ST Company ProfileTeledyne RD Instruments: Measuring Water in Motion and Motion in Water
The RiverRay ADCP.
San Diego, California-based Teledyne RD Instruments Inc. (TRDI) celebrated in May its 30th year since shipping its first acoustic Doppler current profiler (ADCP), and its 20th year since shipping its first Doppler velocity log (DVL) and first river ADCP.
Like many marine instrumentation companies in the 2000s, TRDI has seen significant expansion in its third decade. At the same time, it has supplied a thriving demand for its ADCPs and DVLs, with shipments of more than 1,200 units each year. The company quadrupled its business since 2000 and is part of Teledyne Technologies Inc. (Thousand Oaks, California), after being acquired in 2005.
TRDI designs and manufactures underwater acoustic sonar products for current profiling in marine and inland waters, wave measurement, underwater navigation, imaging and diving applications. It is separated into three areas: marine measurements (ADCPs and wave-measurement products for coastal and deepwater oceanographic environments), navigation (precision navigation, imaging and diver products, and government build-to-print contracts) and water resources (discharge and flow-measurement products for inland environments).
In August 2005, RD Instruments was acquired by Teledyne Technologies Inc., the first of several Teledyne acquisitions within the marine industry that led to Teledyne Marine, a collective of 10 long-standing oceanographic product manufacturers and service providers. Teledyne Technologies, which has a 50-year heritage, serves various niche markets.
Located outside San Diego, about 7 miles from the site of the original factory, TRDI employs 200 multidisciplinary scientists, engineers, technicians, sales and support personnel. The company occupies 80,000 square feet in an ISO-9001:2000 certified facility that includes engineering, laboratory, manufacturing and test areas.
TRDIís factory houses production facilities, computerized design capabilities, transducer development and manufacturing capabilities, automated transducer and system test tanks, and a range of test boats for verifying system performance on nearby lakes, San Diego Harbor and the Pacific Ocean. There is also a secured facility for government research, development and manufacturing. TRDI offers the design of sonar systems, transducers and low-power electronics, and full-scale and original equipment manufacturer production, as well as build-to-print contracting. TRDI also has a commercial network for worldwide sales, service and support, and maintains offices in France and China with a global network of trained local representatives.
Guiding the company are Bill Kikendall as general manager and several vice presidents: Harry Maxfield (sales and marketing), Ed Tyburski (engineering) and Mark Sturhann (manufacturing).
Deployment of ADCPs in Climate Monitoring
Two long-standing programs use TRDIís ADCPs to improve scientistsí understanding of global climate. These are the Global Tropical Moored Buoy Array program, which has deployed moored ADCPs since 1988 in deep-sea equatorial oceans, and the Oleander Project, which has made weekly underway measurements of upper-ocean currents since 1992 while crossing the Gulf Stream.
Work that started 30 years ago in the equatorial Pacific to study El Niño-Southern Oscillation events has developed into the Global Tropical Moored Buoy Array, which is now a multinational effort that spans the equatorial belt around the globe. Scientists at NOAAís Pacific Marine Environmental Laboratory and their international partners moor ADCPs to monitor currents, mixing and circulation patterns in the ocean surface layers.
These programs address long-term climate and seasonal weather patterns affected by ocean currents, e.g., hurricane activity in the Atlantic and monsoons in the Indian Ocean. Of particular interest have been ADCP records of changes in a subsurface, jet-like current called the Equatorial Under≠current. Its variability, both in time and across the ocean, can provide an early-warning indicator for highly variable seasonal changes in climate conditions, such as El Niño events.
Observing the Gulf Stream for climate studies seeks information on seasonal to interannual changes in the volume of water and heat transported. Yet the Gulf Stream meanders so much that a single transit can be misleading about long-term average values. Thus, a team of scientists from the University of Rhode Island and the State University of New York have pursued a program that collects repeated transits to construct reliable estimates of long-term statistics.
They installed an ADCP on a merchant ship, CMV Oleander, which makes a regular crossing from New York to Bermuda. Initially using a 150-kilohertz ADCP to sample upper-ocean currents, and later a 75-kilohertz ADCP to profile as deep as 800 meters, their team has maintained the study for 20 years. The collected data set provides a rich resource for examining Gulf Stream variability over a range of time scales and several distinctive oceanic regimes.
Research ships worldwide are now routinely equipped with ADCPs; their spatial sections have proved valuable for viewing the circulation patterns of ocean currents. As well as providing current speeds and volumes for monitoring purposes, these data permit validation and improvement of computer-based models of ocean circulation. These improvements have been particularly relevant for seasonal climate prediction that is influenced by equatorial oceans.
