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RiverSonde® Grants
Available
CODAR offers at least two RiverSonde equipment loan grants for graduate students
in 2010
Proposals due by 31 March.
It least two equipment
loan and travel expense
grants are available for year
2010 that include use of a
RiverSonde unit.
CODAR Ocean Sensors, Ltd. is
seeking proposals outlining
novel applications of
RiverSonde in river, lake,
estuarine, harbor, or ocean
environment. Novel
applications could be (but not
limited to) measurement of
near-shore ocean rip currents or
flows at river intersection with
ocean or lake, integration of
RiverSonde data with other
data sets collected inside of a
regional ocean observing
system, and use of RiverSonde
data to improve or validate
coastal or river hydrodynamic
models, etc. Motivated
graduate students interested in
hydrology, oceanography or
other related subjects are
encouraged to apply.
Award Highlights:
• Grantee has use of RiverSonde
for up to 3 months.
• CODAR engineer will travel
to assist with equipment
installation and provide a
training course to grantee and
their associates at grantee’s
institution or deployment site.
• $1,300 in travel funds also
provided by CODAR for
grantee to present their results
at a scientific conference/
workshop pre-approved by
CODAR (payment made to
grantee upon abstract
acceptance).
• Grants are limited to
equipment use inside of the
United States. Future grant
programs may be offered for
other regions.
Applications will be accepted 1
February- 31 March 2010.
Review of proposals and awards
will be conducted on a
continuous basis throughout
period, so early submissions are
encouraged. All awards will be
announced by or before end of
April 2010.
Complete grant details are
posted at CODAR company
web site at http://www.codar.com/
news_01_1_2010.shtml
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COCMP SF Bay - Gulf of Farralones Node
Personnel shown (left to right):
Toby Garfield, Chris Raleigh,
Jim Pettigrew,
Max Hubbard, Matt Gough
Figure showing a 25 hour average of surface
currents in
the Gulf of the Farallones and San Francisco
Bay. Data
are from the San Francisco node combined
with data
from the Bodega and Monterey nodes
on
2010-01-25.
Point Bonita lighthouse and fog station.
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A Peek Inside California’s Radar Network
The HF Radar team at San Francisco State University’s
Romberg Tiburon Center face variety,
beauty& sometimes danger all in a day’s work
Contributed by Jim Pettigrew, SFSU
RTC
Through California voter-approved bond funding, the Coastal Ocean
Currents Monitoring Program (COCMP)
was established to
measure coastal surface circulation
along the whole California Coast.
Initially started in 2005, COCMP
is now an array of nearly 60 CODAR
SeaSondes covering the whole coastal
region from the Oregon border south
to the Mexican border. In order to
provide complete coverage, and also
to
offer higher resolution in areas
of
high potential impact from buoyant discharges in regions with high population,
the network is designed as
“nested” with standard and high resolution
systems embedded within the
broader Long-Range coverage area. The
entire coast is mapped with an
array of nine Long-Range (5 MHz) systems
to provide 6 km resolution of
surface currents from the shore out
about 180 km. Between Bodega and Big
Sur and
in the Southern California Bight, arrays
of standard range
systems operating at 12 and 25 MHz
provide 3 km and 1 km resolution
of the currents
within 80 km of shore. In San Francisco
Bay-- an area that is
quite dynamic and at high risk for
environmental incidents--an array
of four 42 MHz SeaSondes
offers 0.4 km spatial resolution
for the currents
in the central portion of the Bay.
This high-resolution portion of network
provided
important current information during
the response effort to Cosco Busan oil spill of 2007.
The COCMP system is subdivided into
eight “nodes” each of which is responsible
for the
operations and maintenance of the
radars in its geographic region.
Our Romberg Tiburon
Center (RTC), part of San Francisco
State University, operates the
San Francisco Bay and
Gulf of the Farallones node whose
coverage extends from Point Reyes,
south to Pillar Point
and into San Francisco Bay. The
RTC node consists of 10 SeaSonde
units and is the only
node to include instruments operating at all the basic SeaSonde
frequencies: 4-6 MHz, 12-14 MHz,
24-27 MHz, and 40-44 MHz. Operations
of the RTC
node are under the leadership of Toby Garfield and managed by Jim
Pettigrew, with assistance from Chris Raleigh, Matt Gough and Max
Hubbard.
Six units are on Golden Gate National
Recreational Area properties for
which U.S. Park Service been a terrific
partner.
We also maintain sites on properties
administered by the Air Force, the
Coast Guard, and the cities of San
Francisco, Sausalito and Montara.These
radar locations are each quite interesting.
