Enhanced sidescan-sonar TIFF images in a UTM projection on the inner continental shelf off the northern Oregon and southern Washington

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Frequently anticipated questions:


What does this data set describe?

Title:
Enhanced sidescan-sonar TIFF images in a UTM projection on the inner continental shelf off the northern Oregon and southern Washington
Abstract:
Two 21-day field operations were conducted in 1997 and 1998 in the estuaries and on the inner continental shelf off the northern Oregon and southern Washington coast. These cruises aboard the R/V Corliss were run in order to generate reconnaissance maps of the seafloor geology and the shallow subsurface stratigraphy using sidescan-sonar and seismic-reflection mapping techniques. The 1998 cruise also collected sediment grab samples, bottom photographs, and video images to verify the sidescan-sonar imagery and to document the seafloor geology. The combination of these data with previously collected sediment sample data (Robert, 1974; Nittrouer, 1978; and Smith et. al., 1980) has been used to define the extent and lithology of shelf sediments associated with the Columbia River littoral cell. This work is one component of a larger project studying the erosion of the Washington Oregon coasts and is being coordinated by the U.S. Geological Survey and the Washington State Department of Ecology. The reasons for collecting these data are to provide a regional synthesis of the offshore geology for this project and to support a wide variety of management decisions and to provide a basis for further process-oriented investigations.
Supplemental_Information:
Roberts, R.W., 1974, Marine sedimentological data of the Washington continental shelf: University of Washington, Department of Oceanography Special Report 57, 129p. Nittrouer, C.A., 1978, The process of detrital sediment accumulation in a continental shelf environment: an examination of the Washington shelf: PhD Thesis, University of Washington, Seattle, WA. 243p. Smith, J.M., Messmer, L.W., Phipps, J.B., Samuelson, D.F., and Schermer, E.D., 1980, Grays Harbor and Chehalis River improvements to navigation environmental studies - Grays Harbor ocean disposal study: literature review and preliminary benthic sampling: U.S. Army Corps of Engineers Internal Report.
  1. How might this data set be cited?
    Twichell, David C., 2000, Enhanced sidescan-sonar TIFF images in a UTM projection on the inner continental shelf off the northern Oregon and southern Washington: Open-File Report 00-167, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Twichell, David C., Cross, VeeAnn A., and Parolski, Kenneth F., 2000, Sidescan-sonar Imagery, Surface Sediment Samples, and Surficial Geologic Interpretation of the Southwestern Washington Inner Continental Shelf Based on Data Collected During Corliss Cruises 97007 and 98014: Open-File Report 00-167, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -124.500000
    East_Bounding_Coordinate: -123.800000
    North_Bounding_Coordinate: +47.350000
    South_Bounding_Coordinate: +45.900000
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 27-Aug-1997
    Beginning_Time: 20040000Z
    Ending_Date: 16-Sep-1998
    Ending_Time: 18430000Z
    Currentness_Reference:
    1998
  5. What is the general form of this data set?
  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, 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: 10
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123.000000
      Latitude_of_Projection_Origin: +00.000000
      False_Easting: 500000
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 2
      Ordinates (y-coordinates) are specified to the nearest 2
      Planar coordinates are specified in Meters
      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    Sidescan-sonar imagery
    TIFF image (Source: none)
    Filename
    The image filename is a combination of the area from which it originated (ar1 to ar4), and a segement number. If the imagery is from 1998, a 98 is included in the filename. For example, 'ar1_1.gz' is the TIFF image in area1, segment 1, collected in 1997. The file 'ar1_198.gz' corresponds to the TIFF image in area1, segment 1, collected in 1998. (Source: User defined) character set
    Entity_and_Attribute_Overview:
    This is a collection of digital sidescan sonar imagery in GEOTIF format (the TFW world file is included for those who can't read 'geotif' format). These images have a resolution of 2 m/pixel and have had a stretch applied to the images. These images are compressed with the GZIP utility in order to save disk space. The UTM projection is in Zone 10, using the GRS80 ellipsoid.
    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)
    • David C. Twichell
  2. Who also contributed to the data set?
    Seafloor Mapping Group
  3. To whom should users address questions about the data?
    David C. Twichell
    U.S. Geological Survey
    Oceanographer
    U.S. Geological Survey
    Woods Hole Field Center
    384 Woods Hole Road
    Woods Hole, MA
    USA

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

Why was the data set created?

