Makai Ex 2005

High Frequency initiative sea trial 

Kauai I. (Hawai), September 15 - October 2, 2005

HLS logo  UAL logo  NURC logo  NRL logo

UD logo     SPAWAR logo

SiPLAB participation is funded by CINTAL - University of Algarve under projects NUACE (POSI/CPS/47824/2002) and RADAR (POCTI/CTA/47719/2002) from the Portuguese Foundation for Science and Technology (FCT)


1. Ocean effects: surface wave effects on acoustic propagation; high-frequency tomography ot invert oceanographic features;
2. Sediment acoustics: validate ambient noise bottom imaging; obtain bottom inversion using ambient noise at high frequencies; use ambient noise in very shallow water; use airplane noise for bottom inversion; use communication signals for bottom inversion.
3. Vector Sensor array: usage for communications; source tracking; ambient noise;
4. Field calibration: usage of comm signals for determining field response;
5. Acoustic communications: teste MIMO communications; environmental effects on state of the art channel equalization both in single user and multi user mode; test a variety of communication modulations.

Teams aboard (15 - 27 Sep)

HLS: Mike Porter (PI), Martin Siderius, Paul Hursky and Katherine Kim (off Sep. 23)
UALG: Sergio Jesus, Antonio Silva and Fred Zabel
NURC: Thomas Folegot, Marco Lazzeri and Rod
NRL: Wen-Bin, Jeff, Mike and Walker
UDEL: Mohsen Badiey, Art Sundberg (off Sep.23), Jing Lo and
SPAWAR: Keyko MacDonald and Marc Gilchrist
WHOI: Jim Preisig (off Sep.23)
MPL: Heechun Song (off Sep. 23)

Sep 11 - arrival in Honolulu

Sep 12 - discover that equipment has arrived in Honolulu on Friday 9 through Continental Airlines; got customs cleared in the afternoon but no success when attempting to transfer it to UH Marine Center; involved DHX for delivery next day; start worrying about flotation devices from Urethane Tech.

Sep 13 - visited Kilo Moana (KM) (pic below);
got equipment at noon and flotation pack just after; loading it aboard ship (right pic); start looking for a way to pass antena and rotor cables into forward MET-LAB room.

loading equipment aboard KM

Sep 14
- preparing for departure; installing labs: wet - lab and forward lab. Installing antenas on top scientific mast and passing cables through dec to forward lab.

wet lab   
Wet lab

Making tests with new Li-Ion battery pack. Verifying status of equipment in the boxes; booting software and testing wireless communications;
met lab
 Met lab

departing from Honnolulu  

 Sep 15 -
departing Honolulu at 7:30 am;

Going directly W-NW to Kauai I, approximately 7 hour transit

Sep 16
- start deploying thermistor strings TC1 (UD); making XCTDs; deploy TC2 from NURC: cement anchor brooke apart on the deck and mooring got tangled underneath the starboard hull of the ship. Line was completely recovered at the end but two benthos subsurface floats were broken

SLIVA was deployed from port side for ambient noise measurements: it was found that low frequency (or ship) noise was saturating and that a highpass filter is required to get it out.


Sep 17
- deploying ACDS 1 at 98 m water depth. The surface unit went down as soon  as the cement anchor was released. The norwegian float also disapeared. At least 45 min passed between the moment when the surface unit was lost and the release was fired for surfacing. At that moment the large yellow subsurface float appeared to the surface but no surface unit was seen. The ship went way from the yellow sub surface buoy and it was lost.
The thoery is that there are at least 2 knots currents at this site and the 35 m of slack cable were not enough to maintain the surface unit afloat. When it went down the foam floats shrinked and the steel cables went loose, the floats escaped to the surface and the surface went down, probably flooded.
When the release was fired the yellow sub surface float was capable of bringing everything to the surface but then there was a wrong manouever from the ship for the recovery of the system.
ACDS systems

At noon we start searching for the waverider buoy, the two UD thermistor strings and the ADCP. All these were deployed without releaser and a buoy at the surface. None of them could be seen.
The actual currents were measeured at up to 1 m/s (2 knot) which would easily explain the problems encountered with the ACDS and the UD moorings.

At 17:00 TB1 was successfully deployed on station 4B. It was monitored to be up and transmitting a song.
At 19:00 a modem was deployed from the ship to shut off TB1 in order to save batteries but the cable got cut by one propeller and the modem and monitor hydrophone were lost. Until 02:00 am next day a solution was improvised to be able to communicate with TB1. That was successful.
SPAWAR testebed 1

Sep 18
- first AOB 2 deployment on a free drifting configuration, well North from all other equipment. The sea state was approximately 2 m waves with 30 knot winds.

Due to an unknown reason the RBR thermistor string did not start acquisition at startup, acquired 15 min of data later during the day and stoped.

See detailed explanation of AOB2 history, technical specs and objectives here.
AOB2 preparation before first deployment

During deployment the long surface float line got stuck in the radar reflector so the buoy was heavily listed.  KM stayed very close to the AOB2. Communications were perfect. Data was received in good conditions.

AOB2 was drifting along to the NE during 4 hours. TB1 was transmitting and signals were recieved aboard AOB2 and transfered to KM for inspection.
AOB2 first deployment Sep 18, 2005

18:00 - recovery was very difficult because strong cable was too short. At first recovery hook hold on scotch tape used to attach recovery line and floating cable. Scotch tape brook apart and AOB2 splashed into the water. Next hook up was difficult and AOB2 got stuck under starboard KM hull. Radar reflector, wireless antenna and RBR connector were lost during recovery (picture on the right).

20:00 - SLIVA deployment from KM.
AOB2 recovery

Searching for moorings

Sep 19 -
the weather clearly improved and it was possible to deploy the workboat for snorkling looking for the UD moorings. That was done during part of the morning, until 09:00.

