Realtime Overthehorizon Communications for MBARI's Ocean Observing System

1
Real-time Over-the-horizon Communications for
MBARI's Ocean Observing System
2
Introduction
3
Introduction
4
Introduction

• MBARI Ocean Observing System (MOOS)
• Buoy
• AUV Dock
• Benthic Instrument Node (BIN)
• Stand-alone remotely deployable cabled
  observatory
• Delivers OEM cable to seafloor
• (Optical, Electrical, Mechanical)
• Good to 4km depth
• Targets low/mid-latitude deployments

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MOOS MTM2
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Relevent MOOS System Requirements

• Readily configurable / expandable
• Compatible with MARS/other cabled observatories
• Portable
• Large data storage capacity
• Real-time interaction
• Event response
• Signal to shore
• Initiate predefined actions
• Affordable

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Targeted MBARI Science

• Meteorological
• Upper Water Column (UWC)
• Nutrient supply impact on community structure
• Carbon export from euphotic zone to deep sea
• Ocean fertilization processes
• Benthic
• Microbial processes
• Fluid fluxes
• Geologic activity

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Target Deployment Locations
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MSE 2005 UWC Science Instruments

• WHOI ASIMET Suite
• WND, HRH, SWR, LWR
• MBARI Delta pCO2
• 7x HOBILabs HydroRad HydroScat
• 11x Seabird CTD
• RDI ADCP
• MBARI Environmental Sample Processor (ESP)
• MBARI Bathyphotometer
• MBARI OSMO

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MSE 2005 Surface-Node Block Diagram
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MSE 2005 Benthic Science Instruments

• Seabird CTD
• Wetlabs ECO BBD FLD
• RDI ADCP
• MBARI ISUS
• MBARI OSMO
• MBARI SEISMO
• Prime Focus Sediment Trap
• MBARI Respirometer
• Vertical Profiler
• MBARI Seafloor Cam

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Instrument Sample Schedule

• Instruments powered/sampled periodically
• Most every 10 minutes
• Some every hour
• Few continuously

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Data Requirements As Planned

• Multi-scale Oceanographic Processes 3.3MB/day
• Canyon Processes Normal 257kB/day
• Canyon Processes Event 1.3MB/day
• Active Mid-Ocean Ridge 71.3MB/day
• Benthic Carbon Cycles 3.3MB/day
• Standardized Baseline 1MB/day

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MOOS Mooring Controller (MMC)

• CPU based on Intel StrongARM
• Embedded Linux RTOS running Java application
• Java RMI
• Provides telemetry services
• Retrieval
• Archival
• Transmission control
• Bi-directional shore/instrument interface
• Up to 12A per channel power switching/isolation
• Multinode support via copper/fiber Ethernet

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Radio Integration

• RF Interface Card (RFIO)
• Two 9-pin RS-232 ports
• 1 Primary radio
• buoy ?? shore
• 1 Secondary radio
• buoy ?? buoy
• buoy ?? AUV
• buoy ?? ship
• Isolated 10W power supply
• Separate ground-fault detector

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Buoy / Seafloor Network
Primarily Star Topology
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Buoy/Shore Network
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Telemetry - Data Publishing

• Buoy dials shore modem periodically
• Buoy establishes PPP link to portal computer
• Portal publishes buoy DNS information
• Buoy publishes recently archived data on portal
• Buoy disconnects
• Portal publishes data to shore-side data system
  (SSDS) through firewall

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Telemetry Instrument Services

• Buoy dials shore modem periodically
• Or RF reset initiated
• Buoy establishes PPP link to portal computer
• Portal publishes buoy DNS information
• Shore computer opens remote console on buoy via
  ssh
• Shore computer establishes console to instrument
• Remote instrument configuration
• Remote instrument diagnostics
• Remote driver updates
• Add instrument and remotely start instrument
  service
• Etc.

