MB_BACKPC10M.TIF - 10-m resolution image of shaded relief multibeam bathymetry in Massachusetts Bay, pseudocolored by backscatter intensity

Metadata also available as - [Outline] - [Parseable text]

Frequently-anticipated questions:

What does this data set describe?

Title:
MB_BACKPC10M.TIF - 10-m resolution image of shaded relief multibeam bathymetry in Massachusetts Bay, pseudocolored by backscatter intensity
Abstract:
The U.S. Geological Survey has conducted geologic mapping to characterize the sea floor offshore of Massachusetts. The mapping was carried out using a Simrad Subsea EM 1000 Multibeam Echo Sounder on the Frederick G. Creed on four cruises conducted between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick. The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) project that presents images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys that will serve the needs of research, management and the public.
  1. How should this data set be cited?

    Butman, Bradford, Valentine, Page C. , and Danforth, William W. , 2007, MB_BACKPC10M.TIF - 10-m resolution image of shaded relief multibeam bathymetry in Massachusetts Bay, pseudocolored by backscatter intensity: Data Series 99, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Butman, Bradford, Valentine, Page C., Middleton, Tammie J., and Danforth, William W., 2007, A GIS Library of Multibeam Data for Massachusetts Bay and the Stellwagen Bank National Marine Sanctuary, Offshore of Boston, Massachusetts: Data Series 99, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -70.788907
    East_Bounding_Coordinate: -70.599983
    North_Bounding_Coordinate: 42.322212
    South_Bounding_Coordinate: 42.203333

  3. What does it look like?

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

    Beginning_Date: 1994
    Ending_Date: 1998
    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 8060 x 7220 x 1, type Pixel

    2. What coordinate system is used to represent geographic features?

      The map projection used is Mercator.

      Projection parameters:
      Standard_Parallel: 41.650000
      Longitude_of_Central_Meridian: -70.316667
      False_Easting: 0.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 10.000000
      Ordinates (y-coordinates) are specified to the nearest 10.000000
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 0.5
      Depth_Distance_Units: Meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    Band_1

    ObjectID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Value

    Red

    Green

    Blue

    Count

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?

    U.S. Geological Survey
    c/o Bradford Butman
    Oceanographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2212 (voice)
    (508) 457-2309 (FAX)
    bbutman@usgs.gov

    Hours_of_Service: 8 a.m. - 5 p.m.

Why was the data set created?

This GeoTIFF (Tagged Image File Format) image shows shaded-relief multibeam bathymetry, pseudo-colored by backscatter intensity, in Massachusetts Bay at 10-m resolution.

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Multibeam bathymetric survey data collected by USGS in Massachusetts Bay, 1994-1998.

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

    Date: Unknown (process 1 of 3)
    A suite of processing software (called SwathEd) (www.omg.unb.ca/~jhc/SwathEd.html), developed by the Ocean Mapping Group at the University of New Brunswick (UNB), Canada, was used to process and grid the multibeam bathymetric soundings and backscatter intensity data, and to produce images. The metadata for the grids describes the processing steps applied to the navigation and bathymetric soundings. The following processing steps produced the shaded relief image of bathymetry, colored by backscatter intensity:
    1. Create backscatter files that can be then mosaicked from the backscatter time series:
    Command line: getBeamPattern filename (prefix only) Command line: makess -pixel 3.0 -beam_patt beampatt filename (prefix only) output.ss Command line: glfill output.ss output.ss_fill (fills in data dropouts).
    2. Mosaic all the backscatter files created in the last step (for each output.ss_fill), and then use a two point linear contrast stretch to enhance the backscatter image.
    Command line: mos2 -autoseam -maxazi 10 -maxdist 10 mosaic_file output.ss_fill Command line: stretchacres -low 180 -high 220 -in mosaic_file -out mosaic_file.stretch
    3. Create a shaded relief image of the bathymetry using SwathEd routine addSUN (sun elevation of 45 degrees from 350, vertically exaggerating 4 times).
    Command line: addSUN -elev 45 -azi350 -vert_exag 4.0 gridFile.r4 filename.shade
    4. Use a two point linear contrast stretch to enhance the shaded relief image:
    Command line: stretchacres -low 150 -high 200 -in filename.shade -out filename_shade.stretch
    5. Create an image of shaded-relief topography, colored by backscatter intensity:
    Command line: mix_ci -c mosaic_file.stretch -i filename_shade.stretch -m mosaic_file.pseudo
    6. Create a tiff from the psuedocolored backscatter mosaic file using the netpbm utilities (<http://netpbm.sourceforge.net/>):
    Command line: rawtopgm -headerskip 1024 image_width image_height mosaic_file.pseudo | pnmtotiff -none - > mosaic_pseudo.tif
    7. Create an ESRI world file (tfw) for the pseudocolored backscatter intensity image for import to ArcView or ArcGIS. Copy bounding box and resolution information from the jview program output to the .tfw file.
    Command line: jview mosaic_file.pseudo