This is a collection of digital sidescan-sonar imagery in TIFF image format with corresponding TIFF world files for image registration. These images are in a UTM projection with an image resolution is 2 m/pixel.

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: Aug-1998 (process 1 of 5)
    Sidescan-sonar data were collected using an EdgeTech sidescan-sonar system and logged to a Triton QMIPS data acquisition system. The EdgeTech system acquired data at a rate of 7.5 pulses/sec yielding a total swath width of 200m (100m range to each side of the sidescan-sonar towfish). The digital sidescan-sonar data were processed and mapped to provide proper geographic orientation of the data. Although the EdgeTech system is a dual-frequency system (100kHz and 500kHz), this particular study only processed and used the 100kHz data. The processing steps of the sidescan-sonar data included; subsampling the raw sidescan-sonar data using a median filtering routine to suppress speckle noise and reduce file size, and correcting for slant-range distortion, signal attenuation, and dropped sonar lines using the XSonar software package (Danforth et al., 1991). The sidescan-sonar data was then mapped into its proper geographic location at a resolution of 2 m/pixel using techniques summarized by Paskevich (1996).  The study area was broken into 4 areas (area1 being the northenmost, area4 the southernmost) so that each individual area would be a workable file size within the remote sensing software package PCI. Because this particular study consists of reconnaissance lines spaced approximately 5km apart, no mosaicking steps were applied.  Line crossings had no adjustments or shifts applied to the geographic position of the data. Some of the 1997 sidescan-sonar data was collected in an 8-bit format. These files were tone-matched to the 16-bit data. After tone matching, an enhancement was applied to all the sidescan sonar imagery such that the maximum pixel value is 254 with the minimum pixel value of 0. The imagery was then transferred to a background of 255. Rectangular segments of each of the 4 areas from each year of surveying were then exported as TIFF image files with associated world files for georeferencing. Images in a geographic coordinate system were then reprojected to a UTM projection. Due to the large size of the TIF images, they were compressed with the program GZIP such that the filenameconforms to the 8.3 format. An example of a filename is ar1_1.gz. Person who carried out this activity:
    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    U.S. Geological Survery
    Woods Hole Field Center
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Data sources used in this process:
    • Danforth, W.W., O'Brien, T.F., and Schwab, W.C., 1991, USGS image processing system: near real-time mosaicking of high-resolution sidescan-sonar data: Sea Technology, Jan., 1991, p. 54-59.
    • Paskevich, V.F., 1996, MAPIT: An improved method for mapping digital sidescan sonar data using the Woods Hole Image Processing System (WHIPS) software: U.S. Geological Survey Open-File Report 96-281, 73p.
    Date: 31-Mar-2017 (process 2 of 5)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 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.). The original metadata was available in HTML only, so had to be reformatted. The citation in the identification section was completely redone, including adding links to the data and larger work citation. Added ISO 19115 Topic Category keywords. The standard order process section in the distribution was modified to include the link to the data. 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 Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 3 of 5)
    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 4 of 5)
    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 5 of 5)
    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?
    The sidescan-sonar data is merged with navigation collected with P-CODE GPS.  No instrumentation was available to estimate the range to the sidescan-sonar towfish. However, most of the data were acquired in fairly shallow water, therefore the layback (wire out) was minimal.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    All sidescan-sonar data collected on the two cruises, CRLS97007 and CRLS98014, are represented in these files.
  5. How consistent are the relationships among the observations, including topology?
    All of the sidescan-sonar data were collected and processed in the same manner, with the following exception: In 1997, 14 files representing portions or all of 8 lines of data were collected and stored as 8-bit data rather than 16-bit data. These lines are indicated in the 'tracks97' shapefile with the "acquired" attribute.

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:
The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    Nancy Soderberg
    U.S. Geological Survey
    Data Librarian
    U.S. Geological Survey
    Woods Hole Field Center
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 (voice)
    508-457-2313 (FAX)
    nsoderberg@usgs.gov
  2. What's the catalog number I need to order this data set? U.S. Geological Survey CD-ROM Open-File Report
  3. What legal disclaimers am I supposed to read?
    This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.
  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 user must have a program capable of reading and processing 'geotiff' images.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
U.S. Geological Survey
Woods Hole Field Center
384 Woods Hole Rd
Woods Hole, MA
USA

508-548-8700 (voice)
508-457-2310 (FAX)
vatnipp@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/ofr2000-167/uenhtif_meta.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:20:16 2021