Current measurements from acoustic doppler current profilers (ADCP) in the southwest Atlantic Ocean from the World Ocean Circulation Experiment (WOCE) from 1991-01-03 to 1992-11-26 (NCEI Accession 0087597)


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            title:  Current measurements from acoustic doppler current profilers (ADCP) in the southwest Atlantic Ocean from the World Ocean Circulation Experiment (WOCE) from 1991-01-03 to 1992-11-26 (NCEI Accession 0087597)
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                date:  2015-03-04
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                  Anchor:  https://www.nodc.noaa.gov/cgi-bin/OAS/prd/person/details/2455 Thomas Muller
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        abstract:  Current meter data from the ADCP instruments of BE/335 and BW/333 from January 3, 1991 to November 26, 1992 collected as part of the World Ocean Circulation Experiment (WOCE).
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            otherConstraints:  Cite as: Muller, Thomas; Research Center for Marine Geosciences (GEOMAR) (2015). Current measurements from acoustic doppler current profilers (ADCP) in the southwest Atlantic Ocean from the World Ocean Circulation Experiment (WOCE) from 1991-01-03 to 1992-11-26 (NCEI Accession 0087597). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0087597. Accessed [date].
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                    beginPosition:  1991-01-03
                    endPosition:  1992-11-26
        supplementalInformation:  These data are part of the World Ocean Circulation Experiment (WOCE) ADCP observing programme in the Brasil Current study area. These data are not included on the WOCE CD-ROM or DVD-ROM products nor are they presently available via the WOCE online data delivery system. Additional information about these data are available in Tarbell, et al, (IfM-Kiel rep. 243, WHOI rep. 94-07).
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                description:  NCEI Accession 0087597 v1.1 was published.
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                other:  NOAA National Centers for Environmental Information
        lineage:  (LI_Lineage)
            processStep:  (LE_ProcessStep)
                description:  NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
                dateTime:
                  DateTime:  2015-04-22T00:00:00
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    metadataMaintenance:  (MD_MaintenanceInformation)
        maintenanceAndUpdateFrequency:  (MD_MaintenanceFrequencyCode) asNeeded
        maintenanceNote:  Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness.
        contact:  (CI_ResponsibleParty)
            organisationName:  NOAA National Centers for Environmental Information
            role:  (CI_RoleCode) custodian
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    acquisitionInformation:  (MI_AcquisitionInformation)
        instrument:  (MI_Instrument)
            identifier:  (MD_Identifier)
                code:  ADCP
            type:  ADCP
            description:  Acoustic Doppler Current Profiler The Acoustic Doppler Current Profiler (ADCP) measures currents beneath a ship while underway. Sound signals sent from the moving ship bounce back to receivers aboard the ship. This provides a profile of water movement relative to the ship-precise modern navigation, allowing the ship's motion to be subtracted from the data. These devices are also used on moorings and profilers and, along with acoustic backscattering, measure animal biomass. Particles in the path of the sound waves, mostly plankton, reflect a small part of the sound energy back toward receivers, allowing researchers to make remote estimates of the sizes and numbers of animals present in the water column. Before the 1970's, the most technologically advanced instrument used to measure water velocity was known as a Doppler speed log. This evolved into the first commercial ADCP, produced in the mid-1970's, which used averaging. Later in the 1970's, the first vessel-mounted ADCP was developed to measure water velocity more accurately and to allow measurement in range cells over a depth profile. As instruments evolved, so did new techniques in Doppler signal processing. Initially, Doppler speed logs used simple analog signal processing methods, which are still used in some commercial speed logs today. However, the first ADCPs incorporated analog-to-digital signal conversion over a narrow communication bandwidth. Around 1990, this technique was developed into broadband signal processing. Since then, broadband ADCPs have been able to generate very accurate, real-time velocity measurements.