U.S. Geological Survey, 2003, Sea Floor Topography and Backscatter Intensity of the Hudson Shelf Valley Region.: U.S. Geological Survey, Woods Hole, MA.This is part of the following larger work.Online Links:
Butman, Bradford, Gutierrez, Benjamin T., ten Brink, Marilyn Buchholtz, Schwab, William C., Blackwood, Dann S., Mecray, Ellen L., and Middleton, Tammie J., 20030000, Photographs of the Sea Floor Offshore of New York and New Jersey: Open File Reports (OFR) 01-470, U.S. Geological Survey, Reston, VA.Online Links:
This is a Raster data set. It contains the following raster data types:
Planar coordinates are encoded using row and column
Abscissae (x-coordinates) are specified to the nearest 12
Ordinates (y-coordinates) are specified to the nearest 12
Planar coordinates are specified in meters
The ellipsoid used is World Geodetic System 84.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257.
Multibeam data collected by the U.S. Geological Survey, Bradford Butman principal investigator. Parts of the data presented here are published in Butman and others (1998) (USGS Open-File Report 98-616; online at <https://pubs.usgs.gov/of/of98-616/>) and Butman and others (2002) (USGS Open-File Report 00-503; online at <https://pubs.usgs.gov/of/of00-503/>). Publication of a final data set planned for 2003.
U. S. Geological Survey
c/o Bradford Butman
Oceanographer
384 Woods Hole Rd
Woods Hole, MA 02543-1598
USA
508.457.2212 (voice)
508-457-2309 (FAX)
bbutman@usgs.gov
- Hours_of_Service: 8 a.m. - 5 p.m.
These preliminary data are included in this publication to provide bathymetry and backscatter intensity for maps showing the locations of images and samples obtained in the New York Bight. THIS DATA SET IS PRELIMINARY; PUBLICATION OF A FINAL DATA SET IS PLANNED IN 2003.
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.
(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.
Additional processing in the laboratory included adjusting the bathymetric observations to mean sea level using predictions of the ADCIRC tidal model (see Westerink, J.J., R.A. Luettich, Jr. and J. Muccino, 1994, "Modeling Tides in the Western North Atlantic Using Unstructured Graded Grids", Tellus, 46a(2):178-199.)
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 sea level, referenced to the ADCIRC model.
Person who carried out this activity:
William Danforth
U.S. Geological Survey
Operational Geologist
384 Woods Hole Road
Woods Hole, MA 02543-1598
USA
508.548.8700x2274 (voice)
508.457.2310 (FAX)
bdanforth@usgs.gov
- Hours_of_Service: 8 a.m. to 5 p.m. EST
No attributes are associated with these data.
These data were navigated with a Differential Global Positioning System (DGPS); they are accurate to +/- 3 meters, horizontally.
These data have been corrected for vessel motion (roll, pitch, heave, yaw). They have been corrected for tidal offsets using the sea level predicted using the ADCIRC tidal model. Additional corrections will be made. The vertical resolution of the Simrad EM-1000 multibeam echosounder is about 1 % of water depth.
These data are prelimary. Additional processing will be carried out to correct to mean low water, and to correct projection issues.
These data are logically consistent.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- This information is not for navigational purposes. THE MULTIBEAM DATA ARE PRELIMINARY; PUBLICATION OF A FINAL CORRECTED DATA SET IS PLANNED IN 2003.
Bradford Butman
U.S. Geological Survey
Oceanographer
384 Woods Hole Road
Woods Hole, Massachusetts 02543-1598
USA
508.548.8700x2212 (voice)
508.457.2309 (FAX)
bbutman@usgs.gov
- Hours_of_Service: 8 a.m. to 5 p.m. EST
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.
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
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.
Brad Butman
U.S. Geological Survey
Oceanographer
384 Woods Hole Road
Woods Hole, MA 02543-1598
508.548.8700x2212 (voice)