Digital seafloor images and sediment grain size from the mouth of the Columbia River, Oregon and Washington, 2014

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:


What does this data set describe?

Title:
Digital seafloor images and sediment grain size from the mouth of the Columbia River, Oregon and Washington, 2014
Abstract:
This dataset includes 2,523 still images extracted from geo-referenced digital video imagery of the seafloor at the mouth of the Columbia River, OR and WA, USA, along with grain size analysis of the surface sediment. Underwater digital video was collected in September 2014 in the mouth of the Columbia River, USA, as part of the U.S. Geological Survey Coastal and Marine Geology Program contribution to the Office of Naval Research funded River and Inlets Dynamics experiment (RIVET II). Still images were extracted from the underwater video footage whenever the camera was resting on the sediment bed and individual sediment grains were visible and in focus. The images are used to calculate the median grain size through an auto-correlation method (Barnard and other 2007), and are provided in an accompanying .csv file.
Supplemental_Information:
Information about the data collection field activities can be found at: http://cmgds.marine.usgs.gov/fan_info.php?fan=2014-642-FA
  1. How might this data set be cited?
    Gelfenbaum, Guy R., Carlson, Emily M., Stevens, Andrew W., and Rubin, Dave M., 2017, Digital seafloor images and sediment grain size from the mouth of the Columbia River, Oregon and Washington, 2014: data release DOI:10.5066/F7K64G8V, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -124.07033
    East_Bounding_Coordinate: -123.91990
    North_Bounding_Coordinate: 46.25511
    South_Bounding_Coordinate: 46.21357
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 11-Sep-2014
    Ending_Date: 13-Sep-2014
    Currentness_Reference:
    ground condition at time data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector Digital Data Set (Point)
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (2523)
    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 1.0E-6. Longitudes are given to the nearest 1.0E-6. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS1984.
      The ellipsoid used is WGS1984.
      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?
    Attribute Table
    Table containing attribute information associated with the data set. (Source: Producer defined)
    IMAGE_NAME
    Filename of extracted still-image (Source: Red Hen Systems) Unique identifier for each still image
    TIME
    Julian dates (abbreviated JD) are a continuous count of days and fractions since noon Universal Time on January 1, 4713 BC (on the Julian calendar). (Source: "http://aa.usno.navy.mil/data/docs/JulianDate.php")
    Range of values
    Minimum:2456913.7848206
    Maximum:2456915.97975694
    D50
    Particle diameter representing the 50% cumulative percentile value (50% of the particles in the sediment sample are finer than the D50 grain size), in mm. (Source: "https://pubs.usgs.gov/ds/0834/data/Metadata/Tables_metadata/Cat_Island_grainsize_data%20dictionary.pdf")
    Range of values
    Minimum:0.18
    Maximum:0.936
    LAT
    Geographic latitude in decimal degrees WGS84, south longitudes negative (Source: ESRI "http://support.esri.com/en/knowledgebase/gisdictionary/term/longitude)
    Range of values
    Minimum:46.2135775089276
    Maximum:46.2551170826057
    LON
    Geographic longitude in decimal degrees WGS84, west longitudes negative (Source: ESRI "http://support.esri.com/en/knowledgebase/gisdictionary/term/longitude)
    Range of values
    Minimum:-124.070332272848
    Maximum:-123.919901148423
    EASTING
    The distance east of the origin that a point in a Cartesian coordinate system lies, measured in that system's units. (Source: ESRI "http://support.esri.com/other-resources/gis-dictionary/search/easting")
    Range of values
    Minimum:417497.36650791
    Maximum:429076.526080222
    NORTHING
    The distance north of the origin that a point in a Cartesian coordinate system lies, measured in that system's units. (Source: ESRI "http://support.esri.com/en/knowledgebase/gisdictionary/term/northing")
    Range of values
    Minimum:5118216.10628444
    Maximum:5122869.35747645
    Entity_and_Attribute_Overview:
    The entity and attribute information provided here describes the tabular data associated with the images in the dataset. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information was generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Guy R. Gelfenbaum
    • Emily M. Carlson
    • Andrew W. Stevens
    • Dave M. Rubin
  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: Andrew W. Stevens
    Oceanographer
    2885 Mission Street
    Santa Cruz, CA
    USA

    831-460-7540 (voice)
    astevens@usgs.gov

Why was the data set created?

