ARA Deploys Sonardyne USBL System in Port Survey
ARA Inc. (Sykesville, Maryland) has completed a
subsurface survey of Terminal 91 in the Port of Seattle, in which it
deployed its ROV ROUMRS and Sonardyne International Ltd.'s (Yateley,
England) Scout USBL acoustic positioning system, Sonardyne said last
Commissioned following the discovery of World War II munitions on the
seafloor under the cruise ship facility at Pier 91 within the terminal,
ARA’s operation was to identify and clear any magnetic anomalies that
could potentially warrant further investigation. The survey was
completed in March.
Scout USBL is designed for tracking divers, ROVs and towfish in waters
up to 1,000 meters. It calculates the position of a subsea target by
measuring its range and bearing from a vessel-mounted transceiver to an
acoustic transponder fitted to the target.
To undertake the survey, ARA mobilized its ROV ROUMRS, which was fitted
with a Sonardyne WSM 6 transponder. A Scout transceiver was deployed
from the side of the dock on a simple pole arrangement. Positioning
data from Scout was fed to the accompanying Sonardyne ViewPoint
"Although commonly used by the offshore survey and ocean scientific
industries, Scout is equally at home tracking a diver or target in just
a few meters of water so we were confident that it was the right
solution for ARA to use on this unusual project," said Ralph Gall,
technical sales manager at Sonardyne in Houston.
Caption: Engineers prepare the ROUMRS ROV,
equipped with a WSM 6 transponder, ready for deployment.
Source: Sonardyne International Ltd. press release
Sonar Could Aid Detection
In Cluttered Environments
the University of Southampton that examines how dolphins might
process their sonar signals could provide a new system for man-made
sonar to detect targets in bubbly water, such as sea mines.
The researchers used echolocation pulses of a type that dolphins emit,
but processed them using nonlinear mathematics instead of the standard
way of processing sonar returns. This Biased Pulse Summation Sonar
(BiaPSS) reduced the effect of clutter by relying on the variation in
click amplitude, such as that which occurs when a dolphin emits a
sequence of clicks. The study was published last week in Proceedings
of the Royal Society A.
BiaPSS was shown to be effective in distinguishing targets, such as sea
mines, from the clutter generated by bubbles in the sonar's field of
view, according to the study. The tests used linear frequency-modulated
pulses to detect a solid steel sphere that measured 0.12 meters in
When hunting prey, dolphins have been observed to blow "bubble nets"
around schools of fish, which force the fish to cluster together,
making them easier for the dolphins to pick off. However, such bubble
nets would confound sonar systems because the strong scattering by the
bubbles generates clutter in the sonar image, which cannot be
distinguished from the true target.
an engineering perspective, taking a dolphin's sonar and characterizing
is not superior to the best existing sonar systems. In blowing bubble nets,
dolphins are either blinding their echolocation
sense when hunting, or they have a facility absent in man-made sonar.
The study examined whether there is a way by which dolphins might
process their sonar signals to distinguish between targets and clutter
in bubbly water.
"We know that dolphins emit sequences of clicks and the amplitude of
each click can vary from one to the next, so that not all the clicks
are the same loudness. We asked, what if this variation in amplitude
was not coincidental, but instead was key to distinguishing fish from
bubbles," said Tim Leighton, lead author of the study and professor at
the university. "The variation in amplitude of these clicks is the key:
it produces changes in the echoes which can identify the target (fish)
in the bubble net, where man-made sonar does not work."
The findings do not conclusively prove that dolphins use nonlinear
processing, but show that man-made sonar could differentiate between
targets and bubble clutter using dolphin-like sonar pulses, Leighton
Professor Leighton added, "There are still questions to answer. For one
thing, dolphins would have to use a frequency, when they enter bubbly
water, which is sufficiently low that they can hear up to frequencies
twice as high in pitch. Until measurements are taken of wild dolphin
sonar as they hunt in bubbly water, these questions will remain
unanswered. What we have shown is that it is not impossible to
distinguish targets in bubbly water using the same sort of pulses that
The authors previously proposed a form of sonar signal, TWIPS, or Twin
Inverted Pulse Sonar, which could work in bubble clouds, consisting of
pairs of pulses that were identical except that one was inverted with
respect to the other. While TWIPS pulses were successful, there was no
conclusive evidence that the types of pulses devised for that study are
used by any type of dolphin.
Caption: Dolphins in the Atlantic. (Credit:
Source: University of Southampton press release
Launches Portable Acoustic Deck Box
Wareham, Massachusetts) has designed a new portable acoustic deck box.
The Portable Acoustic Command System (PACS) can be used to obtain
status information, enable, disable, range-to and release EdgeTech’s
low-frequency or medium-frequency acoustic releases and transponders,
the company said last week.
Capable of working with all EdgeTech, ORE Offshore and EG&G Marine
Instruments acoustic releases, PACS works with acoustic frequencies
from 9 to 25 kilohertz. The splash-proof unit operates on internal
lithium ion rechargeable batteries and has a backlit screen.
Caption: The Portable Acoustic Command System.
Source: EdgeTech press release
Hydema Completes Acceptance Tests
For ARRV, Receives WHOI Winch Contract
U.S. (Seattle, Washington) deck machinery for the RV Sikuliaq,
or Alaskan Regional
Research Vessel (ARRV), successfully completed factory acceptance tests
in Seattle. The company also announced last week that it was selected
by the Woods Hole Oceanographic Institution (WHOI) to supply an
electric ROV winch.
