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- Identification_Information:
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- Citation:
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- Citation_Information:
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- Originator: U.S. Geological Survey
- Publication_Date: 2002
- Title:
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Sea Floor Topography and Backscatter Intensity of the Historic Area Remediation Site
- Geospatial_Data_Presentation_Form: remote-sensing image and raster digital data
- Publication_Information:
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- Publication_Place: Woods Hole, MA
- Publisher: U.S. Geological Survey
- Online_Linkage: <URL: https://pubs.usgs.gov/openfile/of00-503>
- Larger_Work_Citation:
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- Citation_Information:
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- Originator: Butman, Bradford
- Originator: Danforth, William W.
- Originator: Knowles, S.C.
- Originator: May, Brian
- Originator: Serrett, Laurie
- Publication_Date: 2002
- Title:
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Sea Floor Topography and Backscatter Intensity of the Historic Area Remediation Site (HARS), Offshore of New York, Based on Multibeam Surveys Conducted in 1996, 1998, and 2000
- Geospatial_Data_Presentation_Form:
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map, raster digital data, remote-sensing image, tabular digital data, vector digital data
- Series_Information:
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- Series_Name: Open File Reports (OFR)
- Issue_Identification: 00-503
- Publication_Information:
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- Publication_Place: Reston, VA
- Publisher: U.S. Geological Survey
- Online_Linkage: <URL: https://pubs.usgs.gov/openfile/of00-503>
- Description:
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- Abstract:
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This data set includes topography and backscatter intensity of the sea floor of the Historic Area Remediation Site (HARS), located offshore of New York and New Jersey. The data were collected with a multibeam sea floor mapping system on surveys conducted November 23 - December 3, 1996, October 26 - November 11, 1998, and April 6 - 30, 2000. The surveys were conducted using a Simrad EM 1000 multibeam echo sounder mounted aboard the Canadian Hydrographic Service vessel Frederick G. Creed. This multibeam system utilizes 60 electronically aimed receive beams spaced at intervals of 2.5 degrees that insonify a strip of sea floor up to 7.5 times the water depth (swath width of 100 to 200 m within the survey area). The horizontal resolution of the beam on the sea floor is approximately 10% of the water depth (3-5 meters in the survey region). Vertical resolution is approximately 1 percent of the water depth, or 0.3 m. Maps derived from the mulitbeam observations show sea floor topography, shaded relief, and backscatter intensity (a measure of sea floor texture and roughness) at a spatial resolution of 3 m/pixel.
- Purpose:
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The purpose of this project is to map the surficial geology of the sea floor of Historic Area Remediation Site (HARS) and changes in surficial characteristics over time. The sea floor of the HARS, approximately 9 square nautical miles in area, is being remediated by placing at least a one-meter of clean dredged material on top of the existing surface sediments that exhibit varying degrees degradation resulting from previous disposal of dredged and other material. This GIS project presents multibeam and other data in a digital format for analysis and display by scientists, policy makers, managers and the general public. Comparison of the topography and backscatter intensity from the three surveys show changes in topography and surficial sediment properties resulting from placement of dredged material in 1996 and 1997 prior to designation of the HARS, as well as placement of material for remediation of the HARS. This study is carried out cooperatively by the U.S. Geological Survey and the U.S. Army Corps of Engineers.
