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 a 190.3 km square area of the sea floor in the West-Central Basin of Long Island Sound.
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.
U.S. Geological Survey, and National Oceanic and Atmospheric Association, 2005, H11045_GEO1M_WGS84_EN.tif: Enhanced and Inverted Mosaic of Sidescan Sonar Survy H11045 in Geographic: U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
Beaulieu, E., Poppe, L.J., Paskevich, V.F., Doran, E.F., Chauveau, B.E., Crocker, J.M., Beaver, A.L., and Schattgen, P.T., 2005, Sidescan Sonar Imagery and Surficial Geologic Interpretation of the Sea Floor off Bridgeport, Connecticut: Open-File Report 2005-1162, U.S. Geological Survey, Coastal and Marine Geology Program., Woods Hole Science Center, Woods Hole, MA.Online Links:
This is a Raster data set. It contains the following raster data types:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitude and longitude values are specified in Decimal degrees.
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.
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
This GIS overlay, which is a component of the GIS database for NOAA Survey H11045 in the West-Central Basin of Long Island Sound, contains the completed sidescan sonar mosaic for the study area. The image is geographic and has been inverted and enhanced. Light tones represent relatively harder returns, higher backscatter, and generally coarser sediments. Dark tones represent relatively lightly returns, lower backscatter, and generally finer grained sediments.
National Oceanic and Atmospheric Administration, h11045_1m.tif.
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. The mosaic include the following standards: 1 meter resolution, image 'shine through' to account for areas of overlap, and auto contrast adjustment. The final image was projected in Universal Transverse Mercator to maintain the aspect ratio.
Person who carried out this activity:
(757) 441-6726 (voice)
bryan.chauveau@noaa.org
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
There are no attributes associated with a GEOTIFF image
Navigation was by differential GPS; positional accuracy to less than 10m.
All collected data were processed and used to generate the digital mosaic
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 U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration as the originators of this dataset.
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
h11045_geo1m_wgs84_en.tif
Although this data set has been used by the USGS and 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 or NOAA in the use of these data or related materials.
| Data format: | Two files: h11045_geo1m_wgs84_en.tif and h11045_geo1m_wgs84_en.tfw in format TIFF Size: 239.838 |
|---|---|
| Media you can order: |
DVD-ROM
(Density 4.75
Gigabytes)
(format UDF)
Note: The user must have a system with a DVD capable of reading an UDF standard DVD-R disk. |
User must have a program capable of reading and processing "geotiff" images.
(508) 548-8700 x2277 (voice)
(508) 457-2310 (FAX)
ebeaulieu@usgs.gov