Other than winches, the tests for the ARRV deck machinery included the
load-handing system, which was tested in an upside-down configuration.
All major components have been delivered to Marinette Marine Corp.
(Marinette, Wisconsin) since the test, and remaining deliverables will
be completed soon. The remaining components from Rapp are two sheaves
and a display.
A University-National Oceanographic Laboratory System delegation and
representatives of Marinette Marine shipyard and the U.S. Navy's
Office of the Chief of Naval Operations witnessed the tests.
The ARRV should launch in October, Rapp said.
The company expects to deliver an electric ROV winch to WHOI in
February 2013. It will accommodate 7,350 meters of 0.681
electromechanical cable, or 7,500 meters of 9/16-inch cable.
The winch-powering scheme has three electric motors mounted on the
gearbox; management is through variable-frequency drives. Rapp’s
Pentagon Research winch control system will provide controls for the
active heave compensation. The system could see heavy usage at
deployments of up to 7,000 meters of cable, Rapp said.
Caption: A rendering of the Alaska Region
Research Vessel (Credit: The Glosten Associates Inc.)
Source: Rapp Hydema U.S.
Completes Red Sea Satellite-Based
Bathymetric Mapping Project
in 10 Days
Dhabi, United Arab Emirates) has completed a 200-square-kilometer
bathymetric mapping project along the Red Sea coastline in 10 days,
deriving the bathymetric data from DigitalGlobe (Arlington, Virginia)
WorldView-2 high-resolution, eight-band satellite imagery.
The project could have taken six to eight months if the data had
been collected by boat due to required government permits and
shallow-water navigation obstacles, Proteus said.
In the Red Sea, the satellite bathymetry process successfully extracted
seafloor elevation measurements to depths of 20 meters with a 4-meter
point density at distances up to 5 kilometers off the Saudi
The project used a bathymetric and seafloor mapping method that Proteus developed in
partnership with EOMAP GmbH & Co.KG (Gilching, Germany). The
bathymetric data supported an environmental assessment being
conducted by Sogreah (Lyon, France) in preparation for construction of
a new power plant south of Jeddah, Saudi Arabia.
Source: Proteus press release
Could Provide 10 Percent
Of Australia's Electricity, CSIRO Finds
energy could play a significant role in Australia's energy sources,
provided there is a price on carbon and the specific technology remains
within appropriate capital and operating cost thresholds, according to
a report published on Wednesday by the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
Ocean renewable energy could supply up to 10 percent of Australia’s
electricity by 2050. Compared to wave energy devices, the prospects for
large-scale deployment of tidal and ocean energy devices and systems
are less likely to penetrate the market before 2050, the report found.
Modeling used in the report returned the unexpected result that under
all scenarios investigated, tidal and ocean flow energy was not
considered competitive in Australia to 2050.
Australia's wave energy resources are concentrated along the country's
southern coastline. For example, the total wave energy crossing the
25-meter-depth isobath between Geraldton and the southern tip of
Tasmania is more than 1,300 terawatt-hours per year, about five times
the country’s total energy requirements. Other factors such as the
economics of energy extraction, transmission, environment and social
impacts will determine its future exploitation.
The east coast also provides a consistent, albeit not as large,
contribution. Tidal energy is most abundant in the Kimberley region in
Western Australia and Banks Strait off Tasmania; ocean currents off the
east coast of Australia; and ocean thermal energy off the coast of far
north Queensland. The report estimates 8 terawatt-hours per year for
a King Sound (Kimberley, Western Australia) barrage scheme and 0.13
terawatt-hours per year at most for a Banks Strait tidal
stream project. Additional work needs to be done to better quantify the
available extractable power from tidal flows.
Nontidal ocean current energy was found to be the least
technically and economically viable. However, the potential is large
enough—about 44 terawatt-hours per year—to attract commercial
Given the current activity and the outputs of the modeling showing
that ocean renewable energy could be a significant contributor to
Australia's future energy supply, the study recommends CSIRO commence a
structured approach to the development of a renewable energy program.
The study was carried out by the Wealth from Oceans and Energy
Transformed flagship programs. The assessment was a first for ocean
renewable energy in Australia, CSIRO said.
The full report is available here.
Caption: Australia's coast line in the Southern
Ocean has the best wave energy resources. Particular areas to note are the
west coast of Tasmania, the southern ocean in Victoria and southwest
Source: CSIRO press release
CARIS Launches Open-Source API
For Making Custom Web Maps
(Fredericton, Canada) released last week its first open-source API
API, allows users to create, embed and display custom Web maps on their
The API was created to extend CARIS Spatial Fusion Enterprise and
includes tools for navigation, measurement and download, as well as
providing a means for developers to create custom tools and extensions.
OSCAR-js extends the OpenLayers library and utilizes jQueryUI and YUI
user interface libraries, which are used to build CARIS's Spatial
Fusion Viewer. Users can create a new client using OSCAR-js and then
connect to Spatial Fusion Viewer for centralized site
The API is designed around the creation of thematic maps along with
optional functionality, such as selection or data download. OSCAR-js
supports the use of Open Geospatial Consortium web services.
The source code for the API is available on GitHub under the Apache
License 2.0. This will enable the development community to make their
own development branches for customization or as a way to contribute
code to the project. Building a distribution is done using Maven 3.
Source: CARIS press release