One of our Long-Range SeaSondes resides
at Pillar Point directly above Mavericks
, the famed big-wave surf break,
while a 12 MHz unit in Bolinas sits
on the property of the historic Marconi
ship-to-shore transmitter array which was built in
the early 1900’s. Visiting these
locations offers both beauty and
a little bit
of history.
Not all locations are created
equal and some pose logistical and
physical challenges: Our first radar
set at the Romberg
Tiburon Center facility was easy
to install and is conveniently accessed
by stepping directly outside our
office doors. In contrast, our
latest site, a 25MHz unit at the
Point
Bonita Lighthouse and Fog Station,
took several years working through
bureaucracy to receive land use
approvals from the Coast Guard and
visiting this site is not for the
faint of heart. |
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After a long hike,
then passing through a narrow tunnel
with low clearance, to reach the
antenna
location one needs to suppress vertigo
while walking on a swaying footbridge
above a perilous chasm. The antenna
is bolted to a ledge of pillow
basalt high above surging waters
and the blast of the fog horn requires
ear plugs be worn at all times. The
demonstration of bravery and the
extra
effort RTC staff make to operate
at this location is justified as
the radar has a 240-degree field
of view and provides 1km resolution
coverage of
the treacherous waters of the San
Francisco Bar and Golden Gate Channel..
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Snapshots below highlight journey to SeaSonde location at Point Bonita Lighthouse.
All Images provided courtesy
of Jim Pettigrew, SFSU Romberg
Tiburon Center |
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| Entrance to the Point
Bonita tunnel |
Tunnel’s slippery,
low-ceilinged
passageway |
Corroded cables
limit traffic to two
persons at a time |
Footbridge to Pt.
Bonita Lighthouse |
SFSU grad student
Max Hubbard
assembling radar
antenna |
SeaSonde antenna
sits about 15m
above the water |
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Who Would’ve Known? Seasonally Recurring
Giant Eddy
Seen Off California
Remember the fascinating double-gyre structure Jeff Paduan discovered off Monterey
Bay 15 years ago from SeaSonde
current maps? A bit over a year ago,
Greg Crawford and Shannon Stone (of Humboldt
State); Chris Halle and John
Largier (of Bodega Marine Laboratory)
found a giant eddy lurking off Mendocino
with their recently installed Long-Range
SeaSonde at Shelter Cove, combined with
the unit at Pt. Arena. This eddy, they
determined, was produced by the NNW winds
that drive upwelling off the coast during
August - October every year. It is a
regular visitor during this period.
As the resulting cold-water jet, up to
2 knots near the coast, flows to the
South, it becomes an anticyclonic eddy
that has a
mammoth diameter up to 170 km. Entraining
warmer water in its center, shown by
the lighter color in these consecutive
figures the colder coastal waters are
swept offshore around its Southern edge.
Although the example here was seen in
2008, we
can attest that this same huge eddy was
the most prominent eye-catching feature
seen in the zoomed-out West-Coast HFR
Net
data during the same period in 2009.
These long-range radars are part of the
COCMP network that now comprises 60 SeaSondes
covering the State of California.
Many of the radars are shorter-range,
higher-resolution units centered around
populated areas and bays. But the long-range
systems span the shelf, and when combined
with satellite observations like temperature,
reveal fascinating dynamics that
impact biological fisheries productivity
we depend on along our West Coast. As
the upwelling winds die (wind shown as
the red
arrow), this fascinating feature disappears,
and a relaxation phase with weak Northerly
flows dominates near the coast the
remainder of the year.
The authors of the AGU presentation in
which this discovery was displayed used
animations they called “particle backtracking”
from the SeaSonde current maps to determine
the origins of the water from a grid
of points within the eddy. This type
of
analysis reveals the surface water pathways
and length of time it takes floating
particles to traverse the region. The
figures
below are from that presentation.
