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Seismic Instrumentation Technology Symposium
Communications - Leveraging Existing Infrastructures with Iridium RUDICS and SBD
Derek Inglis
June 16-17 2011
Background in Seismic Telemetry
IRIS/Passcal – RT130 / Argos- Quanterra Q330 / Iridium
Seismic and GPS data fromremote polar regions
XI-100 and XI-202
Satellite Telemetry Systems
Good choice for seismic monitoring• Disaster ready, don’t rely on cellular or
landlines• Will work in areas where there is no other
infrastructure (extreme regions)• Costs are coming down (slowly)• Geostationary Systems• Low Earth Orbiters (LEO’s)
GEO/LEO
• Geostationary Satellite systems– Track the same positions on the earth– Large orbits– Usually directional antennas (VSAT)
• Polar Orbiting satellite systems– Orbit North to South– Smaller orbits– Can use omnidirectional antennas
Satellite Systems
Argos InmarsatGOES MSATOrbcomm Iridium VSAT Globalstar
Satellite systems available
GOES, Meteosat
Messaging
GEO < 5 kB/day
Argos Messaging
LEO < 5 kB/day
Inmarsat C Messaging
GEO < 10 kB/day
Orbcomm Messaging
LEO < 50 kB/day
Iridium Voice/Data/Messaging
Big LEO 1 MB/hr
Globalstar
VSAT
Voice
Internet
Big LEO(regional)
Big LEO
1 MB/hr
10-30 MB/hr
Inmarsat BGAN Internet GEO 50 MB/hr
Iridium overview
• Designed as a phone system: 2-way, real-time• 24/7 availability, true global coverage
– 66 satellites– Inter-satellite links pass traffic to ground station
• Basic data rate 2.4kbps
• Various modes of access– Dial-up (better for larger file sizes)– Short Burst Data, SBD (up to 2 kbyte per message)– RUDICS
Cross-linked satellites
XI-100
• Short Burst Data + RUDICS• Can connect directly to a Q330 via IP or serial
port• External sensor port
XI-100 Functional Diagram
XI-100
Cold Temperatures
• Original A3LA modems spec’d to -20C• Newer 9522B’s spec’d to -30C• Need to assist modems by adding heater
circuits
Customization of Iridium modems
• Internal Heaters for cold temperature • Tested to -70C
Confidential Information - Xeos Technologies Inc. - NOT FOR DISTRIBUTION
Iridium RUDICS
Benefit over non-rudics CSD type calls
• Allow for TCP/IP and UDP connectivity• More reliable connection• Slightly better transmission rates• Eliminate modem to modem• Least expensive data cost per KB
RUDICS system
• Consists of a ‘Tunnel’ server application
• Remote Seismic monitor connected to an XI-100
Data CollectionSoftware
Iridium Gateway
IridiumSatellite
Xeos XI-100
Remote Device (GPS, Seismic, etc)
Internet
Xeos XI TunnelSoftware
Data CollectionSoftware
Xeos XI-100
Remote Device (GPS, Seismic, etc)
Xeos XI TunnelSoftware
We bridge a remote network in the field to a local network back home via our XI-100 and an
Iridium satellite connection.
Data CollectionSoftware
Remote Device (GPS, Seismic, etc)
This gives you access to remote data as if you were directly connected to your device in the field
Data CollectionSoftware
Xeos XI TunnelSoftware
Xeos XI Tunnel Software
· Python based web solution (runs on almost any Operating System)· Supports HTTP connections and UDP connections to remote devices· Allows automated data collection via execution of user generated shell scripts· Allows viewing status of health for remote XI-100· Allows connections to multiple remote sites concurrently
Rudics problems Buffering data over a very slow connection - We overcame this on the
firmware side by buffering data in flash memory
TCP/IP Stack on a low power, low memory device - We stripped down the stack to the bare essentials to make it work within the confines of the hardware
RUDICS drops - We overcame these by implementing a handshake system between the XI and the tunnel to detect drops and reestablish the connection.
We also discovered an issue with stop bits that seemed to impact RUDICS
drops.
XI-202 (coming soon!)
• Smaller, lower cost• SBD only• Status of Health (SOH) message and more• GPS, accelerometer (motion and tilt)• 8 MB flash memory• External sensors Inputs• External Inputs/Outputs
XI-202• Monitor multiple
battery voltages• Collect, store, transmit
small data samples• Send and receive
commands from equipment
• External Reset other equipment (kickstart)
Polarsat – beyond Geostationary coverage
29
Telesat’s Global InfrastructureTelesat is now the fourth largest Fixed Satellite Service (FSS) operator in the world providing reliable and secure satellite-delivered communications solutions to broadcast, telecom, corporate and government customers
The need for circumpolar coverage
Meteorological
• Continuous Circumpolar Coverage 100% at 60° North and above for weather monitoring
Communications
•Current Area of Interest outlined in blue as defined by the Canadian Space Agency
•Coverage can be expanded to include other arctic regions
•Satellite could also include:
• aviation communications
• navigation augmentation,
The Telesat Approach to Polar Constellation
• A two satellite constellation can meet these requirements for continuous weather monitoring and communications
• Satellite design life of 15 years in a space environment similar to geostationary orbit where we currently operate our 13 satellites
• A private public partnership model based on payment of services over the period in which these services are provided
• Commercial approach to the development, procurement and operation of the satellite system
• Can provide over ten hours of broadband communications service to the south pole region
Comparison of Telesat proposed orbit and geostationary orbit.
Thank-You