Orientation by AUV Bootcamp - Introduction and Day 1

I've been asked by my advisor, Dr. Art Trembanis, to manage a blog throughout the summer. My view is that a blog is a great sign of transparency in research, plus, I think my adventures this summer will be entertaining to follow. Hope you enjoy!

As a trial by fire, my first assignment for this summer's internship has been to survive a week of AUV bootcamp. The week's itinerary includes (complements of Val Schmidt):

1) Gavia AUV operations, familiarization, and data processing.

2) Acoustic Tracking Buoy operations with Tom Weber and Jon Hunt. The buoy's combine RTK GPS with acoustic modems and other ancillary sensors in order to track and talk to the AUV while it is deployed.

3) GeoAcoustics Software Training with Tom Hiller of GeoAcoustics (a Kongsberg Company). The focus is on processing the Gavia's GeoSwatch bottom mapping sonar data.

4) Fledermaus 7 demo with Erin Heffron.

The entire team is a collection of members from the University of Delaware's Coastal Sediments, Hydrodynamics, and Engineering Lab (CSHEL): Art Trembanis, Doug Miller, Adam Skarke, Nicole Raineault; the University of New Hampshire's Center for Coastal and Ocean Mapping (CCOM): Val Schmidt, Tom Weber, Kurt, Schwehr, Jon Hunt; Gavia AUV operation expert Alex Forrest from the University of British Columbia; Fledermaus representative Erin Heffron; GeoAoustics representative Tim Hiller; and an assortment of others that will and have dropped by, including CCOM Co-Director Larry Mayer. There will also be an unpaid (as of yet) intern from Colby College, via the University of Delaware's NSF funded REU program...

Day 1:

Muster at 7 am at the CCOM lab, meaning getting breakfast at 6:30 and wake up at 6. Who said this would be easy? But, once I rubbed the z’s out of my eyes I managed to get to breakfast and meet the Delaware research group – Art, Doug, Adam, and Nicole. We made our way to CCOM for introductions and loading of the gear.

Once we arrived at Mendum's Pond - our field site for the week - we prepared our gear.

Nicole inflates the Zodiak

The Gavia gets lowered from the dock into the water

Acoustic positioning buoys get wet

RTK station gets set up to provide a very precise GPS location as reference for the week.

Once the Gavia was placed in the water, it needed to be trimmed with weights as to have the proper buoyancy.

Here the Gavia sits trimmed.

The Gavia is then turned on and the INS is warmed up for 20 minutes. The INS is the Gavia's Inertial Navigation System. When the Gavia is on the surface, it uses GPS to locate itself. However, GPS does not work under water. The INS has accelerometers (like a Nintendo Wii remote) that spin and detect changes in directional movement. Therefore, the INS feels the movements of the Gavia while underwater and constantly updates its position, allowing it to navigate without being tethered.

Another instrument to be tested is the Pinger locator...

Here, Doug Miller is using a hydrophone to listen for a ping sent out by the Gavia. This is used to help locate the Gavia while it is underwater. It is somewhat of a backup system to locate the Gavia in case it does not return to where it is supposed to at the end of the mission.

As I've learned, the other forms of communication with the Gavia are through Wi-Fi with the command center computer and text messages through an Iridium satellite phone. These methods for communicating have their limitations: both are functional only at the surface; the Wi-Fi has a very limited range of transmission; and the Iridium has delays in delivering messages. Thus, the need for the pinger system. Also, a motivation for Tom Weber's Acoustic Buoys. The buoys are capable of tracking the Gavia's location underwater, as well as hopefully communicate messages for in-mission updates.

With the instruments warm, it was time to plan the first mission...

...from the beginning position...

...to the end...

Here, Alex and Val collect the GPS position for the end location of the Gavia's first mission.

The first mission ran very smoothly, and once recovered and brought back into Wi-Fi range, gave some great side-scan data!

The side-scan data was then converted to a kmz file and loaded into Google Earth. Very cool.

Two more missions were planned and run during the day.

The third mission gave us all a little excitement when the Gavia did not return home. However, using the buoy tracking system, and a GPS location message from the Iridium, the Gavia was recovered from its location beneath a log. The Gavia has a collision detection sonar that is directed in front of the nose, causing the Gavia to emergency-brake if there is an object in its path. It will then rise to the surface and try to continue its mission. A working thought is that the Gavia E-braked and then got stuck under the log.

But, no matter how it's put, 3 launches = 3 recoveries is a great start to the week!

The night ended with a great dinner at Val's house, where I had probably the best strawberry rhubarb pie of my life.

A beautiful day, great people, delicious dinner...is field work always like this? Sadly, everyone made sure to tell me it isn't.

Other things I learned from the day:

1) While planning the mission, it is important to select which sensors you want to use during the mission. If the study is not interested in certain data, it may be best to save the Gavia's power and not use extra instruments.

2) Data is not being collected around the turns of the Gavia. We are losing data in sometimes the most interesting spots.

3) A necessity when working with this type of equipment is proficiency and comfort with software. Geology uses some of the most high tec and computer intensive fieldwork.

4) Also, when doing research, it is very important to know all the inner workings of your equipment, as well as provide feedback to the manufacturers. For example, when the collision detection sonar was first implemented the sonar beam was aimed in too broad a path that the Gavia was performing E-brakes at times that it didn't need to. The researchers using the equipment then gave some suggestions and the beam was narrowed.

4) Gavia can travel at constant depth or follow the terrain (constant altitude).

Kurt Schwehr has an album of photos from the day located here:

http://vislab-ccom.unh.edu/~schwehr/gavia/20090601-mendums-pond/index.html