Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2003 Title: 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: Publication_Place: Woods Hole, MA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2003/of01-470 Larger_Work_Citation: Citation_Information: Originator: Butman, Bradford Originator: Gutierrez, Benjamin T. Originator: ten Brink, Marilyn Buchholtz Originator: Schwab, William C. Originator: Blackwood, Dann S. Originator: Mecray, Ellen L. Originator: Middleton, Tammie J. Publication_Date: 2003 Title: Photographs of the Sea Floor Offshore of New York and New Jersey Geospatial_Data_Presentation_Form: map, raster digital data, remote-sensing image, tabular digital data, vector digital data Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: of01-470 Publication_Information: Publication_Place: Woods Hole, MA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2003/of01-470/ Description: Abstract: 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. These data have been reprocessed from those presented in Butman and others (2002) (see cross reference) to correct for an error in the software that projected the data on a sphere rather than on the WGS84 ellipsoid, and to stretch the backscatter intensity and shaded relief images to match the Hudson Shelf Valley images. The horizontal error in placement of the data published by Butman and others (2002) was 0 in the northwestern corner of the HARS, and reached about 12 m in the southeastern corner. Further work is needed to match the backscatter intensity for the 1996, 1998, and 2000 surveys. Purpose: These data are included in this publication to provide bathymetry and backscatter intensity of the sea floor for maps showing the locations of images and samples obtained in the New York Bight. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1996 Ending_Date: 2000 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -73.900124 East_Bounding_Coordinate: -73.812264 North_Bounding_Coordinate: 40.433605 South_Bounding_Coordinate: 40.349975 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Sea floor photographs Theme_Keyword: Bottom photography Theme_Keyword: Sea floor video Theme_Keyword: Sediment texture Theme_Keyword: Sediment grain size Theme_Keyword: Seabed Observation and sampling system Theme_Keyword: SEABOSS Theme_Keyword: R/V Oceanus Theme_Keyword: R/V Endeavor Theme_Keyword: R/V Seaward Explorer Theme_Keyword: F/V Alpha and Omega Theme_Keyword: Woods Hole Field Center Theme_Keyword: WHFC Theme_Keyword: United States Geological Survey Theme_Keyword: USGS Theme_Keyword: Geographic Information Systems Theme_Keyword: GIS Theme_Keyword: Simrad Subsea EM1000 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: Ocean disposal Theme_Keyword: Contaminated sediments Place: 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: Hudson Shelf Valley Place_Keyword: Hudson Canyon Place_Keyword: New York Bight Place_Keyword: New York Bight Apex Place_Keyword: Mid-Atlantic Bight Place_Keyword: Exclusive Economic Zone Place_Keyword: EEZ Place_Keyword: Atlantic Ocean Place_Keyword: Ocean Access_Constraints: None Use_Constraints: This information is not for navigational purposes. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U. S. Geological Survey Contact_Person: Bradford Butman Contact_Position: Oceanographer Contact_Address: 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_Credit: The multibeam observations in the HARS were originally published in Butman and others (2002), U.S. Geological Survey Open-File Report 00-503 (see cross-reference citation). These data have been reprocessed to correct for an error in the software that projected the data on a sphere rather than on the WGS84 ellipsoid, and to stretch the backscatter intensity and shaded relief images the same as the Hudson Shelf Valley images. Cross_Reference: Citation_Information: Originator: Butman, Bradford Originator: Danforth, William W. Originator: Knowles, Stephen C. Originator: May, Brian Originator: Serrett, Laurie Publication_Date: 2002 Title: 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: map, raster digital data, remote-sensing image, tabular digital data, vector digital data Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: of00-503 Publication_Information: Publication_Place: Woods Hole, MA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2000/of00-503 Data_Set_Structure: Data_Set_Part: Part_Type: remote-sensing images Part_Name: Sun illuminated topography Part_Description: 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: Part_Type: remote-sensing image Part_Name: Hars1996Sun.tif Part_Description: 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: Part_Type: remote-sensing image Part_Name: Hars1998Sun.tif Part_Description: 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: Part_Type: remote-sensing image Part_Name: Hars2000Sun.tif Part_Description: 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: Part_Type: remote-sensing images and raster digital data Part_Name: Backscatter Intensity Part_Description: 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 sea floor (Hughes-Clark and others, 1997). Data_Set_Part: Part_Type: remote-sensing image Part_Name: Hars1996Mos.tif Part_Description: 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: 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: remote-sensing image Part_Name: Pseudocolored Backscatter Intensity Part_Description: 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: 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_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No attributes are associated with these data. Logical_Consistency_Report: These data are logically consistent. Completeness_Report: 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 sea floor 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 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.) Two corrections have been made to the HARS multibeam data as published in Butman and others (2002). (1) The backscatter intensity data between 180-220 was stretched to 0-255 (The data published in 2002 between 180-225 was stretched to 0-255). The shaded relief data between 150-200 was stretched to 0-255 (as in the 2002 data). Aging of the multibeam transducer and software changes implemented to correct the near-nadir response make the backscatter intensity observed in 1996, 1998, and 2000 not directly comparable. Further work is needed to match the backscatter intensities between the 1996, 1998 and 2000 surveys. (2) The data were also reprocessed to correct for an error in the UNB software that projected the data on a sphere rather than on the WGS84 ellipsoid. The horizontal error in placement of the data published by Butman and others (2002) was 0 in the northwestern corner of the HARS, and reached about 12 m in the southeastern corner. 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 2003 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: 20021216 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: 508-457-2212 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: Universal time