- Time_Period_of_Content:
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- Time_Period_Information:
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- Range_of_Dates/Times:
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- Beginning_Date: 1996
- Ending_Date: 2000
- Currentness_Reference: ground condition
- Status:
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- Progress: Complete
- Maintenance_and_Update_Frequency: None planned
- Spatial_Domain:
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- Bounding_Coordinates:
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- West_Bounding_Coordinate: -73.900124
- East_Bounding_Coordinate: -73.812264
- North_Bounding_Coordinate: 40.433605
- South_Bounding_Coordinate: 40.349975
- Keywords:
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- Theme:
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- Theme_Keyword_Thesaurus: None
- Theme_Keyword: Geographic Information Systems
- Theme_Keyword: GIS
- Theme_Keyword: Woods Hole Field Center
- Theme_Keyword: WHFC
- Theme_Keyword: United States Geological Survey
- Theme_Keyword: USGS
- Theme_Keyword: Simrad Subsea EM1000
- Theme_Keyword: Frederick G. CREED
- Theme_Keyword: Sea Floor Mapping
- Theme_Keyword: Multibeam Echo Sounder
- Theme_Keyword: Multibeam
- Theme_Keyword: Topographic data
- Theme_Keyword: Sea floor topography
- Theme_Keyword: Bathymetry
- Theme_Keyword: Backscatter intensity
- Theme_Keyword: Sea floor geology
- Theme_Keyword: Surficial geology
- Theme_Keyword: Dredged material
- Theme_Keyword: Dredged material management
- Theme_Keyword: Ocean disposal
- Theme_Keyword: Remediation
- Theme_Keyword: Contaminated sediments
- Place:
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- Place_Keyword_Thesaurus: none
- Place_Keyword: New York
- Place_Keyword: New York Harbor
- Place_Keyword: NY
- Place_Keyword: New Jersey
- Place_Keyword: NJ
- Place_Keyword: Mud Disposal Site
- Place_Keyword: MDS
- Place_Keyword: Historic Area Remediation Site
- Place_Keyword: HARS
- Place_Keyword: Primary Remediation Area
- Place_Keyword: New York Bight
- Place_Keyword: Mid-Atlantic Bight
- Place_Keyword: Exclusive Economic Zone
- Place_Keyword: EEZ
- Place_Keyword: Atlantic Ocean
- Place_Keyword: Ocean
- Place_Keyword: HARS Buffer Zone
- Place_Keyword: Historic Area Remediation Site Buffer Zone
- Access_Constraints:
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These data were 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 have been used by
the USGS, no warranty, expressed or implied, is made by
the USGS 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 in the use of these data or related materials.
- Use_Constraints:
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These data were prepared by an agency of the United
States Government. Neither the United States Government
nor any agency thereof, nor any of 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 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 have been used by
the USGS, no warranty, expressed or implied, is made by
the USGS 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 in the use of these data or related materials.
- Point_of_Contact:
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- Contact_Information:
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- Contact_Organization_Primary:
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- Contact_Organization: U. S. Geological Survey
- Contact_Person: Bradford Butman
- Contact_Position: Oceanographer
- Contact_Address:
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- Address_Type: mailing and physical address
- Address: 384 Woods Hole Rd
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Country: USA
- Contact_Voice_Telephone: 508.548.8700x2212
- Contact_Facsimile_Telephone: 508-457-2309
- Contact_Electronic_Mail_Address: bbutman@usgs.gov
- Hours_of_Service: 8 a.m. - 5 p.m.
- Data_Set_Structure:
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- Data_Set_Part:
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- Part_Type: raster digital data
- Part_Name: Gridded bathymetry
- Part_Description:
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Bathymetric data was compiled from multibeam echosounder surveys conducted during the time periods of; 11/23/96 to 12/3/96, 10/26/98 to 11/11/98 and 4/6/2000 to 4/30/2000.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars1996_3m
- Part_Description:
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Bathymetric soundings from 1996 multibeam echosounder survey gridded at 3 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars1998_3m
- Part_Description:
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Bathymetric soundings from 1998 multibeam echosounder survey gridded at 3 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars2000_3m
- Part_Description:
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Bathymetric soundings from 2000 multibeam echosounder survey gridded at 3 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars1996_12m
- Part_Description:
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Bathymetric soundings from 1996 multibeam echosounder survey gridded at 12 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars1998_12m
- Part_Description:
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Bathymetric soundings from 1998 multibeam echosounder survey gridded at 12 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: hars2000_12m
- Part_Description:
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Bathymetric soundings from 2000 multibeam echosounder survey gridded at 12 meters.
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: 12hars1996_12m
- Part_Description:
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Smoothed bathymetric soundings at 12 m resolution from 1996 multibeam survey. Smoothing of the bathymetric data was accomplished using a 12-cell by 12-cell (144 m by 144 m) median filter with the focalmedian routine (ARC/INFO geographic information system software, Environmental Systems Research Institute, Inc., version 7.2.1).
- Data_Set_Part:
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- Part_Type: Arcview/Arcinfo grid
- Part_Name: 12hars1998_12m
- Part_Description:
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Smoothed bathymetric soundings at 12 m resolution from 1998 multibeam survey. Smoothing of the bathymetric data was accomplished using a 12-cell by 12-cell (144 m by 144 m) median filter with the focalmedian routine (ARC/INFO geographic information system software, Environmental Systems Research Institute, Inc., version 7.2.1).
