Blue
Planet - BP'07 sea trial
21 April - 2 May 2007, South Elba,
Italy.


1. Objectives: the BP'07 sea trial is part of the Maritime Rapid
Environmental Assessement effort and represents a multi-institutional
cooperation that fulfill a number of complementary objectives under
several
project and respective work programmes. For UALg this sea trial follows
a number of previous experiments on this series that have started in
2003 with MREA'03 (North Elba, Italy) and in 2004 with MREA'04 (west
coast of Portugal) under the AO-BUOY Joint Research Project with NURC.
The overall objectives are to:
- test low - frequency tomography and geoacoustic inversion with a
network of light acoustic-oceanographic
buoys (AOBs);
- acquire acoustic data to allow testing at the sea an integrated
system of acoustic tomography for “Rapid Environmental Assessment
(REA)”;
- acquire environmental, water column, sea bottom and
metereological
data before, during and after the sea trial to allow the validation of
the inversion results and allow their assimilation into generic
models for REA.
2. Participating vessels
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Hr Ms Snellius (NLHO-Dutch Navy)
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Snellius Launch
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RHIB from Snellius
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NRV Leonardo (NURC)
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3. Means to be employed a board the various platforms
- 2 AOB's with 8 and 16
hydrophones and 20 temperature sensors
- 2 sparse arrays 4 and 5 hydrophones
- CTD
- X-star subbottom profiler
- Uniboom subbottom profiler
- Low frequency sound source
- OEX auv
- REMUS auv
- waverider buoy
- Lubell 1424HP sound source
- MPV
- multibeam
3. Test area:

4. Operations day by day (all times are in local italian time
= GMT
+ 2)
SATURDAY 21/April - equipment load in Portoferraio (Elba
Island). Antenna's mounting, equipment installation and first checking
on deck.
SUNDAY 22/April/2007
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09:00
leave Portferraio direction south to
work area. 13:00 deploy sloop for acoustic runs nearby point B. 13:45
make CTD on point P; 14:20 deploy AOB2-002 (16 hydrophones);
14:40 deploy X-star and turn around to the north and take P-Q line,
start transmitting (30 ms LFM chirps 500 - 7000 Hz), X-star depth is
very approximative but depth sensor reads 11m; 14:50 ship accelerating
to 4 kn and going from P to Q; 15:30 passing close to AOB on left
side; 16:15 lost contact with AOB; 17:00 recovering X-star after
point Q; 17:15 CTD on point Q. 17:30 going up from Q to P; 18:10 pass
at 9 kn close by AOB on the right side; 18:15 turn to pick up sloop;
19:00 pass by sloop; 19:15 pick-up sloop; 19:30 looking for AOB; 20:00
recover AOB.
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1.
the AOB is at sea and is beaing monitored with the PDA |
2. perfect deployment of the AOB from
Snellius. |
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During night time Snellius was doing MVP and multibeam sonar since TNO,
CTD had problems.
MONDAY
23/April/2007

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09:30
deploy sloop at 1km of point A; 09:30 -
Leonardo is at A point getting ready to transmit, source at 80 m depth;
11:30 deploy AOB22 off A-B line at 2 nm from point A; 13:30 deploy
AOB21 off A-B line at approx 3 nm from point A; start doing uniboom
along A-B transect; 17:45 recover uniboom; 18:15 recover sloop; 17:45
recover AOB22; 17:20 recover AOB21; unfortunetely AOB21 did not work
due to battery failure at deployment. The same buoy also had a problem
on GPS synchro.
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AOB22 - hyd1, clear multipath
and multitones
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AOB22 - hyd10, inverted image of
low freq chirp;
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During night time Snellius was doing uniboom along pre determined track
on the upper part of the box.
TUESDAY
24/April/07

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08:00
- the buoys where on charge during the night and are now full charged;
after switched on they are both up and running; 09:00 still doing
seismic survey; deploy AOBs along the A-B transect and then RIHB:
station 13 - RIHB (11:15), station 17 - AOB21 (11:30), station 21 -
AOB22 (10:35); Leonardo should be in position at 09:30; start uniboom
and make runs on land side; 17:20 recovering RHIB; 17:50 recovering
AOB21; 18:20 recovering AOB22.
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BP07
working area
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Deploying
the AOB21
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CTD survey during the night and multibeam.
WEDNESDAY
25/April/07
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Acoustic patches program:
Leonardo at points F1, F2 and F3; RHIB/Sloop deployed at E1, E2 and E3
at 11:00 ; AOB22 deployed at G1 at 11:14; AOB21 deployed at G2 at
11:45; doing X-star, starting at point B and doing up and down on
boomer tracks and then in between the tracks; went for recover of AOB21
at XX and then AOB22 at YY; 07:00 - tried to grab a bottom sample but
did not succeed to close the sampler (too deep too light).
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Deploying
TNO's bottom sample graber |
Bottom
sample
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Uniboom survey until 24:00 in the lower part of the box until
CD1000. Continue with MVP and multibeam along various boxes.
THURSDAY
26/April/07

