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 from
remote 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
GOES
Orbcomm
VSAT
Inmarsat
MSAT
Iridium
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 Big LEO
/Messaging
1 MB/hr
Globalstar
Voice
1 MB/hr
Big LEO
(regional)
VSAT
Internet
Big LEO
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
Iridium
Satellite
Internet
Remote Device
(GPS, Seismic, etc)
Xeos XI-100
Iridium Gateway
Xeos XI Tunnel
Software
Data Collection
Software
We bridge a remote network in the field to a
local network back home via our XI-100 and an
Iridium satellite connection.
Remote Device
(GPS, Seismic, etc)
Xeos XI-100
Xeos XI Tunnel
Software
Data Collection
Software
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 Collection
Software
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
Xeos XI Tunnel
Software
Data Collection
Software
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
Infrastructure
Telesat 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.
jrigley@telesat.com
Thank-You