About this Cruise

This month-long cruise aboard the NOAA Ship Oscar Elton Sette brings together six diverse teams to survey fish populations using non-catch methods. Traditionally, fish populations have been assessed by catching fish, visiting fish markets and interviewing fishermen. Chief Scientist Scott Ferguson hopes to support Guam and the CNMI in monitoring their natural resources using non-extractive methods. The ship will also use multibeam sonar to map areas that are important fishery resources hopefully to include Galvez Bank, offshore slopes near Rota, and the banks of Farallon de Medinilla.

The survey methods include BotCams and BRUVs, two systems that put baited cameras on the bottom, and a TOAD which is a camera towed near the seafloor . An Autonomous Underwater Vehicle will travel on its own via computer programming and bring back photographs and video. Additionally, acoustic methods will be used to survey fish in the water column.

This expedition brings together scientists from NOAA’s Pacific Islands Fisheries Science Center and Northwest Fisheries Science Center, as well as the University of Hawaii’s Joint Institute for Marine and Atmospheric Research, the University of Guam Marine Lab, and Woods Hole Oceanographic Institution.







Sunday, February 28, 2010

Old Dog, New Trick

What is the most exciting, most awesome, most unusual event of the expedition? These are the most common questions I have received from students following the blog. The whole trip has been exciting and awesome. It’s also been unusual as I don’t normally spend a lot of time at sea.

Unexpectedly for me, on February 23rd came the most exciting, most awesome and most unusual event of this trip. By then, I was familiar with the Autonomous Underwater Vehicle. I had read about it, talked about it, written about it and taken dozens of pictures. What I didn’t know was that Chris (see Meet the Science Team) was working to teach the AUV a new trick. AUVs run a preprogrammed route for about 4 hours and then return to the surface. It’s not until the AUV is back in its cradle on deck that the cameras can be retrieved. Only then can the photos be seen. Chris spent the trip devising a method whereby the AUV can send pictures to the ship while still underwater.

Left: Seven miles of cabel used by the Remotely Operated Vehicle Jason II.

Keep in mind that the AUV is not attached to the ship. Remotely Operated Vehicles (ROVs) are attached to the ship via cables and can send pictures and receive instructions from the control room on the ship. On the AUV’s last dive, Chris’s program worked―underwater pictures on his computer. He got 13 photos at about 20 minutes each. The information is sent to the computer in small bits that must be assembled. HE DID IT! I wanted to break out the champagne in celebration, but there is none onboard so we had to settle for enthusiastic applause. I still get chicken skin (goose bumps) just thinking about the magnitude of his success.

Right: AUV, no cables.

In the following paragraph, Chris talks about AUVs and communication.

"Wirelessly communicating with Autonomous Underwater Vehicles (AUVs) is very difficult―the type of wireless communications that we rely on in our day-to-day lives does not work underwater. Most wireless systems, like WiFi or mobile phones, rely upon high frequency electromagnetic waves―millions or billions of cycles per second. Underwater, high frequency signals are attenuated, or blocked, over short distances. That is part of why when you are snorkeling or SCUBA diving everything looks blue―the higher frequency red light has been blocked out. To communicate with SeaBED AUVs, we rely upon sound waves, which use only around 12 thousand cycles per second. Echoes, other noise, and a number of other challenges presented by the ocean result in us having a very slow connection to the robot. Also, like using a walkie talkie, only one person can be talking at a time. If we are sending commands to the robot, it can't be sending us information. Finally, sound travels slowly through the water, so it takes time for the message to even get to the boat (this is called latency). That all means we have to heavily compress images so that they are very small on disk before we transmit them, and we don't get all the pieces in the right order. Putting together the image ends up being like putting together a puzzle―you have to make sure you have all the pieces, and then put them together in the right order. The compression means that the images look pretty rough, but they still give us an idea of what the robot is doing, and an early glimpse at the seafloor. For the rest, you have to wait until it comes back up! SeaBED AUVs can take over a thousand images every hour! "

OK, me again. Chris will continue working on this project. He wants to make it easier and faster. With this new trick, the scientists will know, while the AUV is still below, that all systems are working and the AUV is taking quality photos.

11 comments:

Shark Feet said...

wow ms. that seems a lot of work for some pictures your eventually going to get. so how long does it usually take to put together one picture and how many pieces do you guys get per pic.?
Jhorge Gonzales-1

Really Jhorge! So much work and we only know about a small part of it. Chris worked long and hard before this trip started to make his program work. He then put in more long hours on the ship before he finally received a picture. I know it took 20 minutes to get one assembled picture from the AUV to the computer screen on the ship. I don’t know how many pieces that involved and I can’t ask Chris because he got off the ship in Saipan.

Shark Feet said...

Hi Ms. T!
It's good to know you're having a great time. I found the AUV's to be very exciting. I wish i was there to experience it with you.
Anyways, I was just wondering what's the main difference between a ROV and AUV besides the fact that the ROV is attached to the ship? Don't they both take the same type of pictures?
Maria-5

Hi Maria,
Both the ROV and the AUV can take video and still pictures. Generally, we must wait for the AUV to return to the ship to see the pictures (new technology is being developed to change that as you know by reading about Chris’s work). The video and still pictures taken by the ROV are seen in real time in the control room on the ship. This is one advantage of a cable. Also the ROV has robotic arms that can pick up samples from the seafloor, catch marine life (that doesn’t swim too fast) and place experimental equipment on the bottom. It can do all of this because the driver can see exactly what’s happening by way of the video feed.

Shark Feet said...

