anchor synergies with global-scale efforts bruce m. howe acoustic navigation and communication for...

ANCHORSynergies with Global-scale efforts

Bruce M. Howe

Acoustic Navigation and Communication for High-latitudeOcean Research (ANCHOR) Workshop

Applied Physics Laboratory, University of Washington,

27 February – 1 March 2006

Outline of Talk

• A little history and background

• ASA Integrated Acoustics Systems for Ocean Observatories

• GPS

• ORION status

• ORION acoustics

• Connection to ANCHOR

History• Sun, moon, stars, terrain/feature tracking• Compass, sextant and variants• Time – longitude• Time standards – 1930s Einstein’s predictions of effect

of gravity on time. Nobel Prizes: Rabi 1944 atomic resonance; Ramsey 1989 hydrogen masers

• Radio, loran, mini-ranger, … • Satellites

– Sputnik – Doppler navigation– Transit satellites 1965 (a few fixes/day, 15 min integration) for

Polaris subs– GPS – one Sept weekend, 1973, full coverage time and space

• Deep space network – nav and comms -> deep space internet, infrastructure around Mars, occultations

• Underwater – SOSUS, Navy ranges, LBL, FLBL, Swallow/SOFAR/RAFOS/mobile/tomography

Acoustics in Ocean Observatories

• Acoustic methods will be ubiquitous in ocean observing– Ocean is transparent to sound, but largely

opaque to electromagnetic radiation– Provides synoptic, volumetric sampling

• Cross cuts across many disciplines – opportunities for synergies and integration

Integrated Acoustics Systems for Ocean Observatories (IASOO)

OceanAcoustics

GPS/cellConcepts

OceanObservatories

IASOO

Science Communication

Navigation

Unified architecture across all scales

ASA-AO committee

2003

IASOO Concepts• Acoustic sources act as “GPS satellites” underwater to

provide signals for – Navigation– Communication – Science

• Receivers on all platforms• Simultaneously

– Ambient sound (wind, rain, seismic, whales, shipping, …)– Tomography– Others

• 2-way communications as appropriate• Manage the acoustic spectrum – all users• Unified architecture across all scales

ORION Workshop

ice• Jan 2004 Puerto Rico

• Recognized as part of observing system

Projection slice theorem

Norton: – if sensors only on periphery, only get vorticity, not divergence

Global Navigation Satellite Systems

GPS GlonassGalileo

---------------

60–90sourcesin space

GEONET

Japanese Meteorological Agency, 2003

Maps of Precipitable Water (PW)

GPS Experience

• Huge user base has evolved• >3000 science receivers – international data

centers• GPS Navigation message

– 50 b/s, 20% parity bits, 1 of 10 words for sync, 30 s– Clock correction– Ephemeris (orbits/position/velocity)– Ionospheric correction parameters– UTC information– Almanac

• Differential measurements, WAAS, quality, …

Back to the ocean

• Major NSF Ocean Sciences Program started 2004

• Infrastructure MRE funds $309M in FY2007!!!

• PLUS all science, O&M, DMAS, E&O, … 30 years

• www.orionprogram.org

Elements• Sustained presence – research and operations

– power and comms (x,t)

• Three Components– Regional, cabled +– Coastal, cabled, moor, +– Global, Moorings NSF

ORION

IOOS

Distributed sensor systemNavy example

• Environmental assessment defines cluster topology and fixed/mobile mix

• Fixed and mobile sensor nodes deployed for optimum coverage. AUV’s enter semi-dormant state as temporarily fixed or drifting nodes

• Reconfigure mobile sensor nodes based on current environmental situation

• Event detection communicated to network (ACOMMS or RF)

• Mobile platforms respond

NEPTUNE – in progress• NEPTUNE

Canada• Install summer

2007• 2-4 nodes, to

Endeavor• Loop design• CDN$40M• With Alcatel

• Test beds• MARS and

VENUS

Mid-2006

Mid-2006

Late 2005

ORION RFA concept proposals• 5 major acoustic, 12 others, 17 acoustic out of 48 total –

ORION recognizes acoustic components• Worcester et al.: Thermometry, support navigation, ambient

sound, t-phase• Duda et al.: float tracking (process studies) and thermometry• Detrick et al: geophysical, called for bottom/sofar hydrophone,

Stephen et al – sofar t-phase• Daly et al., Barth et al.,: NEPTUNE/coastal multipurpose

mooring array, tomography• Horne/fish/mammals• Bioacoustics observatory/hawaii• 3 ambient sound (1 with CO2)• Small scale tomo/vents• Many with gliders and AUVs with navigation implied

Daly et al.

• Water column oceanography

Worcester et al• Thermometry

• Also navigation

Duda et al

• Precise float tracking

• Dispersion

• Meridional overturning

• Thermometry

Alternate Source Test (AST)

• 28 and 84 Hz• Simultaneous signals, phase locked (3rd harmonic)• Source from DP ship, DGPS• Deployed in deep water near Pioneer Seamount, 1995

Main Points• Applicable to all cases:

– Timing is fundamental– Navigation implies communications– Tomography results (sound speed and velocity)– All signal compatible– Ambient noise – spectrum, marine animals– GPS is a good analogy– Work to inexpensive receiver– Modeling and data assimilation crucial – start/continue now– Equipment needs (Arctic and lower latitudes) are similar

• Arctic Data N ~ S x R, say S = 5(6)– Fixed N = (5 x 4) / 2 = 10 (15)– Add 16 tethered (x,t known), add N = 5 x 16 = 80 (96)– Add 32 mobile (x,t unknown), add N = (5-3) x 32 = 64 (96)– Total – 154 (207) independent ocean samples each ping

Path

• Need roadmap

• More funding!

• Next MREs, other, …

• Expect 10 years for big chunks – BUT play up short, critical time frame