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: 12hars2000_12m
- Part_Description:
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Smoothed bathymetric soundings at 12 m resolution from 2000 multibeam survey. Smoothing of the bathymetric data was accomplished using a 12-cell by 12-cell (144 m by 144 m) median filter with the focalmedian routine (ARC/INFO geographic information system software, Environmental Systems Research Institute, Inc., version 7.2.1).
- Data_Set_Part:
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- Part_Type: vector digital data
- Part_Name: Bathymetric contours
- Part_Description:
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Bathymetric contours at 1 and 5 meter intervals based on smoothed multibeam observations. Bathymetric data were contoured using ARC/INFO geographic information system software (Environmental Systems Research Institute, Inc., version 7.2.1). Smoothing of the bathymetric data was accomplished using a 12-cell by 12-cell (144 m by 144 m) median filter with the focalmedian routine. Topographic contours at a 1-meter interval were generated from the grid using the latticecontour routine.
- Data_Set_Part:
-
- Part_Type: Arcview shapefile
- Part_Name: 12hars9612c1g.shp
- Part_Description:
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Bathymetric contours at 1 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 1996 multibeam echosounder survey.
- Data_Set_Part:
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- Part_Type: Arcview shapefile
- Part_Name: 12hars9812c1g.shp
- Part_Description:
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Bathymetric contours at 1 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 1998 multibeam echosounder survey.
- Data_Set_Part:
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- Part_Type: Arcview shapefile
- Part_Name: 12hars0012c1g.shp
- Part_Description:
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Bathymetric contours at 1 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 2000 multibeam echosounder survey.
- Data_Set_Part:
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- Part_Type: Arcview shapefile
- Part_Name: 12hars9612c5g.shp
- Part_Description:
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Bathymetric contours at 5 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 1996 multibeam echosounder survey.
- Data_Set_Part:
-
- Part_Type: Arcview shapefile
- Part_Name: 12hars9812c5g.shp
- Part_Description:
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Bathymetric contours at 5 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 1998 multibeam echosounder survey.
- Data_Set_Part:
-
- Part_Type: Arcview shapefile
- Part_Name: 12hars0012c5g.shp
- Part_Description:
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Bathymetric contours at 5 meter intervals, from bathymetry grids compiled from bathymetric soundings collected on the 2000 multibeam echosounder survey.
- Data_Set_Part:
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- Part_Type: remote-sensing images
- Part_Name: Sun illuminated topography
- Part_Description:
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The shaded relief image (3 m pixel size) was created by vertically exaggerating the topography four times and then artificially illuminating the relief by a light source positioned 45 degrees above the horizon from the north. In the resulting image, topographic features are enhanced by strong illumination on the northward-facing slopes and by shadows cast on southern slopes. The image also accentuates small features (relief of a few meters) that could not be effectively shown as contours alone at this scale. Unnatural-looking features or patterns oriented parallel or perpendicular to survey tracklines (tracklines run north-south) are artifacts of data collection and environmental conditions.
- Data_Set_Part:
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- Part_Type: remote-sensing image
- Part_Name: Hars1996Sun.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing sea floor topography with an artificial illumination source. It was compiled from multibeam echosounder data collected in 1996. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
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- Part_Type: remote-sensing image
- Part_Name: Hars1998Sun.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing sea floor topography with an artificial illumination source. It was compiled from multibeam echosounder data collected in 1998. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
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- Part_Type: remote-sensing image
- Part_Name: Hars2000Sun.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing sea floor topography with an artificial illumination source. It was compiled from multibeam echosounder data collected in 2000. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
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- Part_Type: remote-sensing images and raster digital data
- Part_Name: Backscatter Intensity
- Part_Description:
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Backscatter intensity, the intensity of the acoustic return from the sea floor from the multibeam system, is a function of the properties of the surficial sediments and of the bottom roughness. Generally, a strong return (light gray tones) is associated with rock or coarse-grained sediment, and a weak return (dark gray tones) with fine-grained sediments. However, the micro-topography, such as ripples, burrows, and benthic populations also affect the reflectivity of the sea floor. Direct observations, using bottom photography or video, and surface samples, are needed to verify interpretations of the backscatter intensity data. The backscatter data have a weak striping that runs parallel to the ship´s track. Some of the striping is the result of poor data return at nadir that appears as evenly-spaced thin speckled lines. Some striping is also due to critical angle effects, where the intensity of return varies as a function of the angle of incidence of the incoming sound on the seafloor (Hughes-Clark and others, 1997).
