Geospatial Navigational Data Associated with Chirp Sub-Bottom Profiles Collected During USGS Field Activity Number 2023-325-FA in June and August 2023 from the Chandeleur Islands, Louisiana

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Frequently anticipated questions:

What does this data set describe?

Title:
Geospatial Navigational Data Associated with Chirp Sub-Bottom Profiles Collected During USGS Field Activity Number 2023-325-FA in June and August 2023 from the Chandeleur Islands, Louisiana
Abstract:
As part of the 2022 Disaster Supplemental project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted a nearshore geophysical survey to map the shoreface and inner shelf, as well as characterize stratigraphy near the Chandeleur Islands, Louisiana (LA) in June and August 2023. The purpose of this study was to conduct a morphologic and geologic assessment of the impacts of the 2020 and 2021 hurricane seasons within part of the Breton National Wildlife Refuge (specifically around Hewes Point and Monkey Bayou). These geophysical data will be used to quantify sediment redistribution resulting from storms. The data release associated with this metadata record serves as an archive of high-resolution chirp sub-bottom trace data and navigation files. Shapefiles (.shp) provided in the data release represent point and polyline vector datasets of Field Activity Number (FAN) 2023-325-FA chirp sub-bottom profile trackline, start of line, and 1,000-shot-interval locations.
Supplemental_Information:
Additional survey and data details are available from the Field Activity Collection System (FACS) logs, which are included in the download file, 2023-325-FA_logs.zip.
  1. How might this data set be cited?
    Forde, Arnell S., 20240515, Geospatial Navigational Data Associated with Chirp Sub-Bottom Profiles Collected During USGS Field Activity Number 2023-325-FA in June and August 2023 from the Chandeleur Islands, Louisiana:.

    This is part of the following larger work.

    Forde, Arnell S., Miselis, Jennifer L., Stalk, Chelsea A., and Buster, Noreen A., 20240515, Chirp Sub-Bottom Profile Geophysical Data Collected in 2023 From the Chandeleur Islands, Louisiana: U.S. Geological Survey data release doi:10.5066/P1HOLGKM, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.89780
    East_Bounding_Coordinate: -88.83650
    North_Bounding_Coordinate: 30.07260
    South_Bounding_Coordinate: 29.73750
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 17-Jun-2023
    Ending_Date: 08-Aug-2023
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector digital data (point and polyline)
  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.
    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 0.0197889864. Longitudes are given to the nearest 0.0227019979. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is WGS_1984.
      The ellipsoid used is WGS_84.
      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:
    The shapefiles created as part of this geospatial dataset are a derivative of the ASCII CSV navigation files provided in 2023-325-FA_nav.zip, which is included in the data release. The navigation and geospatial files share the same attribute labels and definitions, aside from "FID" and "Shape", which are specific to the .shp files. The detailed attribute descriptions for these files are provided in the data dictionary (DataDictionary_SBP.docx), the metadata are not complete without this file. The survey's trackline file, 2023-325-FA_trkln.shp (40 data records), is a polyline geospatial dataset of all the chirp sub-bottom profile tracklines; 2023-325-FA_1000sht.shp (369 data records) is a point geospatial dataset representing the 1,000th shot interval; and 2023-325-FA_sol.shp (40 data records) provides the start of each seismic line as a point geospatial dataset.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information were generated by the individual 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)
    • Arnell S. Forde
  2. Who also contributed to the data set?
    Funding and (or) support for this study were provided by the Department of Interior Supplemental Appropriations for Disaster Recovery Activities Task 1, part of the Extending Government Funding and Delivering Emergency Assistance Act (Public Law 117-43) and the USGS Coastal and Marine Hazards and Resources Program. The authors thank Andrew Farmer of SPCMSC for his assistance in data collection and piloting the Research Vessel (R/V) Sallenger. Field activity planning performed by Noreen Buster and Jennifer Miselis; data collection conducted by Chelsea Stalk and Jennifer Miselis; and data processing performed by Arnell Forde. This document was improved by scientific/editorial and metadata reviews from Nancy DeWitt and Breanna Williams of the SPCMSC.
  3. To whom should users address questions about the data?
    Arnell S. Forde
    U.S. Geological Survey
    Geologist
    600 4th Street South
    Saint Petersburg, FL
    USA

    (727) 502-8000 (voice)
    aforde@usgs.gov

Why was the data set created?

The purpose of the data release described herein is to archive and disseminate digital chirp sub-bottom profile data and associated files collected during USGS FAN 2023-325-FA (subFANs 23BIM05 and 23BIM10). Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/fan_info.php?fan=2023-325-FA.