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07:30 - drop one person and get
on board other two for the
electro-optical part of the experiment (beach part); 10:10 deploy AOB22
on point G3; 11:00 - 10m depth in front of Castiglione della Pescaia,
station 1 for electro-optical measurements coordinated with the passage
of the satellites Ikonos and Quickbird; 12:45 -
deploying the rhib; Leonardo is in position F3 and rhib is
sailing to position E3; 14:00 - deploy sloop for multibeam survey
testing in very shallow water; 15:20 took bottom sample with TNO sample
grabber. Due to unforseen reasons the AOB22 deployed during this day
contained no valuable data since several hydrophones were not properly
acquired and the existing ones showed large noise interferences and
offsets.
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Castiglione
della Pescaia
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NURC's
boomer
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Night plan: uniboom near Castiglionne della Pescaia (point I1 to I3 and
H1 to H3) but in along the coast tracks. CTD casts over the box during
the rest of the night.
FRIDAY
27/April/07
11:00 - deploy AOB21 at point
G5; 11:20 - deploy AOB22 at point G4; points G4 and G5 are located
along line CD13000 approximately 3 and 4 km from location H1 of
Leonardo transmission; 12:15 - deploy RHIB; 12:30 - start electro
optical measurements near the beach and two more points off the coast
in coordination with satellite passes; recover AOBs: it appears that
AOB21 has stopped the acquisition twice during the day. It has been
remotely restarted once. |

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The
RHIB is approaching the Snellius
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AOB22
recovery cable tied under the buoy...
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Night work comprises X-star along or across uniboom tracks.
SATURDAY
28/April/2007

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09:30 - deploy AOB22 on point G6
slighly north from the PQ transect between J2 and K2; 09:45 - deploy
RHIB by location K1; 10:00 - transit to B point to make B to A
along the transect with X-star; 12:50 - end of X-Star run; 13:30 -
deployed AOB21 along the K2 - J2 transect (PQ line); 13:45 - doing
reflectivity measurements nearby AOB22; 14:30 - recover AOB22; 15:00 -
recover AOB21 and transit to Portoferraio; 17:30 - disembark Federico
Cernice in Piombino; 18:00 - disembark Piero and others in
Portoferraio; 21:30 - embark REMUS team from NLHO; 22:00 - leave
Portoferraio with MVP out.
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Repairing
the AOB22 GPS
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AOB22
at sea
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Night work: MVP and CTD around the box.
SUNDAY
29/April/2007
Castiglione della Pescaia area:
10:00 - deployed RHIB with Remus team; 10:30 deployed lauch for
acoustic measurements of Remus self noise; 11:30 taking bottom samples
nearby EF trasects; 12:15 doing reflectivity measurements nearby
Castiglione beach;
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getting
sparse array ready for deployment
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water
reflectivity measurements
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Night work: CTDs in the south eastern area of the box.
MONDAY
30/April/2007
Weather is covered, sea state 1/2, wind predictions are east
winds in the morning, decreasing by 2pm local and then turning south
and reinforcing for the afternoon. Showers during the day.
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08:00 - sloop left with REMUS
team to make very shallow water sidescan survey; 08:30 starting 6 MVPs
along the AB line (B to A); 09:30 transfering J.C. Legac from Snellius
to Leonardo nearby A point; 10:00 deploying AOB21 at ST12; 10:15
deploying AOB22 at ST20, Leonardo will be transmitting from ST2 so
AOB21 will be at 5 km range ST12 and AOB22 will be at ST20; Leonardo
will start be doing a CTD and then the acoustic rampup - full power
foreseen by 10:30. Queen's day cerimony took place at 11:45 while doing
MVP up and down the AB line; 11:30 - we are passing nearby ST20
and receiving nice acoustic signals from AOB22. Apparently the buoys
are slowly drifting towards NNE; 13:00 - sloop is on board with the
REMUS team near Castiglione della Pescaia; 13:15 going back to the buoy
area. Doing grabb samples along AB.
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Royal
Navy REMUS prior to deployment
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Last
AOB21 deployment along AB line
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TUESDAY
1/May/2007
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09:00 - deploying the RHIB
with the sparse array and the sloop with the REMUS team. Preparing run
over the E-F track with an upper slope REMUS exploration grid. Passive
inversion run with Snellius nearby RHIB and recover at 15:00; no
foreseen AOB deployment this day. AOBs are in the boxes to be stored
and left on board Snellius.
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WEDNESDAY
2/May/2007
08:00 disembarking from Snellius to pick the next ferry out from Elba
to Piombino and then to Milano.
Conclusions
A very fruitfull experiment where the nice weather and the
cooperation of the Snellius crew were the most important contributions.
A large amount of, what looks as very good, data was gathered by the
various teams on the 3/4 platforms involved. The work is now on the
scientific side to produce the most out of it.
Epilogue -
life is not so difficult on
board Snellius...

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man
over board...
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...Club
Med ?...
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Queen's
day
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Last
update: May 15, 2007