- Data_Set_Part:
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- Part_Type: remote-sensing image
- Part_Name: Hars1996Mos.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing backscatter intensity. It was compiled from multibeam echosounder data collected in 1996. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: remote-sensing image
- Part_Name: Hars1998Mos.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing backscatter intensity. It was compiled from multibeam echosounder data collected in 1998. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: remote-sensing image
- Part_Name: Hars2000Mos.tif
- Part_Description:
-
This is a 3 meter resolution tiff image representing backscatter intensity. It was compiled from multibeam echosounder data collected in 2000. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: ArcView/Arcinfo grid
- Part_Name: hars96bsgrd
- Part_Description:
-
This is a 3 meter resolution grid representing backscatter intensity. It was compiled from multibeam echosounder data collected in 1996.
- Data_Set_Part:
-
- Part_Type: ArcView/Arcinfo grid
- Part_Name: hars98bsgrd
- Part_Description:
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This is a 3 meter resolution grid representing backscatter intensity. It was compiled from multibeam echosounder data collected in 1998.
- Data_Set_Part:
-
- Part_Type: ArcView/Arcinfo grid
- Part_Name: hars00bsgrd
- Part_Description:
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This is a 3 meter resolution grid representing backscatter intensity. It was compiled from multibeam echosounder data collected in 2000.
- Data_Set_Part:
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- Part_Type: remote-sensing image
- Part_Name: Pseudocolored Backscatter Intensity
- Part_Description:
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The backscatter intensity is combined with the topography to display the distribution of intensity in relation to the topography. In the image shown here, the backscatter intensity is represented by a suite of eight colors ranging from blue, which represents low intensity, to red, which represents high intensity. These data are draped over a shaded relief image created by vertically exaggerating the topography four times and then artificially illuminating the relief by a light source positioned 45 degrees above the horizon from an azimuth of 350 degrees. The resulting image displays light and dark intensities within each color band that result from a feature's position with respect to the light source. For example, north-facing slopes, receiving strong illumination, show as a light intensity within a color band, whereas south-facing slopes, being in shadow, show as a dark intensity within a color band.
- Data_Set_Part:
-
- Part_Type: remote-sensing image
- Part_Name: Hars1996Pseudo.tif
- Part_Description:
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This is a 3 meter resolution tiff image representing backscatter intensity with a RGB color scale. It was compiled from multibeam echosounder data collected in 1996. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: remote-sensing image
- Part_Name: Hars1998Pseudo.tif
- Part_Description:
-
This is a 3 meter resolution tiff image representing backscatter intensity with a RGB color scale. It was compiled from multibeam echosounder data collected in 1998. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: remote-sensing image
- Part_Name: Hars1996Pseudo.tif
- Part_Description:
-
This is a 3 meter resolution tiff image representing backscatter intensity with a RGB color scale. It was compiled from multibeam echosounder data collected in 2000. There is a corresponding tiff world file for georeferencing purposes.
- Data_Set_Part:
-
- Part_Type: raster digital data
- Part_Name: Backscatter intensity difference grids
- Part_Description:
-
The difference grids were created in Arcview 3.2 utilizing the Spatial Analyst 1.0 extension. Backscatter intensity grids from two different years were opened and the younger grid was subtracted from the older grid.
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bs96_00ntc
- Part_Description:
-
The change in backscatter intensity between the 1996 and 2000 survey computed by subtracting the backscatter intensity in 2000 from the intensity in 1996 (negative values indicate increased backscatter in 2000 compared to 1996).
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bs96_98ntc
- Part_Description:
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The change in backscatter intensity between the 1996 and 1998 survey computed by subtracting the backscatter intensity in 1998 from the intensity in 1996 (negative values indicate increased backscatter in 1998 compared to 1996).
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bs98_00ntc
- Part_Description:
-
The change in backscatter intensity between the 1998 and 2000 survey computed by subtracting the backscatter intensity in 2000 from the intensity in 1998 (negative values indicate increased backscatter in 2000 compared to 1998).
- Data_Set_Part:
-
- Part_Type: raster digital data
- Part_Name: Bathymetry difference grids
- Part_Description:
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bathy96_00ntc
- Part_Description:
-
The difference in topography between 1996 and 2000 computed by subtracting the water depths as measured in 2000 from the depths measured in 1996 (positive values indicate shallower water in 2000 compared to 1996).
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bathy96_98ntc
- Part_Description:
-
The difference in topography between 1996 and 1998 computed by subtracting the water depths as measured in 1998 from the depths measured in 1996 (positive values indicate shallower water in 1998 compared to 1996).
