From UNH's 2013-2014 CCOM/JHC Seminar Series: Lieutenant Commander Samuel Greenaway, Executive Officer of the Ferdinand R. Hassler, presents, "NOAA Ship Ferdinand R. Hassler - Lessons Learned from the First Years of Survey Operations." This talk was recorded on April 4, 2014 at UNH's Jere A. Chase Ocean Engineering Laboratory.
This talk will present the Ferdinand R. Hassler, NOAA's newest hydrographic survey ship. At 125' in length and 900 tons, Hassler is a SWATH (twin hull, small water plane) vessel and presents new challenges and opportunities in conducting survey operations. Her primary survey instruments are two Reson 7125 shallow water multibeam systems and one Reson 7111, and two independent POS-MV position and attitude systems. The implementation of the frequency modulated (FM) dual-head 7125 is discussed as well as challenges with vertical control in a relatively unstable craft. With a small crew and limited berthing for visiting scientists, continuous 24-hour survey operations are a challenge with traditional approaches; new techniques of minimally monitored acquisition and remotely processing data are being explored. Hassler will soon integrate a 25' survey launch into her operations and continue evaluation work with a EM3002 equipped Remus 600 AUV. Finally, current areas of collaboration between Hassler and CCOM are presented as well as some discussion of potentially fruitful areas of future work
From UNH's 2013-2014 CCOM/JHC Seminar Series, Chris Roman, an Associate Professor at the University of Rhode Island's Graduate School of Oceanography, presents, "Hybrid Optical and Acoustic Sea Floor Mapping, and Some Other Fun Projects." This talk was recorded on March 28, 2014 at UNH's Jere A. Chase Ocean Engineering Laboratory.
This talk will present a method for creating hybrid optical and acoustic sea floor reconstructions at centimeter scale grid resolutions with robotic vehicles. Multibeam sonar and stereo vision are two common sensing modalities with complementary strengths that are well suited for data fusion. We have recently developed an automated two stage pipeline to create such maps. The steps can be broken down as navigation refinement and map construction. During navigation refinement a graph-based optimization algorithm is used to align 3D point clouds created with both the multibeam sonar and stereo cameras. In the mapping step, grid cells in the map are selectively populated by choosing data points from each sensor in an automated manner. The selection process is designed to pick points that preserve the best characteristics of each sensor and honor some specific map quality criteria to reduce outliers and ghosting. The final hybrid map retains the strengths of both sensors and shows improvement over the single modality maps and a naively assembled multi-modal map where all the data points are included and averaged. Results will be presented from marine geological and archaeological applications using a 1350 kHz BlueView multibeam sonar and 1.3 megapixel digital still cameras.
The other fun projects portion of the talk will present updates on a few other activities in the lab. These include detecting sea floor venting using a structured light laser imaging, real-time visual odometry for a drifting Lagrangian camera and test results from new vehicle for high resolution water column profiling
From UNH's 2013-2014 CCOM/JHC Seminar Series: Dylan Mikesell, an NSF Postdoctoral Fellow in MIT's Earth Resources Laboratory, presents, "An Introduction to Seismic Interferometry and Imaging with Seismic Noise." This talk was recorded on March 21, 2014 in UNH's Jere A. Chase Ocean Engineering Laboratory.
Using ambient seismic noise for imaging subsurface structure dates back to the development of the spatial autocorrelation (SPAC) method in the 1950s. However, not until recently have numerical and laboratory experiments shown how crosscorrelation of noise recorded at two points provides an actual estimate of the impulse response between these points. This correlation technique has been termed Seismic Interferometry (SI) in the active-source seismology community. In this talk we will investigate how the crosscorrelation of seismic records yields the impulse response. Both active sources and ambient-noise sources will be discussed. Furthermore, I will discuss the links between the SPAC and SI methods, demonstrate how they work, and show examples of imaging and monitoring using seismic noise correlations.
From the UNH CCOM-JHC 2013-2014 Seminar Series: UNH research professor Ray Grizzle presents, "25+ Years of Seafloor Mapping for Ecological Purposes." This talk was recorded on Friday, November 15, 2013 at UNH's Jere A. Chase Ocean Engineering Laboratory.
This presentation will be aimed at graduate students. I will briefly describe several studies I have been involved with over the years that have centered on mapping the seafloor to discern ecological processes, concluding each with questions that are still unanswered. Topics that will be covered include: the ecology of oyster reefs in Florida, how a fishing closure affected seafloor habitats in the Gulf of Maine, mapping methods and restoration of oyster reefs in New Hampshire, and mangrove and coral habitats in the United Arab Emirates.
From the UNH 2013-2014 CCOM/JHC's Seminar Series: Nicole A. Raineault, Ph.D., Director of Science Operations for Ocean Exploration Trust, presents, "Deep-Sea Exploration with the E/V Nautilus: Program Overview, Highlights, and Opportunities." This talk was recorded on February 28, 2014 at UNH's Jere A. Chase Ocean Engineering Lab.
The mission of the Ocean Exploration Trust is to explore previously unexplored or under-explored areas of the ocean to make new discoveries in the deep sea. To further this goal we work with scientists and engineers to develop cutting edge technologies that push the boundaries of technology and communications. An important aspect of our mission is to share our exploration with people around the world via telepresence. Ship-to-shore satellite communications and streaming of the remotely operated vehicle video and seafloor mapping via the web not only engages the general public, but also allows an extended science team to take part in our expeditions from shore. This presentation will provide an introduction to the Nautilus Exploration Program, highlights from past seasons, and a preview of the upcoming season. It will also include information on how students, faculty, and others can become involved.