Hi Ms.Tatreau
Hope you're having fun!!!
What was the depth of the AUV in which you guys were able to receive the images?
Ryan-3

Hi Ryan,
The AUV was traveling down a slope at the time the pictures were successfully transmitted to the ship. It got pictures from depths ranging from 100 to 300 meters (as deep as 950 feet).

Shark Feet said...

hey Ms tatreau! kris here...again. i have a question, what is your heaviest equipment that you guys carry around? im curious to also know how you guys maintain your equipment....for example....do you always have to clean the camera lenses??

Hi Kris Again,
The heaviest? I don’t know. Let me go outside and look at the crane. OK, the crane says, “Maximum load 6000 pounds.” However, I talked to the crane operator who told me the crane lifted 19,000 pounds during a test with the boom retracted. The crane lifts the cable spool at 9000 pounds. The boom can extend to 46 feet and that’s when it has a limit of 6000 pounds. Anything too heavy for the ship’s crane can be moved when the ship is at the dock using a land crane.

Shark Feet said...

Wow, very nice trick and discovery. It's nice to have the feeling of excitement to look at the pictures on the computer while the AUV is still underwater. Great information on the topic. Good luck on the project and wishing for more success.
Ritzmar-5

Hi Ritz,
You are my most faithful follower. I’m glad you read the information that Chris wrote on why it’s difficult to send pictures wirelessly through the water. I would have had a hard time explaining that.

Shark Feet said...

Hi Kris Again,
In answer to your second question:
It’s a constant struggle to keep the equipment clean and in working condition. Salt water is hard on everything. The ship’s crew is always working to keep the rust under control. The ship’s electronics and the science equipment are cleaned with regularity. Equipment that doesn’t go underwater is still covered with salt spray and needs daily attention.

Shark Feet said...

Hello There, KAYLA HERE!
i was just wondering
they said on the new that we have a tsunami warning
i was just wondering if you saw a change in the water. And while I was reading this blog i saw a lot of things you were telling us like the wire and all that. Glad to hear your doing will

Hi Kayla,
We were at the dock in Saipan when we heard about the earthquake in Chile. We were scheduled to sail just an hour before the predicted wave would have reached shore. We moved our departure time up a bit but then the tsunami warning was cancelled. Ships at sea do not notice tsunamis. It isn’t until the energy nears shore that the water builds up in shallow water and creates giant waves.

Shark Feet said...

Hey Ms. Tatreau!
You made me lol when you said that your colleague, Chris, had to settle for "enthusiastic applause." I was wondering, though, why it is such an achievement to be able to take pictures at a rate of 20 minutes for each photo? I realize that, through his explanation, it is really difficult to send those pictures wirelessly. On average, how many pictures can AUV take for an hour? And why don't you have champagne on board?
Odessa S-3

Hi Odessa,
I know it doesn’t sound like a big deal when it takes 20 minutes to see one picture. In this day of digital cameras, we have come to expect instant pictures, but getting the information to travel through air is very different from getting it to travel through water. The AUV takes 2 pictures every 5 seconds (you can do the math). It has two cameras that take pictures at the same time―one faces down to see the topography and the other faces forward so fish can be identified. The AUV cameras can be adjusted to take more or less pictures. No champagne because this is a NOAA ship. NOAA is a federal organization with strict rules. The rules include no alcohol, no drugs and no sex. That makes me laugh. How can they monitor sex?

Shark Feet said...

Hey Ms. Tatreau!
Thank God that tsunami didn't hit us! (: It's my first time blogging you. I can tell you have a lot on your hands! Must be tiring. Anyway, now that you are in Farallon de Mendinilla, you have no AUV, BotCam and BRUV teams how are you still collecting data? Are there other types of technology on the boat? Be safe!
Shawnese-5

Hi Shawnese,
I’m glad you decided to write. We were all happy the tsunami didn’t materialize. The camera teams are gone, but we are using the multibeam sonar to gather data to make maps of the seafloor around Farallon de Mendinilla. The ship is loaded with technologically sophisticated equipment. The mutibeam sonar is in the water sending information to the computers on the ship―there must be a dozen computers just for this operation and a couple of “magic” boxes (they seem like magic to me). Look at the pictures I posted under the title BRIDGES and you will see just a very small portion on the technical equipment on the ship. Be safe―that’s the ship’s slogan. Have fun―that’s mine.

Shark Feet said...

Hey Ms. Tatreau,
Wow, That AUV trick really is amazing. I would never have guessed that something wireless would work well underwater. Now that Chris figured it out, do you know if he plans on testing it on a new project anytime soon?
Angel 5

Hi Angelfish,
Chris will continue to work on this project. He is a graduate student at Wood’s Hole Oceanographic Institute in Massachusetts working on his doctorate. He hopes to make the wireless transmission of data through water faster and more efficient. Everyone who uses the AUVs hopes he is successful.

Shark Feet said...

Hi ms. Tatreau!!
It's Cayla! :) How did Chris teach the AUV to take the pictures underwater? Or how did it adapt to it? Also, Why must the pictures be in small pieces? Is there any way to have the AUV send the pieces in larger forms?

Hi Cayla,
If I knew the answer to that question I would be getting my doctorate in technology at the Woods Hole Oceanographic Institute. The pictures must travel in small pieces because wireless transmission through water is much more difficult than it is through air. In air, wireless signals are sent via high frequency electromagnetic waves. These don’t travel through water. In water, wireless communication must use sound waves which travel much more slowly. That is the simple explanation―there are many more complicating factors. Chris will continue his work in hopes of making the wireless connection faster and more efficient.