The imagery was collected to obtain high spatial resolution grain size data over individual subaqueous bedforms.

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: 12-Jun-2015 (process 1 of 6)
    Video footage was converted from video type .MXF to a Red Hen System compatable format of .AVI using the software Acrok MXF Converter. All image and sound quality were maintained at the original video's quality.
    Date: 12-Jun-2015 (process 2 of 6)
    Video footage was indexed using Red Hen System's proprietary software IsWhere. An XML format metadata file was produced from each video and includes GPS information intermittently through the video of: latitude (decimal degrees), longitude (decimal degrees), GPS altitude (meters), video time (HH:mm:ss:ms), Dublin Julian Date in UTC (julian date = timeCode+2415020), course direction (degrees), speed (meters/second).
    Date: 12-Jun-2015 (process 3 of 6)
    Geotagged images were grabbed from the video every 0.5 second. From this set of evenly timed images, images were chosen when the sediment bed was in focus and the camera was resting on the bed. This process resulted in there being multiple images for each location. The image files contain the GPS location in lat/lon decimal degrees.
    Date: 12-Jun-2015 (process 4 of 6)
    Each image is given a file name based on the video it was taken from, followed by the time stamp in the video. For example image "0205301_0_1_41_0" is from video 0205301 at time 00:01:41:00 (HH:mm:ss:ms).
    Date: 12-Jun-2015 (process 5 of 6)
    The UTC time of each image was calculated by extracting the UTC time at the beginning of the video from the XML file produced by IsWhere for each video file, and adding the time stamp of the image. These values are recorded in Julian time in the UTC time zone in the provided spreadsheet. The lat/lon values were converted to UTM zone 10N, WGS84 coordinates using the matlab tool "deg2utm" version Aug/06, available at mathworks.com, and recorded in the provided spreadsheet.
    Date: 12-Jun-2015 (process 6 of 6)
    The median grain size of sediment shown in each image was estimated using an auto-correlation process and calibration images, which are available in "child-item title", included with this publication.
  3. What similar or related data should the user be aware of?
    Barnard, P.L., Rubin, D.M., Harney, J., and Mustin, N., 2007, Field test comparison of an auto-correlation technique for determining grain size using a digital ‘beachball’ camera versus traditional methods.

    Online Links:

    Gelfenbaum, G., Finlayson, D., Dartnell, P., Carlson, E., and Stevens, A., 2015, Bathymetry and backscatter from 2013 interferometric swath bathymetry systems survey of Columbia River Mouth, Oregon and Washington.

    Online Links:


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

  1. How well have the observations been checked?
    Accuracy of dataset attribute information was deduced to be good based both on visual examination of still images, video imagery, navigation trackline location on agreement with observer's field knowledge.
  2. How accurate are the geographic locations?
    The positions of the data reflect the position of the GPS antenna on board the boat when data were collected and not the real location of the camera in the water. Positional data in this report were not corrected for layback and thus represent only approximate locations.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the dataset was not been conducted, nor is it applicable.
  4. Where are the gaps in the data? What is missing?
    Data represent ground conditions of the mouth of the Columbia River only along individual tracklines where data were collected.
  5. How consistent are the relationships among the observations, including topology?
    Data are logically accurate

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. Use of appropriate byline/photo/image credit is requested; Suggested credit: Photo by USGS (or U.S. Geological Survey, depending on audience).
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - Science Base
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? Digital seafloor images in JPEG format (MCR14_SeafloorSediment_Images.zip) and a table in comma-delimited format containing location and grain size data (MCR14_SeafloorSediment_Grainsize.csv) are available for download, along with CSDGM FGDC-compliant metadata (MCR14_SeafloorSediment_metadata.xml)
  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?
  5. What hardware or software do I need in order to use the data set?
    To utilize these data, the user must have software capable of uncompressing the zip file, viewing JPEG images, and reading spreadsheets.

Who wrote the metadata?

Dates:
Last modified: 23-Mar-2017
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: Andrew W. Stevens
Oceanographer
2885 Mission Street
Santa Cruz, CA

831-460-7540 (voice)
astevens@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/MCR14_SeafloorSediment_metadata.faq.html>
Generated by mp version 2.9.49 on Mon Sep 10 17:43:23 2018