GeoTIFF image of acoustic backscatter collected by the U.S. Geological Survey off of Port Lambton, Ontario within the St. Clair River, 2008 (GeoTIFF, PORTL_05M.TIF)

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
GeoTIFF image of acoustic backscatter collected by the U.S. Geological Survey off of Port Lambton, Ontario within the St. Clair River, 2008 (GeoTIFF, PORTL_05M.TIF)
Abstract:
In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.
  1. How might this data set be cited?
    U.S. Geological Survey, 2010, GeoTIFF image of acoustic backscatter collected by the U.S. Geological Survey off of Port Lambton, Ontario within the St. Clair River, 2008 (GeoTIFF, PORTL_05M.TIF): Open-File Report 2010-1035, 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.

    Denny, Jane F., Foster, David S., Worley, Charles R., and Irwin, Barry J., 2010, Geophysical data collected from the St. Clair River between Michigan and Ontario, Canada, 2008-016-FA: Open-File Report 2010-1035, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -82.516696
    East_Bounding_Coordinate: -82.504297
    North_Bounding_Coordinate: 42.662191
    South_Bounding_Coordinate: 42.653924
  3. What does it look like?
    https://pubs.usgs.gov/of/2010/1035/gis_catalog/mosaic/portl_05m_bs_sm.jpg (JPEG)
    Thumbnail image of acoustic backscatter
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 02-Jun-2008
    Currentness_Reference:
    ground condition
  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 1801 x 2001 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: 17
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -81.000000
      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 0.500000
      Ordinates (y-coordinates) are specified to the nearest 0.500000
      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:
    The data range (digital number) within the backscatter mosaic is 0 to 234. No data are represented by 255.
    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 Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?

This acoustic backscatter mosaic will be used to identify bedforms and surficial sediment distribution within the Upper St. Clair River off of Port Lambton, Ontario. The mosaic will be correlated to sediment samples of the river floor and bottom video and photographs in order to interpret the acoustic facies.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata (source 1 of 1)
    U.S. Geological Survey, unknown, Information unavailable from original metadata.

    Type_of_Source_Media: disc
    Source_Contribution:
    Swath-bathymetric and acoustic-backscatter data were acquired with a SEA, Ltd., SWATHplus interferometric sonar operating at a 234-kHz frequency (http://www.sea.co.uk/swathplus.aspx?nav=products). The SWATHplus transducer was mounted at the bow of the USGS R/V Rafael. Bathymetric data were acquired over variable swath widths ranging from 10 to 100 m, in water depths of about 1 to 25 m. A total of 109 km of swath bathymetric data were collected.
    SWATHplus acquisition software (version 3.05.90) was used to digitally log the bathymetric data at a rate of 30 pings/second and 3,072 samples per swath (ping) in the SWATHplus SXR format. Data collection parameters are saved into a SWATHplus session file in SEA's SXS format. These files can be later used for data replay.
    An Octopus F180R Attitude and Positioning system (see: <http://www.codaoctopus.com/motion/f180/index.asp>) recorded ship motion (heave, pitch, roll, and yaw). These data were transmitted via network connection to the SWATHplus data collection software. The Octopus F180R Inertial Measurement Unit (IMU) was mounted directly above the SWATHplus 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, 3 meters above the F180R IMU, 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.
    Eight sound-velocity profiles were acquired during survey operations at roughly 4-hr intervals using an Applied Microsystems SV Plus V2 Velocimeter (Applied Microsystems, 2008).
  2. How were the data generated, processed, and modified?
    Date: 2009 (process 1 of 7)
    Raw SWATHplus (*sxr) files were unraveled using the University of New Brunswicks Ocean Mapping Group (OMG) SwathEd multibeam processing software (http://www.omg.unb.ca/~jhc/swathed/index.html)/ . The unravel process converts the raw *sxr file to OMG file formats for soundings and backscatter and stores navigation in binary and ASCII files. During the unravel backscatter is also converted to USGS Xsonar/Showimage file format (*. (backscatter) and *.nav files). The Xsonar/Showimage files are desampled to 1024 bytes/ping at 100-m swath, yielding resolution of 0.1m/pixel.
    SwathEd (no version) Person who carried out this activity:
    Jane Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700x2311 (voice)
    5084572310 (FAX)
    jdenny@usgs.gov
    Date: 2009 (process 2 of 7)
    Xsonar/Showimage was used to process the backscatter. Slant range was corrected and data were normalized across swath using a beam pattern routine with the following parameters: 200 pings with a 50-ping overlap, generating *sb (slant-range and beam pattern) files. Navigation was not merged within the Xsonar/Showimage, as navigation data were merged during the unravel routine using SwathEd. Navigation data were plotted and viewed graphically within Xsonar/Showimage for quality assessment.
    Xsonar/Showimage (no version) Person who carried out this activity:
    Jane Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700x2311 (voice)
    5084572310 (FAX)
    jdenny@usgs.gov
    Date: 2009 (process 3 of 7)
    An OMB SwathEd utility backToSwathed was used to convert the processed Xsonar/Showimage files (*.sb) back to OMG format (*.slr). The *.slr files were used to generate a backscatter mosaic using the following routines, with bounds defined during the make_blank routine:
    -Create Blank Map Sheet at 0.5 meter resolution, UTM meters, Zone 17N, WGS84 (make_blank -prime 255 -8bit mosaic) -Copy mosaic.blank to mosaic.mos mosaic.ran -Mosaic the individual sonar lines (mos2 -maxdist 10 -custom_weight MOS_weights mosaic *.slr) -Remove the 1024 byte header from the mosaic.mos file (dd if=mosaic.mos of=mosaic.raw bs=1024 skip =1) -Convert the raw mosaic file to TIFF using Adobe Photoshop (CS3 10.0.1) -A world file was generated for the TIFF image using the UNIX command vi -GeoTIFF Examine, v. 1.01 (www.mentorsoftwareinc.com) was used to convert the TIFF image to a GeoTIFF.
    Adobe Photoshop CS3 was used to apply a linear stretch to the backscatter mosaic. The data range (digital numbers) is 0 to 234; no data are represented by 255. Person who carried out this activity:
    Jane Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700x2311 (voice)
    5084572310 (FAX)
    jdenny@usgs.gov
    Date: 19-Oct-2017 (process 4 of 7)
    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 link to the data in the Distribution_Information section had to be fixed. Fixed link to browse graphic. Attempted to modify http to https where appropriate. Reordered the links in the identification section to have a landing page link as the first link. The source information was incomplete and had to be modified to meet the standard. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. 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 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?
    Foster, David S., and Denny, Jane F., 2009, Quaternary Geologic Framework of the St. Clair River between Michigan and Ontario, Canada: Open-File Report 2009-1137, U.S. Geological Survey, Reston, VA.