No moorings could be found.

11:00 - AOB2 was again deployed from KM. Deployment went smooth. AOB2 was up and acquiring data. Lost sight of it since KM went to deploy TB2 at previous ACDS2 location (100 m isobath).

The AOB2 could not be found at the previous location and 1 hour was spent looking for it. For an unknown reason the wireless connection was broken. Fred could spot AOB2 from the bridge and it was safely recovered at 14:30. Data acquisition was working at all times, even without wireless comms.

17:30 - the AOB2 was redeployed attached to the ship with a 200 m long line. KM was heading south with wind while AOB2 was pushing NW due to currents which created a lot of tension on the surface buoy.
TB2 deployment
TB2 data

Problems were found on the data.

Spikes extending to the upper frequency band were
seen to corrupt the whole data set.

These spikes can be seen on the figure on the left where the signal transmissions obtained from TB2 are also recorded. LFM's, tones, M-seq and PSK transmissions can be clearly seen on this recording.

Sep 20 - this day was spent looking for solutions of the data acquisition problem on the AOB2. It looks that the problem is due to heating inside the buoy container, since problem seem to increase with time. A temperature recorder inside the container showed that temperature was increasing during data acquisition, up to 42 degrees (in the upper part of the bottle). Fans were placed and the temperature problem has diseapeared.

10:00 - TB1 was recovered and batteries replaced (sta 4B)
12:30 - UD tripod was deployed (sta 3A)
15:00 - TB1 was redeployed and turned on via modem link (sta 4B)
19:00 - Vector Sensor array was deployed from KM stern and recorded data during night.

Sep 21
- 07:30 recover UD tripod and data seems to be OK, although the first two hours were blank due to tripod hit on the deck (!?).

08:00 - shutting down testbeds and get ready for MIMO operation.
UD tripod

11:00 - deploy ACDS 1 on a free drifting (safe) configuration
12:30 - deploy MIMO array from KM stern at 50 m depth. Array extends for 20 m (50 to 70 m).
18:00 - decision to redeploy AOB2 on Sep 22.
20:00 - ACDS recovery was quite difficult and long due to multiple heavy vessels and floats to be brought on board.
21:00 - AOB2 Data acquisition problems found again on data. Up until 3 am next day and decision was made to postpone Sep 22 deployment.
ACDS in free drifting mode

AOB1 array adapted for AOB2

Sep 22
- The AOB2 stack was dismounted, remounted and retested. The peaks seem to have disapeared, instead we have got two dead phones. The cable of phone 1 is cut close to the hydrophone but also phone 2 was missing. The power supply on the surface buoy connector was found to have been damaged.

The UD tripod is back in business and being readied to be redeployed.

12:30 - SLIVA array was deployed suspended from the stern while the KM is in free drifting mode.

Sep 23 - Foreseen personnel drop off at Kauai at first light (6:30 am).
09:00 - getting to position again close to recover TB2.
10:00 - TB2 recover; tested if TB1 was up and transmitting; transmit OK.
11:30 - deployed AOB: signals checked and no transmission in the water.
AOB started a long drift to the north - NE, passed close by TS3 and got as much as 2.8 km away from KM. MIMO was deployed for testing.
13:30 - MIMO was recovered and approach to AOB;
14:30 - AOB recovered.
16:00 - getting ready to deploy TB2 after re-battery
18:00 - recover TB1; preparing for long tow of TB1 on NURC's tow frame.
19:30 - deploying Vector Sensor array on top of TB2
20:00 - doing a CTD
MIMO system

Sep 24 -
deploy AOB2 at 07:30
08:30 - recovering UD tripode.
11:30 - deploying TB2 from the ship and start towing. This day TB1 and TB2 swaped: TB1 got at TB2 usual location and TB2 got towed by KM. Long AOB2 8 hour drift towards NE. Got concernned about it running to shore. Got a nice piece of data both from TB1 and TB2. Source tow first passed close to AOB2 towards north than make it to west and draw a large box shaped pattern around the AOB2.
15:00 - recover TB2
15:45 recover AOB2.
17:00 - shutdown TB1
19:00 - deploy MIMO
21:00 - testing small LUBELL source together with VSA at ships stern, preparing for next day deployment.
AOB2 before deployment

Sep 25 -
Field Calibration : deploy AOB2 at 07:30.
08:00 - deploy RHIB boat for LUBELL source tow.
08:30 - deploying SLIVA from ship's stern (data acquisition with problems, using VSA recorder).
09:00 - start transmissions with LUBELL source from location 1.
10:00 - RHIB boat reached KM while transmitting
10:30 - RHIB boat started second run towards point 3, while continuing transmissions.
12:00 - end of LUBELL 916 transmissions; RHIB boat onboard.
13:00 (?) - start SPAWAR LUBELL source transmissions; long run along several tracks back
and forth along the AOB2 south drift.
14:00 - saw Mike Buckingham's airplane, chartered boat and flyby vertical array.
17:30 - stop LUBELL transmissions;
18:30 - recover AOB2 in partial dark after more than 11 hours of recording;

RHIB boat out for LUBELL source tow

dismounting AOB2 antennas

Sep 26 - MIMO testing with ACDS recording (free drifting configuration).
08:00 - ACDS is deployed.
08:45 - MIMO is  deployed but not transmitting yet.
09:20 - MIMO started transmitting and getting away from ACDS up to 2 km.
10:00 - dismounting AOB2 antennas from top mast.

Packing AOB2 equipment; dismounting top mast antennas and getting data recordings and backups done.

Sep 27 - disembarking personnel.
6:30 - getting off the boat using the RHIB boat off KM.

THE END of Makai Ex

the start of data analysis !!...

Last update : October 3,  2005