Sound Velocity Profiles, AML Minos X sound velocity profile data, collected during USGS field activity 2017-049-FA within Lake Powell, UT-AZ (PNG images, SVP text, and Esri point shapefile, GCS WGS 84).

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Frequently anticipated questions:


What does this data set describe?

Title:
Sound Velocity Profiles, AML Minos X sound velocity profile data, collected during USGS field activity 2017-049-FA within Lake Powell, UT-AZ (PNG images, SVP text, and Esri point shapefile, GCS WGS 84).
Abstract:
High-resolution geophysical mapping of Lake Powell in the Glen Canyon National Recreation Area in Utah and Arizona was conducted between October 8 and November 15, 2017, as part of a collaborative effort between the U.S. Geological Survey and the Bureau of Reclamation to provide high-quality data needed to reassess the area-capacity tables for the Lake Powell reservoir. Seismic data collected during this survey can help to define the rates of deposition within the San Juan and Colorado Rivers, which are the main inflows to Lake Powell. These new data are intended to improve water budget management decisions that affect the natural and recreational resources of the reservoir. Multibeam echosounder bathymetry and backscatter data were collected along 2,312 kilometers of tracklines (331 square kilometers) of the lake floor to regionally define its depth and morphology, as well as the character and distribution of lake-floor sediments. Ninety-two kilometers of seismic-reflection profile data were also collected to define the thickness and structure of sediment deposits near the confluences of the San Juan and Colorado Rivers.
Supplemental_Information:
Additional information on the field activity is available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-049-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 2018, Sound Velocity Profiles, AML Minos X sound velocity profile data, collected during USGS field activity 2017-049-FA within Lake Powell, UT-AZ (PNG images, SVP text, and Esri point shapefile, GCS WGS 84).: data release DOI:10.5066/P90BU2VS, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D., Baldwin, Wayne E., Worley, Charles R., Baskin, Robert L., Denny, Jane F., Foster, David S., Irwin, Barry J., Moore, Eric M., and Nichols, Alex R., 2018, High-resolution geophysical data collected in Lake Powell Utah-Arizona, U.S. Geological Survey Field Activity 2017-049-FA: data release DOI:10.5066/P90BU2VS, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Andrews, B.D., Baldwin, W.E., Worley, C.R., Baskin, R.L., Denny, J.F., Foster, D.S., Irwin, B.J., Moore, E.M., and Nichols, A.R., 2018, High-resolution geophysical data collected in Lake Powell, Utah-Arizona, U.S. Geological Survey Field Activity 2017-049-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P90BU2VS.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -111.482500
    East_Bounding_Coordinate: -110.431667
    North_Bounding_Coordinate: 37.835278
    South_Bounding_Coordinate: 36.986667
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5b97ca9ce4b0702d0e841ef3/?name=2017-049-FA_SVPdata_browse.jpg (JPEG)
    Thumbnail image of sound speed profile locations collected within Lake Powell, UT-AZ.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 08-Oct-2017
    Ending_Date: 15-Nov-2017
    Currentness_Reference:
    data were collected on the following dates: 20171008-20171022 (Julian day 281-295); 20171024-20171109 (Julian day 297-313); 20171115 (Julian day (319).
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a vector data set. It contains the following vector data types (SDTS terminology):
      • point (56)
    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 D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    2017-049-FA_SVPdata
    Sound velocity profile locations for survey 2017-004-FA collected within Lake Powell, UT-AZ. (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    Lon
    Decimal degree longitude value in GCS WGS 84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-111.482500
    Maximum:-110.431667
    Units:degrees
    Resolution:.000001
    Lat
    Decimal degree latitude value in GCS WGS 84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:36.986667
    Maximum:37.835278
    Units:degrees
    Resolution:.000001
    SVP
    Name of velocity profile used to distinguish between casts. Profiles are named by the Date and UTC time of the profile collection in the format YYYY-MM-DD_HH-MM-SS. (Source: U.S. Geological Survey) character set
    Date
    Month/day/year when the SVP cast was collected. (Source: U.S. Geological Survey) character set
    JD_UTC
    Julian day and UTC time when the SVP cast was collected in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. (Source: U.S. Geological Survey) character set
    SurveyID
    WHCMSC field activity identifier (e.g. "2017-049-FA" where 2017 is the survey year, 049 is survey number of that year, and FA is field activity). (Source: U.S. Geological Survey) character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) character set
    DeviceID
    Device used to collect sound speed profile data. (Source: U.S. Geological Survey) character set
    SVP_Image
    Name of the PNG image file associated with the SVP cast. (Source: U.S. Geological Survey) Character set
    Entity_and_Attribute_Overview:
    The PNG images can be hyperlinked to their shapefile location in ArcGIS. The graphs show depth in meters below the water suface on the y-axis and speed of sound in meters per second on the x-axis. In addition to the graphs, the ASCII data is also available in SVP files. The format of the SVP ASCII files is as follows:
    Header row 1: Caris SVP format version number Header row 2: SVP file name Header row 3: Section heading for the profile, containing: The year and Julian day number (YYYY-DDD) the profile was recorded, the UTC time (HH:MM:SS) the profile was recorded, and latitude and longitude coordinates for the profile position in degrees, minutes, seconds format (DD:MM:SS).
    Remaining rows: column data of depth (meters) and speed of sound (meters per second) space delimited.
    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)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Brian Andrews
    Geographer
    384 Woods Hole Road
    Woods Hole, Massachusetts
    US

