What is an ADCP?
An Acoustic Doppler Current Profiler (ADCP) is a type of sonar that measures and records water current velocities over a range of depths. Teledyne RD Instruments actually designed and delivered the industry’s first ADCP in 1982. The ADCP is now considered an essential tool for oceanography, estuary, river, and stream flow current measurement worldwide.
How do they work?
An ADCP transmits sound bursts into the water column. Suspended particles carried by water currents produce echoes (from these sound bursts) which are “heard” by the ADCP. Echoes arriving later, from deeper in the water column, are assigned greater depths in the echo record. This allows the ADCP to form vertical profiles of current velocity. The ADCP senses in four orthogonal directions simultaneously. Particles within the current flow moving towards the instrument exhibit different frequencies from those moving away. This is the famous Doppler shift, which enables precise measurement of current speed and direction.
What do they do?
When the ADCP is mounted in a moving vessel, the information obtained is used to measure water current speed, vessel speed and direction, and also distance above the sea bed. The ADCP also shows the distribution of suspended material. When the ADCP is mounted on the seabed to look upwards it measures current velocity and direction and with a simple software add-on the direction of waves. So with a Teledyne RDI ADCP you can:
•Survey the patterns of currents, suspended sediments, and zooplankton.
•Simplify difficult measurements—e.g. river discharge and biomass.
•Receive rapidly updated hi-res data in shallow water and observe short-lived events or small sized features.
•Measure vessel movement through water or over the bottom.
•Determine position and altitude of underwater vehicles such as AUVs and ROVs.
•Collect high-resolution time series of currents at many depths using a single instrument.
What makes Teledyne RDI’s ADCPs unique?
With well over 10,000 Doppler products delivered worldwide, Teledyne RDI’s Workhorse ADCP products have become the de facto standard instrument used worldwide by scientists and field engineers to improve their understanding of water current circulation. Only Teledyne RDI’s proven ADCP products can provide:
•BroadBand processing for significantly improved data quality, power efficiency, and error detection over competing narrowband systems.
•2-dimensional phased array transducer design for significantly reduced size, weight, and deployment complexity.
•4-beam configuration designed to ensure data redundancy for quality and reliability.
•A highly flexible design, which ensures that your base instrument is designed to meet your current needs and future needs as well. Teledyne RDI’s ADCPs have become synonymous with high-quality data, ease of operation, and unsurpassed value. Each and every one of our products is backed by:
•Teledyne RDI ADCPs are versatile enough to be used in a wide range of marine applications.
How is my data displayed ?
Teledyne RDI offers an array of software suites designed to quickly convert data into a variety of graphical display options, allowing you to quickly and easily view and assess the data you’ve collected. Versatile software packages allow you to study the results of long-term self-contained deployments, or watch your real-time measurements as they unfold. For those new to data collection, Teledyne RDI’s software offers Wizards that quickly walk you through your system setup and data collection functions. For those with advanced or highly specific data requirements,Teledyne RDI offers the most comprehensive and powerful ADCP software in the industry. From rivers to deep-ocean projects, Teledyne RDI has a software solution to meet your project needs. Top right: ADCP data from New York Harbor showing sheer going out of the harbor at the surface and into the harbor at the bottom. Above right: The east-west velocity field as measured by a 38 kHz Ocean Surveyor mounted on the JAMSTEC R/V Kaiyo, which was steaming at 13 kts off the coast of Mindanao (Philippines). The x axis is ensemble number (five minutes per ensemble), the y axis is range in meters and the velocity range is indicated by the color bar at the top of the plot. Note the deep, strong eddy centered at 1,000 m depth. Teledyne RD Instruments, Inc. specializes in the design and manufacture of underwater acoustic Doppler products for a wide array of current-profiling and precision navigation applications.
Where is an ADCP used ?
Offshore Energy Applications:
1. Oil & Gas:
Long range current profiles and wave measurement in support of deepwater oil and gas exploration, drilling and production. Real-time current measurement for decision making during drilling, riser deployment & recovery and ROV operations. Full water column current profiles to detect VIM phenomenon and help model VIV. Seismic, Cable and Pipe Laying Vessel Operations: Real-time current profiles for streamer cable feathering angle prediction and correction, pipe lay and cable lay operations to calculate accurate touchdown position, ROV operations.
2. Renewable Energy
Tidal/Wave/Offshore Wind, Current and wave measurement for site selection, design and performance monitoring, and environmental impact studies.
Coastal Applications:
3. Biological Oceanographic
Wave and current measurements for oceanographic/meteorological data collection, display/analysis to quantify the biological/ ecological condition of coasts and estuaries.
Environmental Management: Oceanographic and meteorological data collection, display/analysis to properly manage coastal development and quantify the environmental effects of development and conduct environmental impact studies.
4. Fisheries/Aquaculture
Current and wave data for site assessment and short or long-term environmental monitoring.
5. Navigation Safety
Current and wave measurements for oceanographic/meteorological data collection, display/analysis to increase the safety of vessel navigation within or approaching a terrestrial port.
6. Coastal and Ocean Engineering
Academic Coastal Oceanography: Current and wave measurements for research areas including near-shore circulation, tidal currents, meso/micro scale turbulence, waves and wave current interaction.
Oceanographic Applications:
7. Integrated Ocean Observation Systems (IOOS) and Ocean Observatory Initiatives (OOI)
Real-time current and wave data support the integrated long-term monitoring, predicting and modeling of ocean environments with time scales ranging from minutes to decades.
8. Deep and Mid-Water Depth Moorings
Moored ADCPs for oceanographic research based on the measurement of seasonal, annual, and decadal variability of ocean currents.
9. Oceanographic Research Vessels
Large-scale, detailed measurements of ocean currents and motility of entrained biomass populations using vessel-mounted ADCPs. Current and wave measurements for oceanographic/meteoro.
10. Autonomous Underwater Vehicles (AUVs) and Gliders logical data collection
Display/analysis to properly design coastal ADCPs installed onboard AUVs and gliders collect current structures and public works projects, provide long-term monitor-profile data over an extended range and duration for academic, and assess impact to the littoral environment. commercial, and military applications.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment