Vessel-mounted acoustic Doppler current profiler (ADCP) data from the lower Columbia River, Washington and Oregon, 2021

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Frequently anticipated questions:

What does this data set describe?

Title:
Vessel-mounted acoustic Doppler current profiler (ADCP) data from the lower Columbia River, Washington and Oregon, 2021
Abstract:
This dataset contains water velocity data derived from spatial surveys performed with a vessel-mounted acoustic Doppler current profiler at four sites (SKM, SLG, LDB, WLW) in the lower Columbia River, Washington and Oregon, in 2021. The data are provided in netCDF (.nc) format and compressed into .zip archives for each site.
Supplemental_Information:
Additional information about the field activity or activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-621-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. How might this data set be cited?
    Stevens, Andrew W., Hatcher, Gerald A., Ferro, Peter Dal, Dartnell, Peter, Warrick, Jonathan A., Cohn, Nicholas, and Moritz, Hans R., 20230808, Vessel-mounted acoustic Doppler current profiler (ADCP) data from the lower Columbia River, Washington and Oregon, 2021: data release DOI:10.5066/10.5066/P92U1KPY, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Stevens, Andrew W., Hatcher, Gerald A., Ferro, Peter Dal, Dartnell, Peter, Warrick, Jonathan A., Cohn, Nicholas, and Moritz, Hans R., 2023, Digital seafloor images, sediment grain size, bathymetry, and water velocity data from the lower Columbia River, Washington and Oregon, 2021: data release DOI:10.5066/P92U1KPY, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    Other_Citation_Details:
    Suggested Citation: Suggested Citation: Stevens, A.W., Hatcher, G.A., Dal Ferro, P., Warrick, J.A., Cohn, N., and Moritz, H.R., 2023, Digital seafloor images, sediment grain size, bathymetry, and water velocity data from the lower Columbia River, Washington and Oregon, 2021: U.S. Geological Survey data release, https://doi.org/10.5066/P92U1KPY.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -123.441836
    East_Bounding_Coordinate: -122.760616
    North_Bounding_Coordinate: 46.249934
    South_Bounding_Coordinate: 45.712744
  3. What does it look like?
    vmadcp_example.png (PNG)
    Map showing magnitude and direction of depth-averaged currents and cross-sections showing profiles of current speed and direction
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 05-Jun-2021
    Ending_Date: 09-Jun-2021
    Currentness_Reference:
    ground condition at time data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: comma-delimited text
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference:
      Data were collected continuously along survey transects. Refer to self-contained NetCDF files for more location information.
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    NetCDF files are self-contained and attribute information may be found in the header of the file itself.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Andrew W. Stevens
    • Gerald A. Hatcher
    • Peter Dal Ferro
    • Peter Dartnell
    • Jonathan A. Warrick
    • Nicholas Cohn
    • Hans R. Moritz
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Attn: PCMSC Science Data Coordinator
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

Growth of subaqueous sand dunes commonly causes shoaling in engineered river channels that necessitates costly dredging to maintain adequate depths for navigation. The factors that result in sand wave growth are theoretically understood from laboratory experiments, but the capacity to predict sand wave geometries in field settings is limited due to temporal and spatial variability in hydrodynamics and sediment grain size. Detailed measurements of sand wave geometries, hydrodynamics, and grain size are therefore needed to test and improve numerical models and inform efficient management strategies in navigation channels. This data release presents surface sediment grain size distributions, bathymetry and seafloor acoustic backscatter, and water velocity data acquired at four sites with subaqueous sand dunes in the lower Columbia River, Washington and Oregon, between June 4 and June 9, 2021. The four sites were located between 65 km and 127 km upstream from the ocean inlet along a gradient of relative tidal and fluvial influence. The survey was performed during peak annual river discharge when sediment transport processes were likely active. High resolution digital images were collected at each site with an underwater camera system that was repeatedly lowered to the seabed along a series of 1 km-long transects oriented along the main navigation channel and spaced about 60 m apart. The grain size distributions of the seabed images were estimated using an automated image processing technique and tested with observed grain size distributions derived from manual measurements on a subset of 16 images. Swath bathymetry and seafloor acoustic backscatter data were collected repeatedly at each site using a 234.5 kHz phase-differencing sidescan sonar to characterize sand wave geometry and bathymetric change resulting from sand wave migration. Current velocity data were collected from an underway survey vessel equipped with a downward looking 600 kHz ADCP along transects oriented both along- and across the main navigation channel. Combined, these data provide a comprehensive characterization of mobile subaqueous sand dunes that can be used to improve predictions of dune growth in complicated field settings and inform efficient sediment management practices in the lower Columbia River.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 09-Jun-2021 (process 1 of 3)
    Water velocity data were acquired at four sites with a vessel-mounted acoustic doppler current profiler (ADCP) in the lower Columbia River between June 5 and June 9, 2021. Measurements of current velocity in the water column were collected using a downward looking 600 kHz Teledyne RDI ADCP pole-mounted to the R/V Park Snavely as the vessel surveyed tracklines oriented along and across the main navigation channel. Positioning and orientation of the ADCP were measured using an Applanix POS MV 320 and recorded at 1 Hz intervals. Data acquisition and merging of the ADCP and positioning data were achieved with Teledyne RDI VMDAS software. While underway, profiles of current velocity and acoustic backscatter data were collected from 1.48 m below the transducer (approximately 2.2 m below the water surface) to the seafloor at 0.5 m intervals. Raw ADCP data were transformed to Earth coordinates in real time using heading and tilt information supplied by the POS MV. Velocity measurements were corrected to remove the motion of the vessel using the navigation data recorded by the POS MV because the bed was assumed to be mobile during the surveys.
    Date: 24-Mar-2023 (process 2 of 3)
    Raw ADCP data were reprocessed to remove heading bias due to imprecise mounting of the instrument on the survey vessel. A heading bias correction of 8 degrees was applied to all data collected during the survey using Teledyne RDI VMDAS software.
    Date: 19-May-2023 (process 3 of 3)
    Data were accumulated into NetCDF files for distribution
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    No formal attribute accuracy tests were conducted.
  2. How accurate are the geographic locations?
    Positioning of the water velocity measurements were achieved with an Applanix POSMV Wavemaster operating in DGNSS mode. Manufacturer reported accuracy of the horizontal positions while operating in DGNSS mode is between 0.5 and 2 m depending on the quality of the DGNSS corrections received (https://www.applanix.com/downloads/products/specs/posmv/POS-MV-WaveMaster-II.pdf).
  3. How accurate are the heights or depths?
    Depths reported in the data files are relative to the elevation of the ADCP at the time of data collection. Vertical information in this dataset is not associated with any established vertical datum.
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    Data fall within expected ranges.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints None
Use_Constraints USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - CMGDS
    2885 Mission Street
    Santa Cruz, CA

    1-831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? The current velocity data are provided in NetCDF format. The data from each site (site identifiers = SKM, SLG, LDB, WLW) are provided in separate compressed (.zip) files. The support file, vmadcp_file_list.csv, contains a list of files, data collection times, and orientations of transects contained in each zip archive.
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Zip file contains vessel-mounted ADCP data from the LDB Site in NetCDF format in format NetCDF (version MATLAB Version: 9.13.0.2080170 (R2022b)) Size: 0.724
      Network links: https://doi.org/10.5066/P92U1KPY
      Data format: Zip file contains vessel-mounted ADCP data from the SKM Site in NetCDF format in format NetCDF (version MATLAB Version: 9.13.0.2080170 (R2022b)) Size: 0.471
      Network links: https://doi.org/10.5066/P92U1KPY
      Data format: Zip file contains vessel-mounted ADCP data from the SLG Site in NetCDF format in format NetCDF (version MATLAB Version: 9.13.0.2080170 (R2022b)) Size: 0.586
      Network links: https://doi.org/10.5066/P92U1KPY
      Data format: Zip file contains vessel-mounted ADCP data from the WLW Site in NetCDF format in format NetCDF (version MATLAB Version: 9.13.0.2080170 (R2022b)) Size: 0.379
      Network links: https://doi.org/10.5066/P92U1KPY
    • Cost to order the data: None.

Who wrote the metadata?

Dates:
Last modified: 08-Aug-2023
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/CMGDS_DR_tool/DR_P92U1KPY/vmadcp_metadata.faq.html>
Generated by mp version 2.9.51 on Fri Aug 18 09:04:49 2023