- Data_Set_Part:
-
- Part_Type: Arcview/Arcinfo grid
- Part_Name: bathy98_00ntc
- Part_Description:
-
The difference in topography between 1998 and 2000 computed by subtracting the water depths as measured in 2000 from the depths measured in 1998 (positive values indicate shallower water in 2000 compared to 1998).
- Data_Quality_Information:
-
- Attribute_Accuracy:
-
- Attribute_Accuracy_Report: No attributes are associated with these data.
- Logical_Consistency_Report: These data are logically consistent.
- Completeness_Report:
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These data are complete. No further processing and/or
modifications will be made to these data.
- Positional_Accuracy:
-
- Horizontal_Positional_Accuracy:
-
- Horizontal_Positional_Accuracy_Report:
-
These data were navigated with a Differential Global
Positioning System (DGPS); they are accurate to +/- 3
meters, horizontally.
- Vertical_Positional_Accuracy:
-
- Vertical_Positional_Accuracy_Report:
-
These data have been corrected for vessel motion
(roll, pitch, heave, yaw) and tidal offsets, and referenced to
mean lower low water. The theoretical vertical resolution
of the Simrad EM-1000 multibeam echosounder is 1 % of
water depth; roughly 30 - 50 cm within the study area.
However, the working vertical resolution of the system, is
roughly +/- 50 cm.
- Lineage:
-
- Process_Step:
-
- Process_Description:
-
(1) Data and acquisition processing at sea
After the echo sounder data
were logged onto the hard disk of the Sun workstation, a
suite of processing software developed by the Ocean
Mapping Group (www.omg.unb.ca/~jhc/SwathEd.html)
was used to correct for artifacts and errors that may have
been introduced during data collection. This software also
enhanced the corrected data by resolving beam pattern
and aspect ratio distortions and by imposing a linear
contrast stretch before it generated bathymetric and
sidescan sonar image mosaicks in a Mercator projection.
All data processing described here is initiated using Silicon
Graphics workstations as soon as each acquisition file is
closed by the Simrad Mermaid workstation (usually at the
end of each survey line). Additional
processing was done in the lab to correct for fluctuations in sea level during the survey and for artifacts in the
data files that were not corrected in the field (see below).
The processing and editing steps on board the ship were:
(A.) Demultiplex, or unravel, the acquired Simrad
data files using RT to generate separate files containing
navigation, depth soundings, sidescan sonar backscatter
values, and sound velocity information.
(B.) Automatically reject bad data
(autoRejectSoundings). For the multibeam soundings,
reject data outside expected depth ranges (operator's
decision based on nautical chart data); for navigation data,
reject fixes with poor GPS statistics.
(C.) Edit the navigation data on-screen using jview to
remove undesirable points, including turns at the ends of
survey lines.
(D.) Edit the multibeam soundings on-screen using
swathed to remove individual anomalous soundings.
(E). Merge tidal information and the corrected
navigation back (mergetide and mergenav) into the data
files. Tidal information was obtained from the NOAA
tide
server using tide station 8531680 located at Sandy Hook,
//www.co-ops.nos.noaa.gov/) Final tidal corrections were made in the lab using a different procedure (see below).
(F.) Map the bathymetric soundings from each
processed data file onto a Mercator grid using weigh_grid
with node spacings and scale selected by the operator.
(G.) Map the extracted sidescan sonar backscatter
values onto a digital mosaic using mos2 in the Mercator
projection at a scale selected by the user.
(H.) Using addSUN, generate bathymetric raster files
using the mapped grid node information to depict the depth
information in a shaded relief Mercator map. A Mercator
projection allows individual map areas to be joined edge to
edge when creating a composite image. The shaded relief
images were generated using a sun elevation angle of 45
degrees from an azimuth of 0 degrees, and a vertical
exaggeration of four times to emphasize seafloor features.
(I.) Generate a false colored image using mix_ci by
combining the bathymetric and backscatter raster mosaics
into a single image, also in the Mercator projection.
(2) Data processing and analysis
Processing in the lab included:
(A.) Removing sound refraction artifacts from the data (using the
refraction tool in swathed) due to insufficient sound velocity
profile information and varying water masses within the
study area.
