bcksctter.tif: Backscatter intensity and sun-illuminated topographic imagery of the seafloor in the Stellwagen Bank National Marine Sanctuary region.

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Page C. Valentine
Originator: Jessica L. Baker
Originator: Tanya S. Unger
Publication_Date: 2005
Title:
bcksctter.tif: Backscatter intensity and sun-illuminated topographic imagery of the seafloor in the Stellwagen Bank National Marine Sanctuary region.
Edition: 1.0
Geospatial_Data_Presentation_Form: remote-sensing image
Series_Information:
Series_Name: Scientific Investigations Map
Issue_Identification: 2840
Publication_Information:
Publication_Place: Woods Hole Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage:
<http://pubs.usgs.gov/sim/2005/2840/data/backscatter/bcksctter.zip>
Larger_Work_Citation:
Citation_Information:
Originator: Page C. Valentine, editor
Publication_Date: 2005
Title:
Sea floor image maps showing topography, sun-illuminated topography, backscatter intensity, ruggedness, slope, and the distribution of boulder ridges and bedrock outcrops in the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts
Edition: 1.0
Series_Information:
Series_Name: Scientific Investigations Map
Issue_Identification: 2840
Publication_Information:
Publication_Place: Woods Hole Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Other_Citation_Details: 1:60,000, 6 maps, 12 sheets
Online_Linkage: <http://pubs.usgs.gov/sim/2005/2840/>
Description:
Abstract:
This data set contains the sun-illuminated topographic imagery and backscatter intensity generated from a multibeam sonar survey of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts, an area of approximately 1100 square nautical miles. The Stellwagen Bank NMS Mapping Project is designed to provide detailed maps of the Stellwagen Bank region's environments and habitats and the first complete multibeam topographic and sea floor characterization maps of a significant region of the shallow EEZ.

Data were collected on four cruises over a two year period from the fall of 1994 to the fall of 1996. The surveys were conducted aboard the Canadian Hydrographic Service vessel Frederick G. Creed, a SWATH (Small Waterplane Twin Hull) ship that surveys at speeds of up to 16 knots. The multibeam data were collected utilizing a Simrad Subsea EM 1000 Multibeam Echo Sounder (95 kHz) that is permanently installed in the hull of the Creed.

Purpose:
Development of interpretive seabed maps, sea floor imagery, and a GIS database that are accessible to scientists, policymakers, managers, and the general public.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1994
Ending_Date: 1998
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -70.600
East_Bounding_Coordinate: -70.0333
North_Bounding_Coordinate: 42.800
South_Bounding_Coordinate: 42.0833
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: Geographic Information Systems
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: Woods Hole Science Center
Theme_Keyword: WHSC
Theme_Keyword: SIMRAD SUBSEA EM 1000
Theme_Keyword: Frederick G. Creed
Theme_Keyword: Multibeam Echo Sounder
Theme_Keyword: Sea floor topography
Theme_Keyword: bathymetry
Theme_Keyword: shaded relief imagery
Theme_Keyword: backscatter intensity
Theme_Keyword: psuedo color encoded
Theme_Keyword: GeoTIFF image
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: oceans and estuaries
Theme_Keyword: geoscientificInformation
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: elevation
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Massachusetts
Place_Keyword: MA
Place_Keyword: Stellwagen Bank National Marine Sanctuary
Place_Keyword: SBNMS
Place_Keyword: Shallow EEZ
Place_Keyword: EEZ
Place_Keyword: Gulf of Maine
Place_Keyword: Atlantic Ocean
Place_Keyword: North Atlantic
Place_Keyword: Boston
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 (USGS) as the source of this information.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Page C. Valentine
Contact_Organization: U.S. Geological Survey
Contact_Position: Research Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2239
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: pvalentine@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
<http://pubs.usgs.gov/sim/2005/2840/data/backscatter/bcksctter-thumb.gif>
Browse_Graphic_File_Description:
Thumbnail image showing backscatter intensity and sun-illuminated topography of the seafloor in Stellwagen Bank National Marine Sanctuary region.
Browse_Graphic_File_Type: GIF
Browse_Graphic:
Browse_Graphic_File_Name:
<http://pubs.usgs.gov/sim/2005/2840/data/backscatter/bcksctter-browse.gif>
Browse_Graphic_File_Description:
Browse image showing backscatter intensity and sun-illuminated topography of the seafloor in Stellwagen Bank National Marine Sanctuary region.
Browse_Graphic_File_Type: GIF
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.0.0.535
Cross_Reference:
Citation_Information:
Originator: Page C. Valentine
Originator: Tammie J. Middleton
Originator: Sarah J. Fuller
Publication_Date: 2001
Title:
Sea floor maps showing topography, sun-illuminated topography, and backscatter intensity of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts
Edition: 1.01
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 00-410
Publication_Information:
Publication_Place: Woods Hole Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/of/of00-410/>
Cross_Reference:
Citation_Information:
Originator: Page C. Valentine
Originator: Jessica L. Baker
Originator: Tanya S. Unger
Publication_Date: 2003
Title:
Backscatter intensity and sun-illuminated sea Floor topography of the Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts
Edition: 1.0
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: Geologic Investigations Map
Issue_Identification: I-2676-C
Publication_Information:
Publication_Place: Woods Hole Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The ship's position was determined with an accuracy of 10 m or better using a Magnavox 4200 geographic positioning system (GPS) receiver in conjunction with differential GPS corrections transmitted by U.S. Coast Guard radio beacons. At the start of each day, casts were made to record the sound velocity profile of the water column in the area to be surveyed. This information is used by the data acquisition system to correct for the refraction of the transmitted multibeam sound signal as it travels through the water to and from the sea floor.
Logical_Consistency_Report:
Multibeam echo sounder data was collected aboard the Canadian Hydrographic Service vessel Frederick G. Creed, an aluminum SWATH (Small Waterplane Area Twin Hull) ship that surveys at speeds up to 16 knots. The ship has two submerged torpedo-shaped hulls that support the main deck via two thin struts. This design reduces wave motion on the ship and resistance to the ship's forward motion through the water, thus making it a very stable platform at high survey speeds. Stability of the ship is also enhanced by the computer-controlled action of four stabilizer fins located fore and aft on the inboard side of the hulls. The stabilizers control the pitch and roll of the vessel and allow adjustment of the heel and trim of the ship while under way.

