JavaScript DHTML Menu Powered by Milonic
CODAR Ocean Sensors logo
CODAR Ocean Sensors - The Leaders in HF Radar Technology      

Past Events

CODAR Currents Newsletter Summer 092008 - header
SeaSonde Receive Antenna

Never resting on their laurels, CODAR engineering team members continually strive for improved system durability. Starting late this year the SeaSonde receive antenna will be replaced with an even more rugged version.

The new dome-shaped antenna design features a smooth upper profile absent of any screws reducing likelihood of any water intrusion.

Another advancement is the absence of external horizontal whip ground plane elements, with ground plane to be set inside the
mast for protection.

SeaSonde Receive Antenna This new design is completely backwards compatible with existing SeaSonde electronics, and will be included with all new SeaSonde remote unit or antenna replacement orders beginning late 2008.

Special Offer: Do you have an older receive antenna in your closet? For a limited time promotional trade-in discounts on older model receive antennae will be available!

Consult company for additional technical and pricing details.

Delivery inside 2008
New receive antenna design offers enhanced field robustness.

SeaSondes deployed in Qingdao, China
China’s State Oceanic Administration using SeaSonde data to support summer Olympics sailing events.

1200+ contiguous miles of coastline monitored Americas western coastal currents mapped by SeaSondes from Rosarito, Mexico up to Washington State.

CODAR’s New river monitoring product and its first overseas deployment
In April 2008 CODAR & Chinese hydrologists conduct the first RiverSonde deployment outside
of U.S.

Spotlight on Ligia Pacheco, Production
Meet the person putting the stamp of approval on every SeaSonde.

Are you up to date? SeaSonde 10 Release 5
Update 4 is now available.

Range Color Maps How to use these for detecting changes in sea echo.



World's Largest Coastal Current Mapping Network Realized

West Coast SeaSonde Mapping Data
Click image to enlarge
A vision shared by many U.S. West Coast oceanographersfor over 10 yearswas made a reality this summer with realtime mapping of surface currents along more than 1,200 contiguous miles of coastlinestretching from Rosarito,Mexico past the  southern border of Washington state. Technicians from the CaliforniaCoastal Ocean CurrentMonitoring Program (COCMP) installed the final systems to link the SeaSonde® networkin Oregon, operated by OregonState University, and the COCMP-managed SeaSonde systems in Northern California.Almost 60 SeaSondes arecontributing real-time data with coverage reaching nearly 200 km offshore andhigher resolution networks monitoringaround urban areas. Some of these units have been operating in small pocketsaround the Santa Barbara Channel, MontereyBay and off Newport, Oregon, since the early 1990's.The collection of smaller networks were linked andexpanded using 40 new SeaSondes purchased anddeployed under the California Clean Water, Clean Air,Safe Neighborhood Parks, and Coastal Protection Actof 2002. This network will be used for monitoring,studying and protecting the Pacific coastline of the U.S.and Mexico and is already a model for future large scalenetworks worldwide.

For near real-time National HFRadar Network(HFRNet) maps and information, visit:

Image courtesy of Lisa Hazard,Scripps Instituteof Oceanography

Let The Games Begin!
SeaSonde® Mapping Currents at
Olympic Sailing Race Area in Qingdao

For those asking, “what could top the colorful and dynamic Beijing 2008 Olympics opening ceremony?”, we have the answer: SeaSonde derived current maps of the sailing race area in Qingdao!

At the stroke of midnight 8 August (Beijing Standard Time) the North China Sea Marine Forecasting Center of State Oceanic Administration (SOA) began posting SeaSondeproduced hourly surface current maps on their Olympic Games Environmental Observation and Forecasts web site. Data will be provided to the public throughout the Olympic and Paralympic sailing event periods, taking place in August and September, respectively. The SOA is also using SeaSonde data along with other environmental data sets as input to Princeton Ocean Model creating marine environmental forecasts of the region.

The SOA North Sea HF network consists of two SeaSonde radar units spaced approximately 20 km apart. The SeaSonde unit on isolated Dagong Island requires only 300 watts power that is generated by wind turbine feeding into a battery array. Data from both radar units are transmitted hourly back to SOA North Branch headquarters office via wireless microwave radio relay.

CODAR company President and Co-founder Don Barrick had this comment, “Since my days at NOAA during the 1970’s there has been discussion of using HF radar data in support of sailing race events. I have waited too many years, and it may be half a world away, but it is now being done, and quite well! I applaud the China State Oceanic Administration for breaking new ground in the application of HF radar data from our SeaSonde systems. Thank you for pushing the envelope forward.”