(B.)The measured elevations were adjusted for fluctuations in sea level during the survey by subtracting tidal elevations predicted by a tidal model and low-frequency sea level observed at the National Oceanic and Atmospheric Administration Sandy Hook tide station located at 40 degrees 28 minutes N., 74 degrees 0.6 minutes W. The tidal model utilized 9 constituents derived from a 4-month bottom pressure record obtained at Station A, located at 40 degrees 23.4 minutes N., 73 degrees 47.1 minutes W. in 38 m water depth about 2.7 km east of the HARS, during the winter of 1999-2000. An estimate of the error due to sea level remaining in the multibeam observations after the sea level correction is about 3 cm.
(C.)The difference grids were created in Arcview 3.2 utilizing the Spatial Analyst 1.0 extension. Backscatter intensity/Bathymetry grids from two different years were opened and the younger grid was subtracted from the older grid.
All mapped files are in the Mercator projection, having a
central longitude of -75 degrees West, a latitude of true scale of 40 degrees north
and the horizontal datum is WGS84. The vertical datum is mean lower low water.
- Process_Date: 1996 to 2000
- Process_Contact:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- Contact_Person: William Danforth
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Operational Geologist
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 384 Woods Hole Road
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Country: USA
- Contact_Voice_Telephone: 508.548.8700x2274
- Contact_Facsimile_Telephone: 508.457.2310
- Contact_Electronic_Mail_Address: bdanforth@usgs.gov
- Hours_of_Service: 8 a.m. to 5 p.m. EST
- Spatial_Data_Organization_Information:
-
- Direct_Spatial_Reference_Method: Raster
- Raster_Object_Information:
-
- Raster_Object_Type: Pixel
- Row_Count: 2487
- Column_Count: 3098
- Spatial_Reference_Information:
-
- Horizontal_Coordinate_System_Definition:
-
- Planar:
-
- Grid_Coordinate_System:
-
- Grid_Coordinate_System_Name: other grid system
- Other_Grid_System's_Definition:
-
Mercator
Standard Parallel: 40.0
Longitude of Central Meridian: -75
False Easting: 0
False Northing: 0
- Planar_Coordinate_Information:
-
- Planar_Coordinate_Encoding_Method: row and column
- Coordinate_Representation:
-
- Abscissa_Resolution: 3
- Ordinate_Resolution: 3
- Planar_Distance_Units: meters
- Geodetic_Model:
-
- Ellipsoid_Name: World Geodetic System 84
- Semi-major_Axis: 6378137
- Denominator_of_Flattening_Ratio: 298.257
- Vertical_Coordinate_System_Definition:
-
- Depth_System_Definition:
-
- Depth_Datum_Name: Mean lower low water
- Depth_Resolution: 0.3
- Depth_Distance_Units: Meters
- Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
- Distribution_Information:
-
- Distributor:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- Contact_Person: Bradford Butman
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Oceanographer
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 384 Woods Hole Road
- City: Woods Hole
- State_or_Province: Massachusetts
- Postal_Code: 02543-1598
- Country: USA
- Contact_Voice_Telephone: 508.548.8700x2212
- Contact_Facsimile_Telephone: 508.457.2309
- Contact_Electronic_Mail_Address: bbutman@usgs.gov
- Hours_of_Service: 8 a.m. to 5 p.m. EST
- Distribution_Liability:
-
These data were 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 have been used by the USGS, no warranty, expressed or implied, is made by the USGS 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 in the use of these data or related materials.
- Distribution_Information:
-
- Distributor:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: U.S. Geological Survey Information Services
- Contact_Address:
-
- Address_Type: mailing address
- Address: Box 25286 Denver Federal Center
- City: Denver
- State_or_Province: Colorado
- Postal_Code: 80225-0046
- Country: USA
- Contact_Voice_Telephone: 303.202.4700
- Contact_Facsimile_Telephone: 303.202.4188
- Hours_of_Service: 8 a.m. to 5 p.m. Mountain Time
- Distribution_Liability:
-
These data were 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 have been used by the USGS, no warranty, expressed or implied, is made by the USGS 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 in the use of these data or related materials.
- Metadata_Reference_Information:
-
- Metadata_Date: 20010618
- Metadata_Contact:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- Contact_Person: Brad Butman
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Oceanographer
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 384 Woods Hole Road
- City: Woods Hole
- State_or_Province: MA
- Postal_Code: 02543-1598
- Contact_Voice_Telephone: 508.548.8700x2212
- Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
- Metadata_Standard_Version: FGDC-STD-001-1998
- Metadata_Time_Convention: Universal time
Generated by mp (URL: http://geology.usgs.gov/tools/metadata/tools/doc/mp.html) version 2.7.3 on Wed Nov 28 17:12:41 2001