An Applied Analytics POS/MV motion sensor located in the hull near the EM 1000 transducer detects changes in pitch, roll, and heave of the vessel. The motion information is recorded concurrently with the acquired multibeam signal and both are logged in a single file on the Sun workstation and made available to other workstations for further processing.

Completeness_Report:
The sidescan-sonar backscatter data are displayed in real time on the Sun workstation using software designed and written by the Ocean Mapping Group, University of New Brunswick. This display allows data gaps to be identified during the survey and also gives a measure of the data quality.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Sounding rates depend on water depth but vary from 2 to 4 per second in water depths less than 100 meters. Horizontal spatial resolution at these sounding rates is on the order of 10% of the water depth at 16 knots; however, vertical resolution is approximately 1% or better in the same depth range.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Sounding rates depend on water depth but vary from 2 to 4 per second in water depths less than 100 meters. Horizontal spatial resolution at these sounding rates is on the order of 10% of the water depth at 16 knots; however, vertical resolution is approximately 1% or better in the same depth range.
Lineage:
Process_Step:
Process_Description:
Multibeam data were processed using SwathEd, a suite of multibeam software editing and display tools developed by Dr. John Hughes Clarke of the Ocean Mapping Group, University of New Brunswick (UNB).

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 6199
Column_Count: 3631
Vertical_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Mercator
Mercator:
Standard_Parallel: 41.650000
Longitude_of_Central_Meridian: -70.316667
False_Easting: 0
False_Northing: 0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 13.000000
Ordinate_Resolution: 13.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Backscatter imagery combines the sun-illuminated topography with the backscatter intensity (shown here in color) of the sea floor. Backscatter intensity is a measure of the hardness and roughness of the sea floor as determined from the strength of sound waves reflected from the seabed during the survey. High-backscatter materials (red and orange) are coarse sand, gravel (including piles and ridges of boulders), and rock outcrops. Moderate backscatter (green) represents sand or muddy sand. Low backscatter (blue) represents sandy mud and mud. These interpretations apply best in region's of low regional topography, because steep slopes can divert the paths of some of the reflected sound waves away from the survey vessel. Thus, seabed that slopes steeply away from the survey track can produce a lower backscatter intensity than if it were level. Unnatural-looking stripes and patterns oriented parallel or perpendicular to survey track lines are artifacts of data collection. Blank areas represent places where no data exists.

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Page C. Valentine
Contact_Organization: U.S. Geological Survey
Contact_Position: Research Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2239
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: pvalentine@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: TIFF
Format_Specification: GeoTIFF
Format_Information_Content:
A zip archive containing the GeoTIFF image, associated world file, and metadata.
File_Decompression_Technique: zip
Transfer_Size: 0.000
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://pubs.usgs.gov/sim/2005/2840/data/backscatter/bcksctter.zip>
Offline_Option:
Offline_Media: DVD-ROM
Recording_Capacity:
Recording_Density: 4.75
Recording_Density_Units: Gbytes
Recording_Format: UDF
Fees: None
Technical_Prerequisites:
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.

Metadata_Reference_Information:
Metadata_Date: 20050822
Metadata_Review_Date: 20050822
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Page C. Valentine
Contact_Position: Research Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2239
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: pvalentine@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Access_Constraints: None
Metadata_Use_Constraints: None
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.6 on Mon Aug 22 08:35:25 2005