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H11044_UTM18_WGS84.TIF: Composite sidescan sonar mosaic of NOAA survey H11044 in West-Central Long Island Sound off Milford, Connecticut (UTM Zone 18, WGS84)

Metadata also available as: OUTLINE | TEXT

Frequently-anticipated questions:

What does this data set describe?

Title:
H11044_UTM18_WGS84.TIF: Composite sidescan sonar mosaic of NOAA survey H11044 in West-Central Long Island Sound off Milford, Connecticut (UTM Zone 18, WGS84)
Abstract:
The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted sidescan sonar mosaics (complete-coverage acoustic images of the sea floor) within specific areas of special interest. The mosaic presented herein covers an area of the sea floor in north-central Long Island Sound off Milford, Connecticut. The mosaics and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The sidescan sonar mosaics also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.
  1. How should this data set be cited?

    U.S. Geological Survey, and U.S. Geological Survey, 200509, H11044_UTM18_WGS84.TIF: Composite sidescan sonar mosaic of NOAA survey H11044 in West-Central Long Island Sound off Milford, Connecticut (UTM Zone 18, WGS84): Open-File Report 2005-1018, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: Data are released via DVD media.
    This is part of the following larger work.

    McMullen, K.Y., Poppe, L.J., Paskevich, V.F., Doran, E.F., Moser, M.S., Christman, E.B., and Beaver, A.L., 2005, Surficial Geologic Interpretation and Sidescan Sonar Imagery of the Sea Floor in West-Central Long Island Sound: Open-File Report 2005-1018, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This digital publication may also be available via the web at pubs.usgs.gov

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -72.869907
    East_Bounding_Coordinate: -72.775833
    North_Bounding_Coordinate: 41.237200
    South_Bounding_Coordinate: 41.151200

  3. What does it look like?

    <http://pubs.usgs.gov/of/2005/1018/data/sidescan/noaa/h11044_utm18_wgs84-thumb.gif> (GIF)
    Thumbnail overview image of the digital sidescan sonar mosaic in UTM produced for NOAA survey H11044
    <http://pubs.usgs.gov/of/2005/1018/data/sidescan/noaa/h11044_utm18_wgs84.gif> (GIF)
    Thumbnail overview image of the digital sidescan sonar mosaic in UTM produced for NOAA survey H11044

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 2001
    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 35739 x 40832 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: 0.9996
      Longitude_of_Central_Meridian: -75
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 0.700010
      Ordinates (y-coordinates) are specified to the nearest 0.700009
      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?

    Band_1

    ObjectID

    Value

    Red

    Green

    Blue

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Larry Poppe
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2314 (voice)
    (508) 457-2310 (FAX)
    lpoppe@usgs.gov

Why was the data set created?

This GIS overlay is a component of the H11044 Survey, Long Island Sound, ArcView GIS database and contains the completed sidescan sonar mosaic for the study area. The image is projected in UTM and has not been enhanced. Light tones represent relatively harder returns, higher backscatter, and generally coarser sediments. Dark tones represent relatively softer returns, lower backscatter, and generally finer grained sediments.

How was the data set created?

  1. From what previous works were the data drawn?

    h11044_utm18_wgs84.tif (source 1 of 1)
    National Oceanic and Atmospheric Administration, h11043_utm18_wgs84.

    Type_of_Source_Media: CD-ROM
    Source_Contribution:
    Original sidescan sonar mosaic created by National Oceanic and Atmospheric Administration (NOAA). This image is projected in UTM to maintain the aspect ratio.

  2. How were the data generated, processed, and modified?

    Date: 2002 (process 1 of 1)
    The sidescan sonar imagery contained in this report was produced from data collected during 2001 as part of NOAA survey H11044 aboard the NOAA Ship RUDE. The data for these surveys were acquired in XTF (extended Triton data format) using an Edgetech (EG&G) 272T sidescan sonar tow fish set to sweep about 100 m to either side of the ship's track. The Edgetech model 272T tow fish emits two 50°-wide beams tilted down 20° from horizontal, and transmits at 100 kHz. Analog side scan sonar data were converted to digital using an EG&G Analog Converter Interface (ACI). These digital data were then recorded through a Triton Elics International ISIS data acquisition system. The sidescan sonar data were multiplexed and filtered to convert the data into the desired processing format and to remove speckle noise and corrected for slant-range distortions, and imported into SonarWeb, an application that creates mosaics from raw XTF sidescan sonar data. The mosaic include the following standards: 1 meter resolution, image 'shine through', and auto contrast adjustment (with a 12.9% contrast increase). The final image was projected in Universal Transverse Mercator to maintain the aspect ratio.

    Person who carried out this activity:

    Marc Moser
    National Oceanic and Atmospheric Administration
    Field Support Liaison
    Hydrographic Systems and Technology Program
    Norfolk, VA 23510
    USA

    (757) 441-6726 (voice)
    Marc.S.Moser@noaa.gov

    Data sources used in this process:
    • XTF sidescan sonar data

    Data sources produced in this process:

    • h11044_utm18_wgs84.tif
    • h11044_utm18_wgs84.tfw

  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?

    There are no attributes associated with a GEOTIFF image.

  2. How accurate are the geographic locations?

    Navigation was by differential GPS; positional accuracy to less than 10 m.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    All collected data were processed and used to generate the digital mosaic.

  5. How consistent are the relationships among the observations, including topology?

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 are freely redistributable with proper metadata and source attribution. Please recognize the National Oceanic and Atmospheric Administration (NOAA) as the originator of this dataset.

  1. Who distributes the data set? (Distributor 1 of 1)

    Larry Poppe
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2314 (voice)
    (508) 457-2310 (FAX)
    lpoppe@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?

    Although this data set has been used by the U.S. Geological Survey (USGS), Connecticut Department of Environmental Protection (CT-DEP), and the National Oceanic and Atmospheric Administration (NOAA), no warranty, expressed or implied, is made by the USGS or NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS, CT-DEP, or NOAA 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. What hardware or software do I need in order to use the data set?

    This image is available as a GEOTIFF image with an accompanying world file. To utilize this 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: 23-Aug-2005
Metadata author:
Lawrence J. Poppe
U.S. Geological Survey
Geologist
U.S. Geological Survey
Woods Hole, MA 02543-1598
USA

(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.8.6 on Wed Aug 24 12:32:17 2005