5-meter per pixel acoustic backscatter mosaic collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (FI_SONAR_5M, UTM Zone 18N, WGS 84, GeoTIFF)

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Frequently anticipated questions:


What does this data set describe?

Title:
5-meter per pixel acoustic backscatter mosaic collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (FI_SONAR_5M, UTM Zone 18N, WGS 84, GeoTIFF)
Abstract:
The U.S. Geological Survey (USGS) mapped approximately 336 square kilometers of the lower shoreface and inner-continental shelf offshore of Fire Island, New York in 2011 using interferometric sonar and high-resolution chirp seismic-reflection systems. This report presents maps of bathymetry, acoustic backscatter, the coastal plain unconformity, the Holocene marine transgressive surface and modern sediment thickness. These spatial data support research on the Quaternary evolution of the Fire Island coastal system and provide baseline information for research on coastal processes along southern Long Island. More information about this field activity and the data collected can be found at the Field Activity Web Page (http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-005-FA)
  1. How might this data set be cited?
    U.S. Geological Survey, 2014, 5-meter per pixel acoustic backscatter mosaic collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (FI_SONAR_5M, UTM Zone 18N, WGS 84, GeoTIFF): Open-File Report 2014-1203, 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.

    Schwab, William C., Denny, Jane F., and Baldwin, Wayne E., 2014, Maps Showing Bathymetry and Modern Sediment Thickness on the Inner- Continental Shelf Offshore of Fire Island, New York: pre-Hurricane Sandy: Open-File Report 2014-1203, U.S. Geological Survey, Coastal and Marine Geology Program, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -73.280265
    East_Bounding_Coordinate: -72.738660
    North_Bounding_Coordinate: 40.759320
    South_Bounding_Coordinate: 40.535635
  3. What does it look like?
    http://pubs.usgs.gov/of/2014/1203/data/GIS/sonar/fi_sonar5m_sm.jpg (JPEG)
    Gray-scale image of interferometric sonar mosaic collected offshore of Fire Island, NY
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 20-May-2011
    Ending_Date: 08-Jun-2011
    Currentness_Reference:
    ground condition during 20110520 - 20110523, 20110525 - 20110601; 20110604 - 20110608.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: remote-sensing image
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 4764 x 9056 x 1, type Pixel
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -75.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 5.000000
      Ordinates (y-coordinates) are specified to the nearest 5.000000
      Planar coordinates are specified in meters
      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?
    Entity_and_Attribute_Overview:
    There are no attributes associated with a GeoTIFF image. Image pixel values contain acoustic reflectivity values normalized to a 24-bit data range. Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values). The background color is set to 0-0-0 and can be turned off without removing data values.
    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?
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?

This GeoTIFF represents approximately 2800 line kilometers of acoustic backscatter data collected in 2011. These data were collected using an interferometric sonar (Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M (234 kHz)) by the U.S. Geological Survey during USGS survey 2011-005-FA. Acoustic backscatter data were used to define the surficial sediment distribution on the inner-continental shelf offshore of Fire Island, New York to help assess environmental change caused by natural processes and human activities.

How was the data set created?

  1. From what previous works were the data drawn?
    none (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Raw Interferometric Data.