    Online Links:

    Beaudoin, Jonathan, 2002, Hitchhiker's Guide to Swathed...: University of New Brunswick Ocean Mapping Group, Fredericton, New Brunswick.

    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?
    Differential Global Positioning System (DGPS) navigation data were acquired with the forward, or primary, Octopus F180R Attitude and Positioning system DGPS antenna and transmitted via a network connection to the SWATHplus data collection software. The F180R Attitude and Positioning system uses 2 L1 antennas for position and heading and an Inertial Measurement Unit (IMU) for motion sensing. The F180R IMU is mounted on the rigid sidemount used to deploy the SWATHplus bathymetric system, and is located directly above the SWATHplus transducers. The F180R antennas are mounted on a rigid horizontal pole, 3 meters above the F180R IMU, offset in a forward/aft configuration (see 'source contribution' for a full description of the F180R). DGPS accuracy is 1 to 3 meters, depending on the distance from a US Coast Guard coastal repeater station (http://www.navcen.uscg.gov/).
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Lines 92-99 were used to generate the final GeoTIFF mosaic, portl_05m.tif. Gaps present in this data are generally in shallow-water areas where the system was not tracking bottom, or poor quality sonar returns precluded use in the completed mosaic.
  5. How consistent are the relationships among the observations, including topology?
    All acoustic backscatter data were collected during USGS cruise 08016 using a SWATHplus 234-kHz swath bathymetric system and an Octopus F180R Attitude and Positioning System. Quality control was conducted during processing of the data. Any spurious data or artifacts were removed or minimized.

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 Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (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?
    • Availability in digital form:
      Data format: This WinZip (version 9.0) file contains a TIFF image and associated world file of backscatter mosaic collected within the St. Clair River between Michigan and Ontario, Canada, 2008 in format GeoTIFF Size: 1
      Network links: https://pubs.usgs.gov/of/2010/1035/gis_catalog/mosaic/portl_05m.zip
    • Cost to order the data: none

  5. What hardware or software do I need in order to use the data set?
    This Zip file contains a GeoTIFF image and 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.

Who wrote the metadata?

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

508-548-8700 x2311 (voice)
508-457-2310 (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/ofr2010-1035/portlbackscatter_05m.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:20:26 2021