Blue Planet - BP'07 sea trial

21 April - 2 May 2007, South Elba, Italy.

Logo NLHO Logo TNOULB logo NURC logo UAL logo

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:
  1. test low - frequency tomography and geoacoustic inversion with a network of light acoustic-oceanographic buoys (AOBs);
  2. acquire acoustic data to allow testing at the sea an integrated system of acoustic tomography for “Rapid Environmental Assessment (REA)”;
  3. 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

HMS Snellius Snellius Sloop RHIB from Snellius
Hr Ms Snellius (NLHO-Dutch Navy)
Snellius Launch
RHIB from Snellius
RV Leonardo

NRV Leonardo (NURC)

3. Means to be employed a board the various platforms

3. Test area:
MREA/BP 07 work 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
monitoring the AOB with a PDA monitoring the AOB with a PDA 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.

1. the AOB is at sea and is beaing monitored with the PDA 2. perfect deployment of the AOB from Snellius.

During night time Snellius was doing MVP and multibeam sonar since TNO, CTD had problems.

MONDAY 23/April/2007
AOB22 - h1
AOB22 - Hyd 10
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.

AOB22 - hyd1, clear multipath and multitones
AOB22 - hyd10, inverted image of low freq chirp;

During night time Snellius was doing uniboom along pre determined track on the upper part of the box.

TUESDAY 24/April/07
deploying AOB21
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.
BP07 working area
Deploying the AOB21

CTD survey during the night and multibeam.

WEDNESDAY 25/April/07
Deploying TNO's bottom sample graber Bottom sample
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).
Deploying TNO's bottom sample graber Bottom sample

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
Castiglione della Piscaia
NURC boomer 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.
Castiglione della Pescaia
NURC's boomer

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. The RHIB is approaching Snellius
AOB22 recovery from RHIB

The RHIB is approaching the Snellius
AOB22 recovery cable tied under the buoy...

Night work comprises X-star along or across uniboom tracks.

SATURDAY 28/April/2007

Repairing the AOB22 GPS
AOB22 at sea
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.
Repairing the AOB22 GPS
AOB22 at sea

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;
getting sparse array ready for deployment
water reflectivity apparatus

getting sparse array ready for deployment
water reflectivity measurements

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.

REMUS AOB21 last deployment 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.
Royal Navy REMUS prior to deployment
Last AOB21 deployment along AB line

TUESDAY 1/May/2007

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.

WEDNESDAY 2/May/2007

08:00 disembarking from Snellius to pick the next ferry out from Elba to Piombino and then to Milano.


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...

man over board
cruise in the Med
Queen's day

man over board...
...Club Med ?...
Queen's day

Last update: May 15, 2007