Typically winds play a major role in race strategy; nonetheless, knowledge of the currents may provide an edge needed to win. However, Qingdao is notorious for occasional periods of extreme calm during summer season, and under such conditions knowledge of the ocean current structures may take on greater importance. Shown here is a snapshot of the SOA’s HF radar web page, where near real-time maps are posted hourly. The current maps, on a 500m resolution grid, reveal a very strong tidal signature in the Qingdao region. Particularly strong jets reaching current velocities in excess of two knots are seen occurring inside the race circles (these are very near to shore) during portions of the tidal cycle. Some very interesting current patterns have been revealed.
click image to enlarge
SOA web page
Snapshot of the SOA web page:
Qingdao SeaSonde installations - Olympics 2008
click images to enlarge
Qingdao SeaSonde montage

Introducing the RiverSonde®

Expanding the radar product line, CODAR Ocean Sensors is now offering the RiverSonde®, an affordable, non-contact monitoring system used to measure water flow in rivers, streams and channels. It measures and records mean surface velocities and from these can generate velocity profiles. These data can be used in conjunction with additional relevant data to calculate total water volume flow (discharge). RiverSonde is used to study river flow properties and effects, and used by anyone interested in these properties, including geologists, water resource scientists, agricultural managers for irrigation, flood control/emergency response, and wildlife managers. It is also ideal for monitoring river movement during flood events when in-situ measurements are either unavailable or extremely dangerous to obtain using traditional methods.

RiverSonde Antenna installation

RiverSonde vectors data
Profile representing a cut directly across swath of vectors extending out from the radar.

One of the outputs from the RiverSonde is a onedimensional map of surface current radial velocities. An example of raw data from the San Joaquin River at Vernalis in California is shown here; approximately 2800 radial current vectors are plotted using an angular resolution on 1. While this plot only includes data covering about 150 seconds, the RiverSonde continuously measures cross-channel radial velocities and can average over longer periods.

RiverSonde radial currents data
Radial currents for one 2.5-minute data segment.
RiverSonde velocity data

These one-dimensional velocity map outputs from a RiverSonde can be combined with those from additional RiverSondes to create continuous realtime two-dimensional vector maps of surface current velocity and direction, in similar manner as SeaSonde, but on a smaller scale (spatially and temporally). Synoptic measurement of 2D velocity distributions in river flows such as this is not possible using any other technology.

This system is designed for operation at river's edge, in populated or remote locations. Robust hardware and software allow automated operation and data processing, even under extreme weather and/or vessel traffic conditions when other in-situ devices routinely fail.

Development began at CODAR Ocean Sensors in 1999 with funding from the US Geological Survey (USGS), whose aim was to see a non-contact alternative to present stream gauging methods. With promising initial results, R&D continued, with prototype units having been deployed and operated successfully in several western U.S. locations.

The RiverSonde is now commercially available. A complete set of product information will be available shortly at the company web site.

RiverSonde® Debuts in China

Many of the populous cities inside China are set immediately adjacent to rivers, in their middle and downstream sections. Over the centuries some of these rivers experienced considerable silt accumulation and sit actually higher than the nearby occupied land. Inside rainy season the storm runoff from mountainous areas leads to significant water volumes inside the river channels eventually passing through major urban areas. With recurring high risk of flooding, China’s Ministry of Water Resources (MWR) has responsibility to make the important decisions on when and where to release waters for ensuring safety in the higher density urban areas. No decision is an easy one, for even the “flood plain” release sites are often sites of villages and important farm land.

MWR team assembling the antenna
RiverSonde - Shandong

Earlier this year the MWR installed their first RiverSonde at the Yi River, inside the Shandong Province. MWR assigned a full technician, scientific and operations managerial crew to participate in this groundbreaking event

RiverSonde - Shandong

Television news crews captured the event on film and interviewed MWR directors who expressed their pride in China embracing cutting-edge technology for the important public service of flood control management.
RiverSonde - Shandong

Shown here is RiverSonde antenna being installed next to a memorial placard recognizing major flood disasters of past years in which thousands perished.
RiverSonde - Shandong

CODAR Spotlight ~
Ligia Pacheco, Production Manager

Some may not realize that CODAR sits in the heart of the Silicon Valley in northern California. Given our geographic presence, two blocks from Google headquarters, 2 miles from Moffett Air Base and 15 minutes from Stanford University, it is not surprising that many of the CODAR staff have played roles in the computer semiconductor and defense industries, technology sectors that gave this region its nickname. The story of Ligia Pacheco, CODAR’s Production Manager is a good example:

Ligia began her career in 1973 at Fairchild Semiconductor doing assembly inside the PC board department-- Did you know anyone who owned a computer then? No, this was a time when the only PC systems were owned by government agencies built for very specific purposes. It was an exciting time at Fairchild and the fledgling PC industry. During this the year Fairchild introduced the industry’s first functional device with dielectric isolation of both emitter-base and base-collector junctions, and dramatically reduced system component sizes. Though this was Ligia’s first job, she was quickly promoted into leading a team of assemblers.

