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Safer Seas 2011, Brest, France

Clearwater Instrumentation will be attending the Safer Seas 2011 conference in Brest, France, which runs from May 10-13. Clearwater’s Gary Williams will be presenting a paper titled “A Second-Generation Self Locating Data Marker Buoy” (PDF link) at the 4th International Workshop on Technologies for Search And Rescue and Other Emergency Marine Operations.

Our abstract describes why we’re so excited about our second-generation SLDMB: “Working from this refined set of specifications for the second generation SLDMB, we have solved the challenges of reducing the drifter physical size and achieved air deployment from an A-size sonobuoy tube with a novel deployment system that has been successfully demonstrated in trials at sea and air with nearly a 100% return of drift data on schedule by Iridium SBD.”

If you’re attending, please find us and say hello!

Clearwater has transitioned all of its equipment employing Iridium SBD messaging to the Iridium 9602. The new Iridium modem is smaller and easier to fit into hulls with limited space and is reported to make more efficient use of transmitting power. The 9602 also permits the pass through of an antenna feed which eases the use of dual band antennas for Iridium and GPS frequencies.

Clearwater has completed the development of their next generation instrument controller, the ClearSat-5.0, which will replace the ClearSat-4x series of controllers in the coming months. It has had its first successful application in our ClearSat-15, the SVP drifter. The ClearSat-5.0 employs the next generation MicroChip microprocessor the FF16HP which brings new levels of capability to our controller. The ClearSat-5.0 features a redesigned board with more I/O and fewer components on the board, assuring that our controller will have enhanced capability, while holding the line on pricing. ClearSat-5.0 will feature improved power saving features that drop sleep currents to 20 μa. ClearSat-5.0 will maintain compatibility with our suite of transmitters and sensors. We will still interface seamlessly with Argos 2 transmitters from Telonics and Kenwood, the Kenwood Argos 3 PMT and Iridium 9602 SBD modem.

Want a River Drifter at 400 KHz? There will be one here soon! The first River Drifters were fitted with Nortek Aquadopps with 1 and 2 MHz sensor heads and a four downward looking sensor for precision depth to bottom measurements. These drifting instruments are ideal for making detailed three dimensional profiles of shallow, active littoral environments. These River Drifters have working depths of 10 to 15 meters. Adding a River drifter with a 400 KHz Nortek Aquadopp will extend the profiling depth to 100 m. This new model will still offer the same advantages of autonomous surveying with sample records by Iridium SBD messaging and the ability to record 1 Hz Aquadopp data and GPS location data on internal storage.

Observing surface currents and tracking events for search and rescue operations requires a small, highly portable surface drifter that must be capable of being deployed from airplanes, helicopters and boats. The drogue plane and antenna must be protected during ejection from aircraft, yet hit the water and quickly assume their proper configuration with drogue planes and antenna deployed. Clearwater has solved these problems with a innovative packaging and deployment systems. Drifter GPS locations are returned to the user by Iridium SMB. All of this is in a compact shape that is 36 in. long and less than 5 in. in diameter, the required sizing for an A-size sonobuoy tube.

Clearwater has developed an Iridium RUDICS data transmitting system for handling up to 1 Megabyte of data daily from the world’s oceans and land. The ClearSat-RUDICS solution includes efficient and accurate data handling between observing equipment and the land-based server. A sophisticated packet tracking system ensures that all the data get through efficiently, even through rough weather conditions that often cause lapses in RF connections between equipment and Iridium satellites.

Clearsat-1 ADOS drifters outfitted with GPS, thermistor strings, and acoustic current meters capable of vertical profiling have been deployed in the Southern East China Sea with the goal of sampling the Kuroshio Intrusion. Researchers also hope to better understand several other processes occurring at multiple scales in the region. View a fascinating realtime depiction of positions over ocean depth contours, and read more about the experiment, at the QPE website.

Riverine drifter in Boston Harbor

Clearwater is pleased to announce the Riverine Drifter, a highly integrated, small, light-weight instrument designed for detailed surveys of currents and bathymetry in shallow environments. Riverine Drifter is a scaled down ClearSat-1 drifter instrumented with a Nortek Aquadopp modified with a fourth sensor for highly accurate bathymetric measurements, GPS location, 212 MB Compact Flash Card, and Iridium 9601 SBD modem. As it drifts with tidal currents, Riverine Drifter is able to take detailed profiles of 3-D current structure and depth all tied back to GPS time and geographic coordinates. Data excerpts can be relayed to the user via Iridium SBD. The entire data set is easily downloaded from the memory card. Sampling rates for Aquadopp and GPS can be as high as 1 Hz. Extensive field tests have been conducted in a variety of environments in Boston Harbor. Clearwater has shipped its first Riverine Drifters to Dr. Luca Centurioni at the Scripps Institution of Oceanography for use in studies of river discharge off the coasts of Southern California.

Photograph of Argos 3 PNT-K and antenna in Clearwater Instrumentation SVP drifter

Clearwater has completed integrating the new CLS Argos 3 PMT into applications for drifters incorporating Sea Surface Temperature, Air pressure and GPS location. These newly developed applications for the WOCE SVP drifter used in the Global Drifter Program, studies of surface circulation and observational operations offer potential advantages over similar equipment equipped with the Argos 2 PTT. Unlike the Argos 2 PTT the Argos 3 PMT receives a downlink message from Argos 3 satellites which informs it of the time, satellite ephemera, and PMT location. This information allows the PMT to transmit only in the presence of a satellite saving valuable energy which otherwise would be wasted. Early indications are that power requirements are reduced by 75% by not transmitting to an empty sky and that data returns are better than 95% because it only is sent when a satellite is overhead. In addition, improvements in data management by the PMT and in data processing by CLS can provide error checking, accurate sample times and advanced processing. Using Argos 3 means that a scientist can get exactly the accurately obtained data time series she wants.

Clearwater has completely upgraded its SmartSensor temperature string to make it smaller and lighter while improving its reliability and life. With a complete redesign of the MasterModem surface receiver and subsurface SmartSensor nodes, the new system is easier to handle and lasts up to 500,000 temperature-pressure cycles. The strings which are built on rugged polyethylene-coated steel mooring wire can be ordered with up to 20 nodes with temperature and pressure, or any combination of temperature-pressure nodes and temperature only nodes and lengths up to 300 meters.