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| On the Horizon: Reducing Power Consumption at SeaSonde Locations |
| Why does the CODAR set industry records only to break them shortly after? Because
innovation is the key to expanding utility! CODAR engineers are working
to lower the entire radar site power requirement by as much as 40-90% of
present needs. In this latest development effort CODAR engineers are reducing
the power requirement to an average of 150 watts for the SeaSonde radar
AND cooling system. This ultra-low power system is ideally suited for remote
areas where renewable power sources or operation from generators is only
viable option. Read on to learn about this exciting work... |
Development Impetus
When calculating the total power required at any radar site, you need to factor
in the consumption of the radar plus that of any associated infrastructure
at that location. Temperature and humidity control for the electronics enclosure
is the potential biggest power draw at the radar site. In mild climates, keeping
the electronics within optimal temperature ranges can often be achieved with
a simple heat exchange fan that draws only 25 watts power. In contrast, cooling
the electronics in warmer climates or stagnant air becomes more complicated;
simple low-power heat exchangers are not adequate for the task and in those
cases use of a closed-loop air conditioning system is required. Though power
for a SeaSonde radar is only 350-450 watts, air conditioners can sometimes
require up to 1.5 kilowatts of power-- over 4 times that of the SeaSonde itself. This poses a problem when power must be derived solely from renewable sources
(e.g. solar or wind), presenting logistical challenge and high cost. |
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Prototype Class-E transmit amplifier shown here. |
Reducing Power With New Design Features
Highly Efficient Transmit Amplifier
The conventional SeaSonde transmit amplifier efficiency is 30%, which
is standard for Class-AB
amplifiers designed for use at HF. CODAR engineers have developed and
will be utilizing a
breakthrough design Class-E transmit amplifier having an TX efficiency
over 80%. This not only
reduces the amount of required power input to transmit amplifier but
also the amount of heat
generated that would otherwise need dissipation.
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Electronics Packaging & Built-In Cooling System
A key consideration to maximizing system efficiency is heat management. The entire
electronics layout is being revamped to optimize heat dissipation inside the
system. The transmit and receive electronics are stripped from the traditional
two 19” electronics chassis and assembled together into one small package,
roughly 0.75m height x 0.5m width x 0.5m depth. This sealed case is weather
resistant and suitable for both indoor/ outdoor use. A cooling system is built
into casing with a temperature sensor inside electronics allowing for intelligent
auto on/off.
System Requirement
With an average draw of 150 watts, the power requirement will vary throughout
normal operations from 130 watts - 200 watts, based on the local temperatures
(and hence internal air cooling requirement). Any power generation system should
be engineered to at least 150 watts under any expected local weather conditions.
Consult CODAR for additional information.
Wind turbine supplying power to a SeaSonde in Alaska. Image courtesy of Rachel
Potter, University of Alaska, Fairbanks |
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Software News:
SeaSonde Release 6 Offers
Exciting Features & Convenience
As of September 2009, CODAR released our most user-friendly radial site software
yet. Release 6 comes with a number
of improvements to make set up
and
maintenance of your radar sites
easier while also providing more
robust operation.
If you are the squeamish type
when it comes to new software
releases, fret not. Months of
in-house and beta testing on
operational systems have made
our latest update one that is
very stable and ready for prime
time.
The feature we are sure will
make every technician’s life
easier is our
new Radial Web Interface. We’ve
utilized some of the latest
technologies built into Mac OS
X 10.6 Snow Leopard, including
Ruby On Rails, to create a password-protected
interface to the radial
site data and diagnostics that
is accessible via any standardscompliant
web browser. No special app is
necessary. You can log on
from a friend’s computer or even
your iPhone or Blackberry. With
built-in email alerts, you can
be notified while on the go and
diagnose most issues directly
from your mobile phone’s browser.
With the one-click download of
a system report that covers
computer, hardware and data quality
checks, it’s never been so fast
and easy to get a snapshot of
radar site health.
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CODAR support engineer Hardik
Parikh enjoys a latte at a sunny
California cafe while accessing and
checking status of a SeaSonde
operating in eastern Canada through
his iPhone.
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While we’re sure you’ll enjoy using the Radial Web Interface, we’ve also made
big changes to our on-board applications
that technicians will appreciate whether
novice or expert. Are you tired of siting
the antenna’s black arrow bearing, correcting
for magnetic declination and then adding
45° to get the loop 1 bearing? If so (or
if the last sentence just completely confused
you), don’t worry, our improved Radial
Setup App means you only have to remember one number and it takes care of the rest. Only the essential information is
required and a new layout makes it easier
to remember what is important. SeaDisplay
and SeaDisplay Setup are also much easier
to use. Easier navigation control has been
added for setting up site maps and oneclick
buttons on the toolbar are now available
to perform common tasks like making radial
distribution plots.
Release 6 is also compatible with our latest Multi-Static Data Processing software
package. Do you have radars in your network that are synchronized on the same
frequency using our patented SHARE technology but are not producing elliptical
vectors? If so, then you’re letting your data go to waste! To find out if Multi-Static
software is right for your network, contact your favorite CODAR representative.