    Type_of_Source_Media: online
    Source_Contribution:
    Survey: Survey lines were run at an average speed of 5 knots. Lines 1 through 27 were run at a 75-m line spacing to achieve full coverage of the seafloor in a priority area of interest in the nearshore, in water depths less than 15 meters. Lines 28 through 109 were run at a 150-m line spacing, with the exception of tie lines (lines 52 through 60, 65 through 67, 89 through 92), which were run at approximately a 2-km line spacing. Sonar: Swath-bathymetric and acoustic-backscatter data were acquired with a SEA, Ltd., SWATHplus-M interferometric sonar operating at a frequency of 234 kHz and a variable range (increased or decreased manually depending on water depth). The system was operated with a transmit power: 80 percent, 4096 samples per channel, and a variable range (increased or decreased depending on water depth). The SWATHplus-M was mounted on the port side of the M/V Scarlett Isabella during survey operations. A Coda Octopus F180R Attitude and Positioning system recorded ship motion (heave, pitch, roll, and yaw). These data were transmitted via network connection to the SWATHplus-M acquisition software. The Octopus F180R Inertial Measurement Unit (IMU) was mounted directly above the SEA SWATHplus-M transducers, to minimize lever arm offsets that can lead to positioning errors. The F180R uses two L1 antennas for position and heading accuracy. The antennas are mounted on a rigid horizontal pole, positioned at the top of the sidemount, with a horizontal separation of 1 meter and are offset from the IMU in a forward/aft configuration. The forward offset of the primary antenna from the IMU is 0.5 meters, with no port/starboard offset. Sound Velocity Profiles: 135 sound velocity profiles were acquired during survey operations at roughly 1 to 3 hour intervals using an Odim MVP30 motion vessel profiler. The MVP30 failed during survey operations. Sound velocity profiles were only collected during JD140 through 149 (lines 1 through 47). While much effort was devoted to cleaning the data and minimizing survey artifacts, some artifacts may still be seen in the final GeoTIFF including an along track artifact at nadir (the ship track). These artifacts are especially noticeable in the shallow nearshore region of the survey. More information about this field activity and the data collected can be found at the Field Activity Web Page (http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-005-FA)
  2. How were the data generated, processed, and modified?
    Date: 2014 (process 1 of 7)
    Raw (SXR) : Raw SXR bathymetry and acoustic backscatter data were acquired with the SEA SWATHplus acquisition software (version 3.07). The SWATHplus acquisition software applies the pitch, roll, heave, yaw and heading data supplied by the Coda Octopus F180R IMU, to compensate for any ship motion. Jane F. Denny performed this and all subsequent process steps. Person who carried out this activity:
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2311 (FAX)
    jdenny@usgs.gov
    Date: 2014 (process 2 of 7)
    Import SXR to Chesapeake Technologies SonarWiz: SWATHplus raw acoustic backscatter (sonar) files (SXR) were imported into Chesapeake Technology Inc.'s SonarWiz software (version 5.06.0029). The sonar data were processed to correct for towfish altitude (i.e. proper bottom tracking of the sea floor), and slant-range and beam pattern distortions inherent in the sonar data. Beam pattern distortions were minimized using an empirical gain normalization function. A composite mosaic was generated within SonarWiz, and exported as a 24-bit GeoTIFF image file, with no data values explicitly set to 0, 0, 0.
    Date: 2014 (process 3 of 7)
    Import to ArcGIS 9.3.1: The 24-bit GeoTIFF was added to an ArcGIS 9.3.1 map project. For best display, the image symbology was set to stretched, display background value 0, minimum-maximum stretch of 40 (low) to 120 (high).
    Date: 04-Mar-2016 (process 4 of 7)
    Edits to the metadata were made to fix any errors that MP v 2.9.32 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). All of the online links to the publication pages and data had to be fixed. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 5 of 7)
    USGS Thesaurus keywords added to the keyword section. 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
    Date: 18-Nov-2019 (process 6 of 7)
    Crossref DOI link was added as the first link in the metadata. 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
    Date: 08-Sep-2020 (process 7 of 7)
    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?
    Schwab, William C., Baldwin, Wayne E., Hapke, Cheryl J., Lentz, Erika E., Gayes, Paul T., Denny, Jane F., List, Jeffrey H., and Warner, John C., 2013, Geologic Evidence for Onshore Sediment Transport from the Inner Continental Shelf: Fire Island, New York: Journal of Coastal Research Volume 29, Issue 3, pp. 526-544., Coastal Education and Research Foundation, Inc., Florida, USA.

    Online Links:

    Foster, David S., Swift, Ann B., and Schwab, William C., 1999, Stratigraphic Framework Maps of the nearshore area of southern Long Island from Fire Island to Montauk Point, NY: Open-File Report 99-559, U.S. Geological Survey, Reston, VA.

    Online Links:

    Schwab, William C., Thieler, E. Robert, Denny, Jane F., Danforth, William W., and Hill, Jenna C., 2000, Seafloor sediment distribution off southern Long Island, New York: Open-File Report 00-243, U.S. Geological Survey, Reston, VA.

    Online Links:


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

  1. How well have the observations been checked?
    There are no attributes associated with a GeoTIFF image. Image pixel values contain acoustic reflectivity values normalized to a 24-bit data range. Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values). The background color is set to 0-0-0 and can be turned off without removing data values.
  2. How accurate are the geographic locations?
    Navigation was acquired with Differential Global Positioning System and Wide Area Augmentation System (DGPS+WAAS), which is accurate to + or - 1 to 2 meters, horizontally. The forward, or primary, Coda Octopus F180R Attitude and Positioning system antenna was used to acquire DGPS data and transmit via a network connection to the SEA SWATHplus data acquisition software. The F180R Attitude and Positioning system uses 2 L1 antennas for position and heading and an Inertial Measurement Unit (IMU) for motion sensing (heave, pitch, roll and yaw). The F180R IMU is mounted directly above the SEA SWATHplus-M transducers on the sidemount. The F180R antennas are mounted at the top of the sidemount offset in a forward/aft configuration. The offsets were applied within the SWATHplus and Coda Octopus F180R acquisition software.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Line 1 - 51, 61 - 64, 68 - 87, and 93 - 109 were used to generate the GeoTIFF image. Lines 52-60, 65 - 67, and 89 - 92 are tie lines collected orthogonal to the shoreline. Lines l27f5, l28f1, l28f2, l29f4, and l61f1 were not included in the mosaic, as the raw data files were not recorded. Tie lines were not incorporated in the GeoTIFF image.
  5. How consistent are the relationships among the observations, including topology?
    This image represents interferometric acoustic backscatter data collected offshore of Fire Island, New York. Gaps generally occur along-track and between adjacent lines where complete coverage of the sea floor was not possible due to narrow swath widths. This primarily occurs in the shallowest regions of the survey.

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 redistributable 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)
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2311 (FAX)
    jdenny@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  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. Is there some other way to get the data?
    none
  6. What hardware or software do I need in order to use the data set?
    This zip file contains a GeoTIFF image with an accompanying world file. To utilize these data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image. A free spatial data viewer, ArcGIS Explorer, capable of displaying the data is available from Esri at www.esri.com. The zip file also contains associated metadata.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Jane F. Denny
U.S. Geological Survey
Geologist
394 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x 2311 (voice)
508-457-2311 (FAX)
jdenny@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/open_file_report/ofr2014-1203/fi_sonar_5m.faq.html>
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