1. Australian National Facility for Ocean Gliders
ANFOG:
Australian National Facility for Ocean Gliders

2. Basics of an Ocean Glider
Related to ARGO floats – but with wings
Powered by batteries (C or D cells)
Buoyancy engine – pumping oil or water into and out of a bladder changes density of vehicle which causes glider to sink or float
Wings provide forward momentum – motion through the water is a saw tooth pattern
Control via a rudder or movement of battery pack fore to aft and side to side

3. Ocean Gliders Description
Operation depth ratings 200, 1000, 5000 m
Designed for launch, monitor, recover or launch, forget, recover missions
Mission duration 15 days – 6 months
Speed < 1 kn - typically knts
Weight – kgs in air
Monitored and programmed at surface from control stations located on your desktop.
R/T communications at surface via radio link, Iridium, cell, Argos
Easily deployed and recovered from small boats or docks by 1 or 2 persons
Operations in all weather

4. Typical Glider “saw tooth” motion

5. Glider Manufacturers 3 groups in US building vehicles
Webb Research – Slocum Glider, Thermal Glider
UofW/APL – Seaglider
Scripps Institute - Spray Glider (now Bluefin)

6. Slocum Electric Glider
Manufactured by
Webb Research, USA

7. Slocum Gliders – Webb Research

8. Seaglider UofW / APL

9. Spray Glider – Bluefin Scripps

10. Spray Glider - Scripps

11. Development Timeline 1989 “The Slocum Mission” appears in Oceanography
1990 Office of Naval Technology (ONT) awards Webb Research Corporation contract for development of Slocum prototype
1991 Tests of Slocum prototype and thermal engine in Wakulla Springs FL and Lake Seneca NY
1992 First deployment of the ALBAC glider, a shuttle type glider developed at the University of Tokyo in the lab of Tamaki Ura. The ALBAC design uses a drop weight to drive the glider in a single dive cycle between deployment and recovery from ship. It uses a moving internal mass to control pitch and roll.
1993 Autonomous Oceanographic Sampling Networks paper appears in Oceanography

12. Development Timeline
1999 Slocum gliders tested at LEO-15 Observatory NJ
1999 Autonomous Ocean Sampling Network (AOSN) I conducted in Monterey Bay, CA to make oceanographic surveys. A prototype Spray operates for 11 days. Three Seagliders were also deployed in the bay.
2000 By this time all three gliders, Spray, Slocum, and Seaglider, have completed 10 day missions
2001 Spray glider makes 280 km section from San Diego
2002 Seaglider travels km off Washington Coast. Another Seaglider is deployed for month in storms off shelf near Seward Alaska
2003 January. Deployment of three Slocum gliders in the Bahamas by WHOI. Trials of prototype thermal Slocum conducted by WRC on same cruise

13. Development Timeline
2003 February. SPAWAR and the Canadian Navy conduct tests in the Gullf of Mexico of 3 Slocum electric gliders.
2003 August – September. AOSN II conducted in Monterey Bay CA. Gliders are used to make extensive oceanographic surveys over a six week period. Twelve Slocum and five Spray gliders are deployed during the experiment, to date the most gliders deployed for one project.
2004 September – November. A Spray glider travels across the Gulf Stream, beginning about 100 miles south of Nantucket, MA and arriving near Bermuda about one month later. The glider travels 600 miles, at a speed of about 0.5 miles per hour or 12 miles per day.
2004 Sea Gliders operate through a typhoon off east Asia
2005 Two Sea Gliders fly from Washington coast to Hawaii – 6 month mission
2005 Gliders launched from US Submarine

14. Ocean Glider Census – ~150 vehicles*
Seaglider
Spray
Slocum
No. in use 22 8 35
No. used
in-house
No. on order
15-20 12 50
* June 2006

15. Length 180cm, Diameter 30cm, Wingspan 100cm, Antenna 150cm
Slocum
Seaglider
Spray
Dimensions
Length 150cm Diameter 21.3cm
Length 180cm, Diameter 30cm, Wingspan 100cm, Antenna 150cm
Length 200cm, Diameter 20cm, Wingspan 110cm
Speed
~40 cm/s
~25 cm/s
~25-30 cm/s
Depth
4-200 meters
1000 meters
1500 meters
Endurance
30 days
1-6 months
815 cycles to surface
Power
Alkaline Battery
LiSoCl2 battery, 10MJ, 24/10V packs
52 Li CSC cells
Weight
52 kg
51.8 kg
Range
1,500 km
6,000 km km

16. Slocum Seaglider Spray ~35 degrees 8-70 degrees (1:5 - 3:1 slope)
Slocum
Seaglider
Spray
Data Transmission
RF Modem, Iridium satellite, ARGOS, Telesonar modem
Iridium satellite data telemetry, AMPS Cellular
Range
1,500 km
6,000 km km
Navigation
GPS, internal dead reckoning, altimeter
GPS-based dead reckoning,
GPS, Iridium satellite
Glide Angle
~35 degrees
8-70 degrees (1:5 - 3:1 slope)
19-25 degrees

17. Slocum Gliders

18. Benefits ‘cheaper’ to operate when cf with shipborne observations
Operations in all weather
Designed for launch, monitor, recover or launch, forget, recover missions
Telemetry rates via low earth orbit satellites are sufficiently inexpensive in both energy (~30 J/kilobyte) and cost (~$0.20/kilobyte) that the data return from a single glider (~120 kilobytes/day) is nearly that originally envisioned for the entire 3000-float Argo fleet using ARGOS while being a factor of ~200 less expensive.

19. Gliders are tools for appropriate Missions
Need to balance quality of data spatial requirements temporal requirements costs
to select best overall performance and value
Glider mission can be changed at any time

20. Sensor Capabilities Real-time data available through the web
Temperature
Conductivity
Salinity
Depth
Wavelength backscatter
Fluorescence sensor
Beam attenuation
Passive Acoustics
Real-time data available through the web
Delayed mode calibrated, QC data available

21. Slocum Electric Glider
Manufactured by
Webb Research, USA

22. Slocum Electric Glider
SENSORS
CTD (conductivity, temperature, depth) - SeaBird
Dissolved oxygen – Aanderaa Optode
Fluorescence: Chlorophyll-a, CDOM (coloured dissolved organic matter), Phycoerythrin - Wetlabs
Optical Backscatter:: turbidity through backscattered light at 470nm (blue), 530 nm (Green), 660nm (red).

23. Slocum Electric Glider

25. Glider Path: 22 days, 486 km, 2420 profiles

26. Depth-mean currents from glider

27. Glider cross-section: Sepia depression

28. Glider cross-section: Temperature

29. Glider cross-section: Temperature

30. Glider cross-section: Density

31. Glider cross-section: Backscatter

32. Glider cross-section: Temperature

33. Glider cross-section: Salinity

34. Glider cross-section: Temperature

35. Glider cross-section: Salinity

36. Glider cross-section: Density

37. Glider cross-section: Density

38. Investment plan Glider Purchase: 5 shallow (200m) and 5 deep (1000m)
(30%)
People: 3 people: glider preparation; Glider deployment and control; data provision (QC)
Glider deployments: Data transmission costs, shipping
Schedule: 2 shallow water gliders to be delivered in June 2007
2 deep water gliders to be delivered in November 2007
Others to come onboard in 2008.