Multibeam line files from Cross Sound, Alaska collected during USGS field activity 2015-629-FA

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Frequently anticipated questions:

What does this data set describe?

Title:
Multibeam line files from Cross Sound, Alaska collected during USGS field activity 2015-629-FA
Abstract:
Processed Reson 7111 multibeam line files from a May 2015 survey offshore Cross Sound, southeast Alaska. Data were collected and processed by the U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number 2015-629-FA. Data are provided as generic sensor format (GSF) line files.
Supplemental_Information:
Additional information about the field activities from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-629-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the dataset in nonproprietary form, as well as in a number of multibeam echosounder processing software, this metadata file may include some multibeam echosounder processing software-specific terminology.
  1. How might this data set be cited?
    Dartnell, Peter, Brothers, Daniel S., Haeussler, Peter J., Hatcher, Gerry A., and Wyland, Robert M., 20250412, Multibeam line files from Cross Sound, Alaska collected during USGS field activity 2015-629-FA: data release DOI:10.5066/P1ED3GXB, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    Other_Citation_Details:
    Suggested Citation: Dartnell, P., Brothers, D.S., Haeussler, P.J., Hatcher, G.A., Wyland, R., 2025, Multibeam line files from Cross Sound, Alaska collected during USGS field activity 2015-629-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P1ED3GXB.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -137.202
    East_Bounding_Coordinate: -136.217
    North_Bounding_Coordinate: 58.426
    South_Bounding_Coordinate: 57.808
  3. What does it look like?
    2015-629-FA_GSF_Files_QV.jpg (JPEG)
    Preview image of 2015 Cross Sound GSF tracklines
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 05-May-2015
    Ending_Date: 21-May-2015
    Currentness_Reference:
    ground condition at time data were collected.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: GSF
  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):
      • String (504)
    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 WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 0.01
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    These data are organized into separate zip files based on the date of collection (Julian day). Within each Julian day folder, there are Generic Senso Format (GSF) files labeled in the format "year_month_day_line_number_shipname". Additionally, these data are supplemented by files used for bathymetric processing. The data release support file section has sound velocity profiles as a single file (2015-629-FA_ALL_SVP.svp) with geographic locations, times, and sound velocities relative to depth in Caris HIPS and SIPS format. The support file section has the survey vessel file in Caris HIPS and SIPS format (ADFG_Solstice.hvf) that includes the vessel lever arm offsets and multibeam calibration corrections. The support file section has a verified tide table used in post-processing that includes data, time, and verified tide in Caris HIPS and SIPS format. The GSF files should have all this information applied but the files are included in the data release for completion.
    Entity_and_Attribute_Detail_Citation:
    files were exported from Teledyne Geospatial Caris HIPS and SIPS software (version 9) and have entity and attributes as published at https://www.ldeo.columbia.edu/res/pi/MB-System/mbweb/tmp/formatdoc/gsf_spec.pdf.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Peter Dartnell
    • Daniel S. Brothers
    • Peter J. Haeussler
    • Gerry A. Hatcher
    • Robert M. Wyland
  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?

In 2015 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) in cooperation with the Alaska Department of Fish and Game (ADFG) collected bathymetry and acoustic backscatter data offshore Cross Sound in southeast Alaska using an Reson 7111 multibeam echosounder mounded to the ADFG R/V Solstice. The survey was conducted to map the offshore expression of the Queen Charlotte fault system that runs for approximately 500 kilometers off the coast of southeast Alaska and British Columbia. This was the first in a series of surveys to map the entire offshore component of the fault. The fault system has generated numerous powerful earthquakes in the magnitude 7 and 8 range. This mapping will help understand the fault's slip rate, earthquake recurrence intervals, and paleoseismic history. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with multibeam processing software. Geographic information systems (GIS) ready multibeam bathymetry and acoustic backscatter grids are available in the associated data release (https://doi.org/10.5066/F7JH3KG6). These data are not intended to be used for navigation.

How was the data set created?

  1. From what previous works were the data drawn?
    verified tides (source 1 of 1)
    National Oceanic and Atmospheric Administration, 2015, Elfin Cove, AK - Station ID: 9452634: National Oceanic and Atmospheric Administration, online.

    Online Links:

    Type_of_Source_Media: online database
    Source_Contribution: Tide station data
  2. How were the data generated, processed, and modified?
    Date: 2024 (process 1 of 1)
    In May 2015 the USGS, PCMSC mapped offshore Cross Sound in southeast Alaska over the northern section of the Queen Charlotte-Fairweather fault. A Reson 7111 multibeam echosounder was pole-mounted to the Alaska Department of Fish and Game R/V Solstice. The survey line files were imported into Caris HIPS and SIPS software (version 9) for bathymetric processing. Water column sound velocity data that were collected throughout the survey were applied to the bathymetry data and verified tides from the Elfin Cove tide station (9452634) were applied in post-processing. The data were cleaned of obvious bad soundings. GSF line files were exported from Caris HIPS and SIPS software. The data release support file section has sound velocity profiles as a single file (2015-629-FA_ALL_SVP.svp) with geographic locations, times, and sound velocities relative to depth in Caris HIPS and SIPS format. The support file section has the survey vessel file in Caris HIPS and SIPS format (ADFG_Solstice.hvf) that includes the vessel lever arm offsets and multibeam calibration corrections. The support file section has a verified tide table used in post-processing that includes data, time, and verified tide in Caris HIPS and SIPS format. The GSF files should have all this information applied but the files are included in the data release for completion. Data sources used in this process:
    • verified tides
  3. What similar or related data should the user be aware of?
    Dartnell, Peter, Brothers, Daniel S., and Haeussler, Peter J., 2022, Multibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA.

    Online Links:

    Other_Citation_Details:
    Dartnell, P., Brothers, D.S., and Haeussler, P.J., 2022, Multibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA: U.S. Geological Survey data release, https://doi.org/10.5066/F7JH3KG6.

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?
    The Coda Octopus F180 position and motion compensation system has a horizontal positional accuracy of about 0.4 m with Differential Global Positioning Systems (DGPS) corrections and roll and pitch accuracies of about 0.025 degrees (https://www.oceanscan.net/gallery/Data_Sheets/CODA_F180_PRECISION_ALTITUDE__POSITIONING_SYSTEMS.pdf). Accuracies of final products may be lower due to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.
  3. How accurate are the heights or depths?
    The Coda Octopus F180 position and motion compensation system has heave accuracy between 3.5cm - 5cm (https://www.oceanscan.net/gallery/Data_Sheets/CODA_F180_PRECISION_ALTITUDE__POSITIONING_SYSTEMS.pdf). Accuracies of final products may be lower due to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.
  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?
    No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints No access constraints
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 and the Alaska Department of Fish and Game as the originators of the dataset and in products derived from these data. This information is not intended for navigation purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - CMGDS
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in Generic Sensor Format (.gsf) along with CSDGM FGDC-compliant metadata.
  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: Downloadable zip files contains survey day directories which contain the survey line files collected during that day. in format GSF (version Caris HIPS and SIPS (version 9)) Size: 2154
      Network links: https://doi.org/10.5066/P1ED3GXB
    • Cost to order the data: None.

  5. What hardware or software do I need in order to use the data set?
    The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing GSF files. The support files can be viewed with any text reader.

Who wrote the metadata?

Dates:
Last modified: 12-Apr-2025
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_P1ED3GXB/CrossSound_USGS_2015_GSF_multibeam_line_files_metadata.faq.html>
Generated by mp version 2.9.51 on Fri Apr 25 14:57:28 2025