As part of the groundswell to supplement ship-based observations with oceangoing gliders and vehicles, TRDIís ADCPs are being integrated into new platforms. Teledyne Webbís (East Falmouth, Massachusetts) G2 Slocum Glider will include an ADCP that can offer both bottom tracking capability and proven lowered ADCP techniques to extend current measurements through the water column. Similarly, the Wave Glider by Liquid Robotics (Sunnyvale, California), which uses wave motion and solar energy to power an ocean-going platform, houses TRDIís ADCPs.
For the past decade, offshore engineering has seen a tremendous increase in using ADCPs for real-time measurements of ocean currents. These data aid the timing, safety and success of operations like retrieving a blow-out preventer, deploying an ROV or supporting pipelaying operations.
With the trend of extracting oil and gas from deeper seabeds, there is a widespread need to monitor and understand deepwater currents that affect conditions for the drilling riser, particularly with respect to flow-induced vibration. Operators want to be informed about surface currents and waves that threaten navigation, safety and sometimes survival around offshore platforms as well. On the beach, ADCP data have aided the design process for new offshore structures.
Ship-based surveys for seismic exploration have a long history of using ADCPs. The real-time surface current data can provide significant cost savings by avoiding problems due to unexpected changes in current speed and direction. The types of problems range from gaps in survey coverage to damage and tangling of streamers during deployment and recovery or stacking for tight turns.
The remote measurement capability of ADCPs is also proving valuable to companies exploring sites for renewable energy. While mounted on the seabed, ADCPs can collect environmental information in demanding situations farther up the water column, such as fast water currents and well-developed wave fields. This information is used for site selection, environmental monitoring, understanding operational efficiencies of renewable energy devices and verifying models for turbine spacing.
Doppler Velocity Logs and Navigation
In the early 1990s, TRDI introduced a DVL that uses broadband signaling, a key contributor to improving the navigation of underwater vehicles.
For several decades, scientists at the Woods Hole Oceanographic Institution have been operating underwater vehicles at great depths. They were early adopters of TRDIís DVL and have used it successfully for hundreds of missions over rugged terrain, from mapping mid-ocean ridges and subsea volcanoes to discovering hydrothermal vents. Hydroid Inc.ís (Pocasset, Massachusetts) REMUS AUVs also employ TRDIís broadband DVLs. A recent project that stressed DVL navigation over extremely steep terrain was the successful search for the lost Air France flight 447 in the depths of the southwest Atlantic.
Although requests for custom-design DVLs have long been part of TRDIís business, in 2009 the company received its most extreme case: A DVL was required to withstand pressures at 11,000 meters depth because it was to be mounted on Nereus, the hybrid robotic vehicle that explored the Challenger Deep of the Mariana Trench.
ADCPs in Coastal and River Applications
Many innovative applications of the ADCP have been developed. This flexibility stems from inspired combinations of the four different types of measurements made by the device. Outstanding among these was a method to measure directional wave spectra, current profiles and water level at the same time.
In 2002, the power of this method was demonstrated by scientists from Louisiana State University when they recorded waves from hurricanes Lili and Isidore. Lili passed close by their ADCP, and those data demonstrated the significant effects of strong storm surge on the wave field when the hurricane makes landfall—water level virtually switched from 4 meters to 6 meters depth. The ADCP data also provided a unique description of the evolution and rapid directional rotation of the wave field driven by the advancing hurricane.
In 1991, broadband ADCPs enabled a method for gauging the volume of water carried by rivers, providing a safer way to measure flooding rivers. The broadband ADCPs were adopted by the United States Geological Survey and river agencies in Europe, and in the mid-1990s provided the first accurate measurements of the largest river discharge on the planet, the mouth of the Amazon.
Recently, TRDI introduced a new generation of its river ADCP called RiverRay that is a fully-automated system with embedded intelligence that takes care of auto-setup at the riverbank and optimizes measurements continuously as water depth and flow conditions vary.
Partnered with other Teledyne Marine companies, TRDI will continue to expand its products offerings. TRDI is working with Teledyne Webb Research to integrate ADCPs into the coastal G2 Slocum Glider to support the Ocean Observatories Initiative and collaborating with Teledyne Odom Hydrographic Inc. (Baton Rouge, Louisiana) on new sonar products for hydrographic survey instrumentation used in port survey, dredging and offshore energy.
Moving to other adjacent markets, TRDI now has instruments for measuring physical properties of water with its CTD sensor that uses inductive technology, making it less prone to drift from corrosion and able to be cleaned in the field without disrupting calibration.
TRDIís future ties to a consistent theme throughout its 30-year history—advancing high-tech capability for the marine community.