Ligia Pacheco, Production Manager
Within Fairchild as well as other high-tech companies she worked for subsequently, such as Trimble Navigation, Siemens, and Mirage, much of the production work were one-of-a-kind prototypes that required high-precision manufacturing almost entirely done by hand. For Ligia, the thousands of hand solders required for prototype 6-layer circuit boards is enjoyable, like, she says, “putting together a big, beautiful crossword puzzle”. While the use of automated, machine board assembly has increased, it has still been those sectors wanting the highest quality and precision that require her types of skills.

When CODAR founders decided to bring SeaSonde to commercial status in 1993, Ligialeft Mirage and joined CODAR full-time. Since then and up until the early 2000s,Ligia handbuilt every SeaSonde and every HF prototype designed at CODAR. In recentyears as the company has grown, she has passed her skills on to several otherCODAR staff members. Still, she prefers to work on the prototypes directly, asshe says it is her passion and she does not want to give up the favorite partof her job.

It was in the late-1980s while working at stealth defense company
Mirage that she met the CODAR company founders and was hired to hand assemblethe first prototype SeaSondes. At that time CODAR was a very young company andso the board assembly and other work was performed on weekends inside the garageof a company founder’s home—does this sound like the story of Hewlettand Packard?!
This year we celebrate Ligia’s 15th year at CODAR and bring attention to her important contributions to this industry!

Software News ~ Are You Up to date?

SeaSonde 10 Release 5 Update 4 is now available and shipping on all new SeaSonde systems. Release 5 Update 4 is compatible with OS X 10.5.x (Leopard).

OS X 10.4.11 (Tiger) or above is recommended but the update is also compatible with OS X 10.3.9 (Panther). Release 5 Update 2 and earlier SeaSonde software versions are NOT compatible with OS 10.5.x (Leopard). All of the Mac OS incompatibility issues in Update 3 and earlier versions have been corrected in Update 4. You can download Update 4 from:

Please contact us if you have forgotten the login information for the password protected site.

Additional software update information is available inside CODAR's customer support web area at:

Tech Tips

How to Use Range Color Map for Instantaneous Detection of Change in Sea Echo Signal

The range color map is like a digital color plotter that paints a row of colored pixels with every sweep. The intensity of color in each pixel represents the echo signal strength in each range cell. Its rapid updating (within 0.25 - 1 seconds) makes it extremely useful for instantaneous detection of changes in sea echo signal strength. Here is an example of how it can be used:

Suppose I want to know how much of the signal seen in the spectra (top image) is being produced by my SeaSonde (in backscatter mode) and how much is coming from an unidentified bistatic source (that is, another SeaSonde located somewhere else but operating on the same frequency).

Open “Range Color Map” under SeaSondeAcquisition’s“ Monitor” pulldown menu. Note the color intensity on the right margin for a few seconds then turn the transmitter’s power switch off. Check the right margin again and what remains is signal from an outside source. Then remotely connect to the suspect bistatic source and briefly turn off its transmitter via SeaSondeController. If the remaining signal goes away, you’ve confirmed the source in just a few seconds time. Other applications include confirmation of transponder peaks, ionospheric echoes, and RF interference.

Range Color Map


IEEE/MTS Oceans ’08
Quebec City, Canada
15-18 September 2008

St. John’s, Newfoundland & Labrador
15-18 October 2008

Ocean Innovation
St. John’s, Newfoundland
20-22 October 2008

Register for the upcoming
Fall 2008 SeaSonde
Training Course

Mountain View, California
3-7 November 2008
Details can be found on the company web site at:

CODAR Fall Training

Lipa, B., et al, HF Radar Sea-echo from Shallow Water, Sensors, 2008,
vol. 8, pp. 4611-4635, DOI: 10.3390/s8084611.

M. Menna, A. Mercatini, M. Uttieri, B. Buonocore, E. Zambianchi
Wintertime transport processes in the Gulf of Naples investigated by HF radar measurements of surface
currents, Il Nuovo Cimento, 30 C (6): 605-62, doi: 10.1393/ncc/i2008-10270-0.

Ramp, S. R., D. E. Barrick, T. Ito, and M. S. Cook (2008), Variability of the Kuroshio Current south of Sagami
Bay as observed using long-range coastal HF radars, J. Geophys. Res., 113, C06024, doi:10.1029/2007JC004132.
Visit our company website for an extensive list of publications.

If you have any questions, please email us: CODAR Ocean Sensors logo

1914 Plymouth Street
Mountain View, CA 94043 USA
Phone: +1 (408) 773-8240
Fax: +1 (408) 773-0514


© CODAR Ocean Sensors 2000 - 2021
About CODAR | Intro to HF Radar | News | Products | Support | Contact Us | Help | Partners Sales Support