Broadkill Beach Frame Deployment

Photo journal of Nicole Raineault's study site, Broadkill Beach, and her instrument frame.

Here, Nicole is doing some final programming of her instruments. On the left, the red instrument is an Imagenex Rotary Beam Sonar for collecting images of the reef. On the right, the gray and black instrument is a Nortek instrument used for measuring water currents.

Learning to use the handheld GPS.

Doug and Adam watch as two field workers map GPS coordinates around the outside of the reef. The coordinates will be used to mark a path for the AUV.

Figuring out the last details for the deployment.

The frame placed in the surf

Beach profile down to the frame

We'll be back in a few weeks to remove the frame and then redeploy it on the beach side of the reef.

Arriving in Delaware

Monday, June 8.

Wake up call at 5:30 am. Today was finally the day to complete my drive to Lewes. Not that the other days haven’t been an adventure.

After my seminar, I then drove to Annapolis to pick up some parts for Nicole's Frame. Really beautiful city.

Lewes Beach

Located just about 1.5 miles from Daiber housing and on the Bay side of the water is Lewes Beach. I've been trying to come to the beach each day, even if it's just for a few moments. I have a perfect streak of 2 days so far...

Day 5

Photo Journal of Day 5

Today, we did some creative shore launches with the Gavia...

I manned the boat crew again...

All smiles all day...couldn't have asked for a better field day.

Nicole and Val relaxed...

...as well as Alex...

...and so did the Gavia.

Doug took one last trip into the setting sun...

Then we packed up the Gavia

and then the day was done...

And away we flew.

Day 4

Day 4

Today was another full day of classroom sessions. We learned more about the vehicles' settings and filtering of data, including the need to calculate for tides and sound velocity. Sound velocity can change temporally and spatially if you go past an outflow, estuary, river, eddy, rip tide. There must also be calculations for heave (and do it often) because if the vehicle is moving up and down, the position of the sound is off and sonar does not make an accurate image.

We then ran some tests on the Gavia in the CCOM testing tanks

Here, Tom instructs the group on some aspects of the GeoSwath program...
...and this is an image of the test tank as seen by the Geoswath sonar.

The Gavia seen through a port hole in the tank

Day 3

Wednesday.

Back to the field for another day of AUV ops. Today, we also had some fun with an ROV (Remotely Operated Vehicle), the VideoRay.

Here, we do our part as environmentalists and retrieve a Cola can from the depths.

Doug and I made up the "Boat Team" today, and were responsible for launches and recoveries of the AUV.

We also tested the ping locator by taking the spare and bringing it to different distances from the dock. We found it was very directional.

Other things I discussed today:

1)Acoustics. Especially with Tom Weber. There is a Sound Velocity Sensor on the Gavia which takes readings of the water column to calculate the water's sound velocity. The velocity is taken into account when the sonar data is processed. Temperature, salinity, and some other factors change the speed of the sound in the water, so thermoclines are important features to map. Also, the Navy knows a lot about these features because they can use them to hide submarines. The layer can either prevent sonar from detecting the sub, or from the sub sending out its own sound signals. Another basic thing I learned is that we use sound and sonar because electromagnetic light and radio waves will not penetrate into water. What Tom has done with his buoys are to use a program like MatLab to make and translate electric pulses into an acoustic signal using an acoustic modem. These acoustic pulses can be used to communicate with the Gavia.

At the end of the day, we held a classroom session with Alex Forrest.

Things we learned in the classroom:

- Pre-mission setup (last minute checks)

- post-flight checks

- data retrieval

- analysis of scientific payload data

- mission planning – toolbar to choose things like lawnmower pattern. also make a waypoint (start and end) or line.

- power status of the sensors – some take a short time to power up while others take a longer time (3 minutes). - Must give enough time to boot up and then check that they are turned on.

- upon return of the AUV – is there data? go into the file folders. Download log files and check navigator/ mission manager/ captain files.

There are only 14 max Gavia units…this is an elite crowd that I’m in.

AUV Ops - Day 2

Day 2

Today we had a full day of classroom sessions with Tom Hiller from GeoAcoustics to learn GeoSwath+.

Of course, at one part of the day, the intern was called for a DD run.

Things I learned from Tom:

1) In Geoswath processing the original Raw Data File must have filters put on to limit the noise.

2) Beneath the AUV, the number of data points is low, so the quality is not very high. Overlapping the path of multiple missions will add more data points so that the quality increases. .

3) I was talking to Nicole and Doug about their project on hard bottom communities in Delaware Bay, which we will work on when we return. The hard bottom communities are tube worms that use sediment in the water to create the reef. Although the worms are found all along the east coast, they only make the reefs near Delaware. Nicole is trying to find if hydrodynamics of the sediment transport is the cause for the hard bottom community’s distribution.

We had another great dinner, this time at Newicks Seafood. It was an interesting feeling for me, because I remembered when I was doing my Marine Biology course at St. Paul's that we came to Newicks to sample the water quality. I was sure then that I'd be in the field of Marine Sciences, and am starting to get myself back into it.

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