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

This dataset is used to display the locations of sound velocity profiles (SVP, also referred to as sound speed profiles), as well as the SVP data, collected during a 2017 USGS survey on Lake Powell in the Glen Canyon National Recreation Area of Utah and Arizona. The sound velocity profiles document water column sound speed variability during the survey, and were used during processing to account for refraction artifacts present within the multibeam bathymetric data. The dataset contains graphs of sound velocity vs. depth at each profile location, as well as a shapefile with the location in Geographic Coordinate System (GCS) WGS 84 latitude and longitude, the time of day, and date of collection.

How was the data set created?

  1. From what previous works were the data drawn?
    raw sound velocity data (source 1 of 1)
    U.S. Geological Survey, unpublished material, sound velocity data.

    Type_of_Source_Media: disc
    Source_Contribution:
    Sound velocity profiles were collected using an AML Minos X SVPT deployed using an electric downrigger mounted on the port quarter of the R/V Stephens. The clutch on the downrigger was released to allow for free fall deployment of the instrument to the user defined depth above the lake floor, followed by motorized retrieval. Three AML Oceanographic XChange probes attached to the Minos X body logged sound velocity, pressure, and temperature data during each deployment. AML SeaCast software(v. 4.4) was used to read the profile data from the Minos X, edit the profile to preserve only the downcast portion of the deployment, and export the profile Caris .svp ASCII formatted files. DGPS navigation data for the sound velocity profiles were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5) with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented fore and aft and mounted atop the MBES pole, approximately midships on the starboard side of the vessel. A Hypack (v. 17.0.26.0) target was created to record the position of each SVP station, and the geographic coordinates were manually entered into the headers of the final Hypack .vel and Caris .svp formatted ASCII files.
  2. How were the data generated, processed, and modified?
    Date: Nov-2017 (process 1 of 4)
    PROCESS STEP 1: SVP profile acquisition during survey:
    Sound velocity profiles were collected one to three times per survey day using the AML Minos X SVPT.
    This process step and all subsequent process steps were conducted by the same person - Wayne Baldwin. Person who carried out this activity:
    Wayne E. Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: Nov-2017 (process 2 of 4)
    PROCESS STEP 2: Plot the SVP data and import into Spatialite database:
    A python script was used to read the SVP data and plot the sound speed profile as speed of sound (meter/second) versus depth (meters). Position, date, time, and profile id were pulled from the SVP header and written into the image (PNG) for reference. Within the same script, the position, Julian day, time, and profile id were also imported into a Spatialite (version 4.3.0) enabled SQLite (version 3.21.0) database table. The geographic positions were used to create point geometries for the station locations, and additional fields indicating SurveyID, VesselID, DeviceID, and SVP_Image were added.
    Date: Nov-2017 (process 3 of 4)
    PROCESS STEP 3: Create Esri shapefile containing the point data:
    The SVP point features were added (Add Data) into ArcMap (version 10.3.1) from the SQLite database, then exported (Right click on database feature class >Data>Export Data) to the new Esri point shapefile 2017-049-FA_SVPdata.shp.
    Date: 06-Aug-2020 (process 4 of 4)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  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?
