsdam (GFZ)

Global VSAT communication

2007

Dam Monitoring Telemetry network

Theri Hydro Dam Corporation, India

Spread Spectrum Radio

2008

Zaragoza Bridge Monitoring system

Direccion General de Obras Publicas del D.F. & Terracon, Mexico City, Mexico

Spread Spectrum Radio

2009

Jordan National Seismic Telemetry network

Jordan Seismological Observatory (JSO), Amman, Jordan

VSAT