You can see results of our most recent elliptical validation study in the latest
issue of Remote Sensing: Lipa, B., C. Whelan, B. Rector, B. Nyden, HF radar bistatic measurement
of surface current velocities: drifter comparisons and radar consistency checks,
Remote Sens., vol. 1, pp. 1190-1211. 2009
Not quite ready to process your Multi-Static signals for currents? You can still
utilize SHARE with our Multi-Static Source Monitoring feature. Whether or not
you have the Multi-Static software package for currents installed, this allows
you to monitor the transmit signal from other sites in your SeaSonde network
that are synchronized using SHARE. This monitoring feature that comes included
with Release 6 allows you to track any changes to antenna pattern characteristics
and log them over time – an important tool in QA/QC of your data.
There are many more under-the-hood changes in Release 6 that make SeaSonde radar
site operation more robust and user-friendly. To see if your computer and operating
system are compatible with Release 6 or to download the installer, please visit
our support website at http://support.seasonde.com or contact a CODAR representative
today. |
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A Look Back In Time... The Birth of CODAR at NOAA
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The first HF radar to demonstrate and validate current and wave measurement capability
was built between 1969-1973 in a program led by DARPA and NOAA, in
cooperation with Scripps Institution of Oceanography and Stanford
University. Designed by Donald Barrick at NOAA Environmental Research
Laboratories (ERL), the radar with its conventional 500-meter long
phased-array antenna was bulky and inconvenient for deployment, but
proved the point that HF radar is a viable tool for measurement of
ocean current and wave parameters.
After the initial success, NOAA's ERL commissioned Dr. Barrick in
1972 to develop a practical replacement for the large and expensive
phased array antenna design. The technology resulting from this NOAA
program was called CODAR, an acronym standing for Coastal Ocean Dynamics Applications Radar.
In 1977 the prestigious journal Science published an article on the
demonstrated CODAR success. Shortly after, in 1978 the NOAA team
that developed CODAR was awarded the U.S. Department of Commerce
Gold Medal Award. Various patents relating to the technology were
granted within the NOAA group starting in 1979.
In the early 1980s, the core team that invented the original CODAR
was encouraged by NOAA to move into private industry, to continue
the technology evolution and provide a commercial source for institutions
to acquire HF radar equipment. That company became CODAR Ocean Sensors,
Ltd. The technology has evolved from original CODAR radar and is
now the SeaSonde®. It remains the only commercially available HF radar system that is based on
the groundbreaking compact HF radar concept developed and patented
inside NOAA, while all other HF radars still utilize the phased array
approach that was abandoned back in the 1970s. As of 2010, the SeaSonde
represents over 85% of all HF radars ever built and used for ocean
current and wave measurements, with systems used in 22 countries.
Photos illustrate the current mapping HF radar antenna evolution.
Starting with image #1: 500-m long phased array radar at San Clemente
Island, circa 1972. Smaller inset image shows the trailers used to
house the radar electronics and computer system. Image #2: the first
NOAA-built CODAR antenna system consisting of a square monopole receive
array with direction-finding closed-form solutions for bearing. Smaller
inset image shows the electronics and DEC PDP-11/23 computer and
tape drives used for near-real-time processing and archival. Image
#3: The first crossed-loop CODAR antenna, built of copper. Image
#4: a later version of crossed-loop CODAR antenna, built of PVC.
Image #5: Successor to CODAR, the SeaSonde. Image #6: Latest SeaSonde antenna system with all
transmit and receive elements colocated atop a single mast. The unit
shown is located on Scripps Pier in La Jolla, California. Image #7
shows latest SeaSonde electronics system, consisting of a small but
powerful mini-processor and two 19” electronics chassis. |
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In January 2010 the Regional Government of Andalucia has confirmed funding to
a
“Proyecto de Excelencia Investigadora”
program that includes a 1-year temporary
deployment of two 25 MHz SeaSondes in
the Gibraltar Strait. This new program
is under
the scientific leadership of Cadiz University,
with the operational coordination of
Puertos del
Estado and with the participation of
Sasemar, Instituto Hidrográfico de la
Marina, Instituto
Español de Oceanografía, the Harbours
of Algeciras and Ceuta, Malaga University,
Abdelmalek
Essaâdi University of Tanger, Naval Postgraduate
School Monterey, Empresa de Gestión
Medioambiental de Andalucía, The Spanish
and Moroccan Society for the Study of
Transport
Communication Across Gibraltar Strait,
Natural Park of the Strait, and the engineering
company QUALITAS Remos. The official
project title translates roughly to “Current
monitoring by means of coastal HF Radars
as a core element of the Operational
Oceanography System of the Gibraltar
Strait”. Installation of the radars will
happen in Cape
Carnero and Ceuta Harbour inside 2010.
