Jaffe Laboratory for Underwater Imaging

We returned yesterday from the first deployment of the new MAZOOPS zooplankton sonar at sea. We were able to deploy the system several times per day, and collected nearly 100 GB of acoustic and image data from two different stations off the coast of San Diego.  Deployments of the MAZOOPS were combined with MOCNESS tows and the two modalities generally showed good agreement.

Below are two videos showing the deployment and recovery of the system at sea:

In total, the system was deployed eleven times during the four day cruise. Typically, the system was deployed running in autonomous mode during the day down to 250 meters, and running in tethered mode with real-time data during the night down to 100 meters. 

During the daytime, typical profiles showed that most of the acoustic scattering was down around 250 meters or deeper. These data were supported by images from the low-light-level camera on the MAZOOPS. Image data showed that copepods and euphaussiids were likely the most abundant animals, and these data were confirmed by the MOCNESS tows.

On two occasions, while idling at 30 meters depth, the system encountered very high concentrations of euphausiids which were seen in acoustic data as a dramatic increase in the number of echoes and also the amplitude of these echoes. Image data showed a proportional increase in the number of animals imaged. These small scale features are unlikely to be seen in MOCNESS data (due to its averaging of animal concentrations over much larger scales than the MAZOOPS.

Dr. Jules Jaffe was interviewed by "The Naked Scientists" concerning Robots of the Ocean - link to radio interview in top right corner.
Direct Link: Radio Interview

July 11, 2008 - After returning from the Acoustics 08 conference in Paris, we heard the great news that Paul Roberts won first prize in the student poster contest for his poster entitled "Application of multiple-angle acoustic scatter to remote fish classification." The poster investigates how certain key parameters in a multiple-angle system (such as array aperture and signal bandwidth) effect the ability of the system to classify fish of different size, shape, and species.

This week we are being featured on an internationally syndicated radio show: Pulse of the Planet. The audio describes our work in testing a new idea related to measuring the microbial environment and hence the viscosity of the ocean. If you would like to listen, please go to the following link and check out the archives from August 14, 15, and 20th and October 9th.
Webpage: http://www.pulseplanet.com
Direct Links: Testing (8/14), Revelation (8/15), Launch (8/20), Scatter (10/9).

August-September Cruise Results in Unique Data Set.  
The goal of our most recent cruise was to deploy our FIDO vehicle in various configurations to observe particle size spectra and also time varying scatter of light in the ocean.  Leaving from San Diego we over-nighted off Catalina (up and back) on the way to the Channel Islands. The cruise went extremely well.  We profiled with the FIDO - PHI configuration for 4 nights and then switched over to observe time varying scatter by suspending a small disk from FIDO with the laser incident on it from one direction and the camera imaging from the other.  We saw some amazing radial spokes of light emanating from the center of the scattered light patterns that we believe have never been seen before!!....What could they be from?  We are currently figuring out what we got, what to do with it and what it will tell us about oceanic micro structure and the propagation of light the ocean.  Stay tuned for more.