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: 23-Jan-2024 (process 1 of 2)
    Navigation information was extracted from the seismic trace headers (seismic data available from the data release) using Seismic Unix release 44 software (Cohen and Stockwell, 2010), processed with PROJ.5.1.0 software (https://proj.org/) to generate Universal Transverse Mercator (UTM) Zone 16 North (N) coordinates from latitude and longitude coordinates (World Geodetic System of 1984, WGS84), and then saved as ASCII text files in comma-separated values (CSV) format. Navigation files for each sub-bottom line, saved by line number, were concatenated into comma-delimited text files (.csv) so they could be represented geospatially in geographic information system (GIS) software. The final output files are as follows: (1) 2023-325-FA_nav.csv contains unique shotpoint positions (along each line) for the entire survey, (2) 2023-325-FA_1000sht.csv includes the 1,000-shot-interval locations that were generated to correlate shot locations along the trackline with evenly spaced 1,000-shot index markers along the top of the printable profile images, and (3) 2023-325-FA_sol.csv has the start-of-line locations for each trackline. These CSV files are provided in 2023-325-FA_nav.zip. Person who carried out this activity:
    Arnell S. Forde
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    727-502-8000 (voice)
    aforde@usgs.gov
    Data sources used in this process:
    • *.txt
    Data sources produced in this process:
    • 2023-325-FA_nav.csv
    • 2023-325-FA_1000sht.csv
    • 2023-325-FA_sol.csv
    Date: 23-Jan-2024 (process 2 of 2)
    The reformatted text files referenced in the previous process step were then further processed using Esri ArcMap 10.8.2 software to generate shapefiles. The 1,000-shot navigation file, 2023-325-FA_1000sht.csv, provided in the data release was imported into Esri ArcMap software to produce a geographic representation of the 1,000 shotpoint data collected within the survey area. A 1,000-shot-interval point shapefile (2023-325-FA_1000sht.shp) was generated to correlate shot locations with evenly spaced 1,000-shot index markers along the top of the printable profile images. Likewise, a point shapefile containing the start of line locations for all chirp tracklines, that is based on the reformatted text file 2023-325-FA_sol.csv, was used to create 2023-325-FA_sol.shp. Finally, the 2023-325-FA_nav.csv file containing unique shotpoint positions was imported to ArcGIS to produce a geographic representation of the sub-bottom profile tracklines collected within the survey area. The 'PointsToLine' script (located in the ArcToolbox) was used to create a shapefile (2023-325-FA_trkln.shp) in which individual chirp shotpoints were connected to form tracklines. A non-proprietary version of the shapefiles was created by utilizing the ArcToolbox "Map to KML" tool, which converted each layer to keyhole markup language (KML) format prior to them being compressed (zipped) and saved as a .kmz file (2023-325-FA.kmz). All geospatial files can be found in 2023-325-FA_gis.zip. Person who carried out this activity:
    Arnell S. Forde
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    aforde@usgs.gov
    Data sources used in this process:
    • 2023-325-FA_1000sht.csv
    • 2023-325-FA_sol.csv
    • 2023-325-FA_nav.csv
    Data sources produced in this process:
    • 2023-325-FA_shots.shp
    • 2023-325-FA_sol.shp
    • 2023-325-FA_trkln.shp
    • 2023-325-FA.kmz
  3. What similar or related data should the user be aware of?
    Cohen, J.K., and Stockwell, J.W., Jr., 2010, Seismic Un*x Release No. 44: An open source software package for seismic research and processing: Center for Wave Phenomena, Colorado School of Mines, Golden, Colorado.

    Online Links:

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?
    As the sub-bottom profile data were acquired, the position of the vessel was continuously determined by an Applanix POS MV Wavemaster II inertial aided navigation system (IANS), which is accurate to within 0.5-2 meters (m). Positions from the POS MV IANS were recorded and written to the seismic trace headers every 0.20 seconds, with unique navigation fixes being recorded every second. The approximately 3-meter offset between the chirp and vessel's IANS reference point has not been accounted for in the comma-delimited American Standard Code for Information Interchange (ASCII) navigation or geospatial files.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    A total of 40 seismic lines were collected during this field activity.
  5. How consistent are the relationships among the observations, including topology?
    These datasets are from one field activity with consistent instrument calibrations. Seismic data were collected during two surveys, which occurred on June 17 (Leg 1; subFAN 23BIM05) and August 5–8, 2023 (Leg 2; subFAN 23BIM10).

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints None. These data are held in the public domain.
Use_Constraints Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research.
  1. Who distributes the data set? (Distributor 1 of 1)
    SPCMSC Data Management Group
    U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    gs-g-spcmsc_data_inquiries@usgs.gov
  2. What's the catalog number I need to order this data set? 2023-325-FA_shots.shp, 2023-325-FA_sol.shp, 2023-325-FA_trkln.shp, 2023-325-FA.kmz, DataDictionary_SBP.docx
  3. What legal disclaimers am I supposed to read?
    This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    The geospatial files were created for use with Esri ArcGIS 10.8.2 software. They may also be viewed with QGIS (https://www.qgis.org/en/site/, 2024), Google Earth (https://earth.google.com/, 2024), or other GIS software capable of importing the data.

Who wrote the metadata?

Dates:
Last modified: 15-May-2024
Metadata author:
SPCMSC Data Management Group
U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
gs-g-spcmsc_data_inquiries@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/2023-325-FA_geospatial_metadata.faq.html>
Generated by mp version 2.9.51 on Thu May 16 10:13:55 2024