This could very loosely be described
a “re-deployment”, as 28 years ago CODAR
units
(predecessors of the SeaSonde) operated
in this Northwest Alboran Sea area. Named
“Donde Va”, the 1982 field campaign objective
was to study gyres created by the jet
inflowing through Gibraltar from the
Atlantic. This was a multinational program
that included joint tests between National
Oceanic and Atmospheric
Administration (NOAA) Wave Propagation
Lab and Naval Research Lab (NRL) in Stennis,
Mississippi. NRL group focused
on satellite and aircraft remote sensing
with the CODAR HF radar work carried
out by NOAA.
For further reading on the 1982 deployment
and results, we recommend: Janopaul,
M. M., Frisch, A. S., CODAR measurements
of surface currents in the northwest
Alboran Sea during the Donde Va experiment,
Annales de Geophysique, vol. 2, no. 4,
pp.
443-448. 1984 |
Carnero lighthouse at Cape Carnero.
View from the Ceuta Harbour breakwater. |
Transmit & Receive With a
Single-Mast Antenna System |
For over a decade SeaSondes operating between 24-50 MHz frequency band
have an antenna system that co-locates
both transmit and receive antenna
elements atop a single mast. Recently this
capability to operate with a
single-mast antenna system has been expanded
to include lower frequency bands
down to 12 MHz.
Though a traditional two-mast antenna system
– one for transmit antenna and
one for the receive antenna – is already
extremely compact by conventional HF
radar standards, a single mast antenna
system represents a critical practical
convenience when installing in congested
urban areas, on oil platforms or atop
other manmade structures.
The first 12 MHz combined antenna systems
were purchased by Scripps Institution of
Oceanography (SIO) for use on oil
platforms in the Gulf of Mexico. Shown
in photo are CODAR company President Don
Barrick and Tom Cook of SIO
with the first 12 MHz combined antenna.
This unit was delivered to SIO in 2008. |
SIO’s Tom Cook (left) with CODAR company
President Don Barrick
and the first 12
MHz
combined antenna. |
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UPCOMING
EVENTS
CODAR
WILL BE EXHIBITING AT THE FOLLOWING UPCOMING
EVENTS:
Ocean Sciences
22-26 February 2010 Portland, Oregon
Oceanology International
9-11 March London, England
SeaSonde Training Course
3-6 May 2010 Northern California
2010 The Meeting of the Americas
8-13 August 2010 Foz do Iguacu, Brazil
We recommend participation in the OS02 session:
Application of HF Radar Networks to Ocean
Forecasts.
Links to these conference official web sites
can be found in Upcoming Events Section of
CODAR home page
www.codar.com
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Important Announcement on Not-to-Miss Meeting this Fall:
High-Frequency Radar Workshop 2010 (HFRW 2010)
Theme: Global Forum on HF Radar Applications & Coordination
Workshop Purpose and Objectives
High-Frequency (HF) radar systems and networks
are employed in a variety of operational,
societal and research
applications. SeaSonde HF radars are now
used widely for such purposes and represent
over 85% of all HF radars used
for ocean monitoring. The theme of the
High-Frequency Radar Workshop (HFRW 2010)
is “Global Forum on HF Radar
Applications & Coordination”. The workshop program addresses the application of data from these
HF radar systems and
networks, with focus on several key application
areas, and also addresses some critical
issues with designing, building
and sustaining an HF radar network to serve
the needs of a variety of users. The workshop
objective is to bring greater
understanding of these topics to those
agencies or key persons who are or will
be responsible for funding, designing and
implementing a multi-application HF radar
network, and to those entities or individuals
who may benefit from the data
products.
Format
The workshop is organized so that leaders
in these fields will select subjects and
speakers within topic-oriented sections.
These sections would be conducted as talks
followed by panel discussions, among the
panel members and the other
participants. Hence a primary goal is to
introduce to, and promote among new and
existing users, the latest important
applications of this vibrant, growing technology.
Details
When: Fall 2010. Exact dates to be announced
in Spring 2010. Workshop will occur across
a 4 day period.
Where: United States. Specific location
to be announced in Spring 2010.
Contact: If you are interested in participating
in the upcoming HFRW and wish to be added
to conference mailing list or
have questions on this subject, please
contact the HFRW meeting administrator
Allison Mendes at phone +1 (408)
773-8240 x23, or send email to HFRW@codar.com.
Details on HFRW will be posted on CODAR
company web site at www.codar.com.
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If you have
any questions, please email us:  |
1914 Plymouth Street
Mountain View, CA 94043 USA
Phone: +1 (408) 773-8240
Fax: +1 (408) 773-0514
www.codar.com |
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