Transcript Torpedo Defence Presentation

DRDC Aspects of SW06 – 2007 Workshop
Sean Pecknold, Paul Hines, John Osler, Victor Young, and Dale Ellis
Maritime Environmental Awareness Group, DRDC Atlantic
31 January, 2007
Defence Research and
Development Canada
Recherche et développement
pour la défense Canada
Canada
Outline
• Data acquired
– Propagation loss
– Swath bathymetry
– FFCPt
– WBS and WARBL
• Data needed
• Anticipated output/collaborative efforts
• Other results
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Propagation loss
• Sources
– MSM
– Shipboard projector
• CWs, 200 Hz LFMs @ 1.2 and 3 kHz
• Receivers
– 2 GPS enabled SBs
– Moored UAT – 8 h/p between 22 m and 51 m depth –
24kHz sampling rate
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Propagation loss runs
-73.40
-73.30
-73.20
-73.10
-73.00
-72.90
-72.80
-72.70
39.4
WBS (bottom)
Current moorings
39.13.182N
72.54.462W
New ADCP
39.3
cHIRPS
BBNs
Mooring lines
UATdep
39.2
ADCP
FFCPT drops
sonobuoys
39.07.170N 73.16.638W
39.1
39.01.176N
73.03.276W
39
BBNs
38.9
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Local measurements
Reson 8125
• 455 kHz, 120
metre range
• 240 cross-track
beams (0.5º)
Next Figure
• 1º along-track
beam width
• 6 mm depth
resolution
• DGPS, Gyro,
pitch-roll-heave
• Pole mount on
Quest
2000 m
R&D Canada
– Atlantic
R & D pour
la défense
Canada – Atlantique
Hull mounted Defence
EdgeTech
X-Star
Chirp• Profiler
(2-16
kHz)
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Multiple drop FFCPT transects
seabed and water column measurements
Sound speed (m/s)
1470
1480
1490
1500
1510
1520
1530
0
10
20
CTD 2
CTD 3
XSV Aug 1
XBT Aug 1
BBN Targets
CTD 4
CTD 5
Depth (m) .
30
CTD 6
CTD 7
CTD 8
40
CTD 9
CTD 10
CTD 11
50
CTD 12
CTD 13
CTD 14
60
70
80
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Initial scattering results from SW06
Strataform Scattering
Strength Result
Hines et al., (2005)
SW06 Energy Time Series – in
process of calibration
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Wide Angle Reflection and Bottom Loss
• Bottom loss is the angle-fitted source level,
calculated from direct arrival, minus received level
minus theoretical transmission loss from a
perfectly reflecting bottom (technique of Holland
and Osler, 2000).
FFCPt1
FFCPt2
WBS July 24
WBS July 25
sonobuoys
BL = SL - RL - TL
BOTTOM
REFLECTED
Time
DIRECT
SOURCE


RECEIVER
Range
1-12 kHz source
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Data needed
• Sensor data from moorings (23 July – 2 August)
• Shipboard met data, CTDs/XBTs (available on DVD)
• Other acoustic data from 25 July – 2 August; ambient noise
and propagation (available from WHOI)
• MSM source levels
• Sediment acoustic properties
– Chirp runs along propagation paths/WBS area (Turgut)
– Sediment mapping (Miller)
• Roughness measurements (IMP) in APL-UW area (Tang)
• Core data from FFCPt drop areas for comparison
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Anticipated output/collaborative efforts
• Scattering strengths and roughness, with Tang
• Analysis of WARBL data for bottom loss at varying
angles and comparison w. Dahl
• Comparison of FFCPt measurements to inversion
results (Chapman and others)
• Propagation sensitivity to oceanographic and
geoacoustic parameters, with Dosso (UVic)
• Improvement of model predictions based on REA –
2007 Maritime Acoustic Symposium
(CFMWC/METOc)
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
Other results
• Successful REA operation with reachback to
DRDC
• Auralization data from BBN targets
• In-air vs. in-water sound levels for Convair flyover
• Ship noise levels
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique
The Defence Research
and Development Branch
provides Science and
Technology leadership
in the advancement and
maintenance of Canada’s
defence capabilities.
Defence R&D Canada – Atlantic • R & D pour la défense Canada – Atlantique