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Systems Considered

• Iridium
• Globalstar

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Deployment Location Evaluation
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Data Transmission Price - Planned

• Iridium _at_ 2.4kbps
• Globalstar _at_ 7.4kbps

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Globalstar Testing Integration

• Qualcomm GSP-1620
• Prevco housing
• PVC case
• Acrylic window
• Data port to MMC RFIO
• Testing results
• Reliable 7.6kbps for IP traffic over PPP link
• No significant impact seenfrom buoy motion
  simulation

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Globalstar Integration - EMC

• Transmitters
• BT Console 2.4GHz
• Globalstar 1.6GHz
• Freewave 900MHz
• ARGOS 401MHz

• Receivers
• Globalstar 2.4GHz
• BT Console 2.4GHz
• GPS 1.575GHz
• RF Reset 929MHz
• Freewave 900MHz

• Separated Globalstar GPS by 1.2m
• Requires gt0.76m separation
• Console RF Reset separated by 2m
• Removed Bluetooth Console Repeater

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Iridium Testing

• NAL Research
• 9500 Iridium Modem
• Model CDM9500I35-I
• Fixed Mast Antenna
• Model SAF5350
• 0.5dB 0 to 40
• 1.5dB 40 to 70
• 0.5dB 70 to 80
• 0.0dB 80 to 90
• -2.0dB 90 to 110
• Buoy spends most time between 0 and 20
• ASIMET WND data from MTM2

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Iridium Testing Results

• FTPd multiple small files of varying formats
• .zip, .jpg, .gif, .pdf, .txt, .rtf, .c, .tar,
  .gzip
• Filesizes from 1.5kB to 15.0kB
• Tilted antenna to predefined heading and angle to
  simulate buoy motion
• Dial-up only
• Transferred large text files
• 100kB to 1MB

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Iridium Testing Results Small Files

• Dial-up data service (tested in Linux)
• AVE 2.04kbps, MAX 6.00kbps, MIN 1.28kbps
• Direct Internet service (tested in Windows)
• Compression from Brand Communications
• AVE 6.76kbps, MAX 26.24kbps, MIN 1.36kbps

Plain Text
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Iridium Testing Results Filesize Tilt

• Noticed lower bandwidth at low angles than at
  high angles
• Suspected antenna gain pattern

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Iridium Testing Large Files

• Direct Internet
• MAX 15.0kbps
• AVE 13.9kbps
• MIN 13.1kbps
• Dial-Up
• MAX 2.6kbps
• AVE 2.5kbps
• MIN 2.2kbps
• Dropped link 4 times out of 16 at around 600kB

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Iridium Testing Compression

• Large files compressed down with WinZip
• 100kB to 1.24kB
• 500kB to 3.391kB
• 1.023MB to 6.055kB
• Direct Internet really
• MAX 182bps
• AVE 116bps
• MIN 79bps
• Due to online time lost during data compression
• Better to compress data then send

• Dial-Up should be
• MAX 3.3kbps
• AVE 2.8kbps
• MIN 1.8kbps

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Iridium Testing - Conclusions

• Use optimized antenna for application
• Transfer small files
• Transfer precompressed files

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Iridium Integration

• Changed components based on previous testing
• Motorola 9505 Phone
• Antenna adapter
• Data Kit
• Auto-on Modification
• Michael Ashley
• Auto Adapter
• Compatible with buoy power
• Mobile Antenna
• 1.0dB 0 to 40
• 0.5dB 40 to 70
• -0.5dB 70 to 80

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Iridium Integration - EMC

• Transmitters
• Iridium 1.6GHz
• Console 900MHz
• ARGOS 401MHz

• Receivers
• Iridium 1.6GHz
• GPS 1.575GHz
• RF Reset 929MHz
• Console 900MHz

• Separated Iridium GPS by 1.2m
• Untested
• Console RF Reset separated by 2m

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New Pricing Plans

• Iridium

• Globalstar

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Data Requirements As Deployed

• CIMT in Monterey Bay 4.1MBdata/day
• MTM2 in Monterey Bay 1.1MBdata/day
• With link overhead
• Link overhead 6 to 1
• On MTM2 really using 120minutes/day
• 3650 min/month
• Upgraded to 3000min/month plan
• 7325/year with Globalstar

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Future Plans

• Reduce link overhead
• Implement shore initiated link establishment
• Deploy Iridium on buoy in region outside
  Globalstar service area

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MOOS Buoy Team - Primary

• Keith Raybould Program Manager
• Mark Chaffey Systems/Project Engineer

• Software Engineering
• Kent Headley
• Bob Herlein
• Tim Meese
• Tom OReilly
• Wayne Radochonski
• Mike Risi

• Mechanical Engineering
• Jon Erickson
• Andy Hamilton
• Electrical Engineering
• Scott Jensen
• Lance McBride
• Ed Mellinger

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Thanks to

• Sanjeev Uruppattur
• Duane Thompson
• Mark Chaffey
• Tim Meese
• Russ Light, APL