Marine Geoscience Data System
TN234 Dive Information
Clague, David
Investigator
MBARI
Platform
D. Allan B.
AUV
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Dive Information

Devices

Related Data Sets

Dive Information

Total Dive Count: 5
Events

20090507
Start
173.696° W 15.0725° S
2009-05-07T02:08:00
Locale
Lau-> WestMata
Volcano
Stop
2010-05-07T05:48:00
Nav Type
NotProvided
Details
The AUV aborted the mission during its spiral descent at 942 m depth due to an INS reset following the interruption of power. No mapping data were recorded.

20090508
Start
174.2655° W 15.4023° S
2009-05-08T00:49:00
Locale
Lau-> N-ELSC
SpreadingCenterSegment
Stop
2010-05-08T05:15:00
Nav Type
NotProvided
Details
The AUV aborted the mission during its spiral descent at 1090 m depth due to an INS reset following the interruption of power. No mapping data were recorded. The INS reset problem was successfully resolved following this mission by replacing the relevant power cabling.

20090509
Start
174.264° W 15.4013° S
2009-05-09T00:56:00
Locale
Lau-> N-ELSC
SpreadingCenterSegment
Stop
2009-05-09T20:30:00
Nav Type
NotProvided
Details
The third mission was a 75 percent success - the AUV performed about half the survey without any problems. Then, while running along a near-vertical slope, the DVL lost bottom lock immediately after getting an altitude value of 38 m, which was above the abort altitude but below the desired altitude. Because the AUV control software operates on the last good information, the vehicle went into a steady climb for 25 minutes until the altitude got reset. During this time, the INS was in free inertial mode, and the navigation accrued errors of several hundred meters. The rest of the survey was misplaced on the seafloor and much of the data was collected from altitudes either larger or smaller than desired. The AUV control software was subsequently modified to prevent a reoccurrence of this novel failure mode.

20090511
Start
173.476° W 15.1233° S
2009-05-11T00:40:00
Locale
Lau-> WestMata
Volcano
Stop
2009-05-11T19:25:00
Nav Type
NotProvided
Details
The fourth mission successfully covered the summit region of West Mata. The AUV did suffer several altitude aborts (when the vehicle gets too close to the bottom the propeller shuts off and it floats up until the altitude is acceptable), resulting in the survey covering less distance than planned. The altitude control settings were adjusted to reduce the likelihood of altitude aborts in the next mission.

20090512
Start
173.7603° W 15.1234° S
2009-05-12T01:57:00
Locale
Lau-> WestMata
Volcano
Stop
2009-05-12T21:20:00
Nav Type
NotProvided
Details
The fifth mission was a complete success.

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