  2. How accurate are the geographic locations?
    DGPS navigation data for the sound velocity profiles were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5) with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented fore and aft and mounted atop the MBES pole, approximately midships on the starboard side of the vessel. A Hypack (v. 17.0.26.0) target was created to record the position of each SVP station, and the geographic coordinates were manually entered into the headers of the final Hypack .vel and Caris .svp formatted ASCII files. While the horizontal position accuracy is thought to be within 0.5 - 2 meters for the DGPS position solutions, we consider the sound velocity profile positions to be within 2-4 m, since the location of downrigger used to deploy the SVP relative to the MBES pole, approximately 1.5 meters aft, was not accounted for.
  3. How accurate are the heights or depths?
    Minos X SVPT depths are calculated by the AML SeaCast software(v. 4.4), which converts pressure sensor readings to depth using the standard formulas described in Fofonoff, N.P.and Millard, R.C., Jr., 1988, Algorithms for computation of fundamental properties of seawater, UNESCO Technical Papers in Marine Science, No. 44. The depths are thought to be accurate to within 1 meter.
  4. Where are the gaps in the data? What is missing?
    Each sound velocity profile (56 total) collected during survey 2017-049-FA is represented by an SVP formatted ASCII text file (see description below in the entity and attribute overview section), a PNG image file, and a feature point location in the Esri shapefile. Profile 2017-10-12_15-33-12 was faulty and excluded during QA/QC processing.
  5. How consistent are the relationships among the observations, including topology?
    Sound velocity profiles were acquired with an AML Minos X SVPT from 2017108–20171022 (JD281–295) and 20171024 to 20171115 (JD 297-319). No data were collected on 20171023 (JD 296) while the base of operations was moved from Bullfrog, UT in the northeast to Page, AZ in the southwest. No sound speed profiles were collected between 20171110 and 20171114 (JD 314-318) while survey operations were suspended due to equipment malfunction. These data only contain the downcast data collection.

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:
Public domain data from the U.S. Government are freely re-distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2017-049-FA AML Minos X SVP data from Lake Powell, UT-AZ: includes the shapefile 2017-049-FA_SVPdata.shp, the zip archive 2017-0049-FA_SVP_Images.zip containing 56 PNG images that represent all sound velocity profiles graphically, the zip archive 2017-049-FA_SVP_ASCII.zip containing 56 SVP ASCII files that represent all sound velocity profiles, the browse graphic 2017-049-FA_SVPdata_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2017-049-FA_SVPdata_meta.*) in XML, HTML, FAQ, and text formats.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    For the shapefile and web services data, the user must have software capable of reading shapefile format, or GIS software capable of utilizing web mapping or feature services. The ASCII SVP files can be read with a text editor. PNG files can be viewed with any PNG image viewing software. The Zip files must be uncompressed to utilize the ASCII text files or view the images.

Who wrote the metadata?

Dates:
Last modified: 06-Aug-2020
Metadata author:
Wayne E. Baldwin
U.S. Geological Survey
Geologist
384 Woods Hole Rd.
Woods Hole, MA

(508) 548-8700 x2226 (voice)
(508) 457-2310 (FAX)
wbaldwin@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P90BU2VS/2017-049-FA_SVPdata_meta.faq.html>
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