    Person who carried out this activity:

    William Danforth
    U.S. Geological Survey
    Operational Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2274 (voice)
    (508) 457-2310 (FAX)
    bdanforth@usgs.gov

    Hours_of_Service: 8 a.m. to 5 p.m. EST
    Date: Unknown (process 2 of 3)
    Reprocessing to correct projection error
    An error in the UNB processing software that resulted in the multibeam observations not being properly projected onto a plane was discovered in 2003. These software errors were corrected and the data re-gridded. The images of pseudocolored backscatter intensity in the Stellwagen Bank region presented here may differ from preliminary versions included in the following publications:
    Butman, B., and Lindsay, J.A. (Eds.), 1999, A marine GIS Library for Massachusetts Bay: focusing on Disposal sites, Contaminated Sediments, and Sea Floor Mapping: U.S. Geological Survey Open-File Report 99-439, 1 CD-ROM. (Also available on line at <http://pubs.usgs.gov/of/of99-439/start.htm>)
    Gutierrez, B.T., Butman, Bradford, and Blackwood, D.S., 2001, Photographs of the sea floor of western Massachusetts Bay, offshore of Boston, Massachusetts, July 1999: U.S. Geological Survey Open-File Report 00-427, 1 CD-ROM. (Also available on line at <http://pubs.usgs.gov/of/of00-427/>)
    Valentine, P.C., Middleton, T., and Fuller, S., 2001, Maps showing sea floor topography, sun-illuminated sea floor topography, and backscatter intensity of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts: USGS Open-File Report #00-410, 1 CD-ROM, scale 1:60,000. (Also available on line at <http://pubs.usgs.gov/of/of00-410/>)

    Person who carried out this activity:

    William Danforth
    U.S. Geological Survey
    Operational Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2274 (voice)
    (508) 457-2310 (FAX)
    bdanforth@usgs.gov

    Hours_of_Service: 8 a.m. to 5 p.m. EST
    Date: Feb-2007 (process 3 of 3)
    Image shifted 1/2 grid cell to northwest (using the ArcMap/Data Management Tools/Projections and Transformations/Raster/Shift tool) to correct for an error identified in the SwathEd gridding algorithm in 2007. World files corrected.

    Person who carried out this activity:

    William Danforth
    U.S. Geological Survey
    Operational Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2274 (voice)
    (508) 457-2310 (FAX)
    bdanforth@usgs.gov

    Data sources produced in this process:
    • mb_backpc10m.tif

  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?

    No attributes are associated with these data.

  2. How accurate are the geographic locations?

    These data were navigated with a Differential Global Positioning System (DGPS); they are accurate to +/- 3 meters, horizontally.

  3. How accurate are the heights or depths?

    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.

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

    These data are complete. No further processing and/or modifications will be made to these data.

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

    These data are logically consistent.

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 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.

  1. Who distributes the data set? (Distributor 1 of 2)

    Bradford Butman
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, Massachusetts 02543-1598
    USA

    (508) 548-8700 x2212 (voice)
    (508) 457-2309 (FAX)
    bbutman@usgs.gov

    Hours_of_Service: 8 a.m. to 5 p.m. EST
  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 these data have been used by the U.S. Geological Survey (USGS), U.S. Department of the Interior (DOI), no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. 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.
    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.

  1. Who distributes the data set? (Distributor 2 of 2)

    U.S. Geological Survey Information Services
    Box 25286 Denver Federal Center
    Denver, Colorado 80225-0046
    USA

    (303) 202-4700 (voice)
    (303) 202-4188 (FAX)

    Hours_of_Service: 8 a.m. to 5 p.m. Mountain Time
  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 these data have been used by the U.S. Geological Survey (USGS), U.S. Department of the Interior (DOI), no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. 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.
    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: 28-Mar-2007
Metadata author:
Bradford Butman
U.S. Geological Survey
Oceanographer
384 Woods Hole Road
Woods Hole, MA 02543-1598
USA

(508) 548-8700 x2212 (voice)
(508) 457-2310 (FAX)
bbutman@usgs.gov

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

Generated by mp version 2.9.1 on Wed Mar 28 12:51:08 2007