U.S. Geological Survey, 2006, CAPESOUTH_GEO4M_XYZ.TXT: ASCII formatted file of the 4-m bathymetry from the southern half of USGS Survey 98015 of the Sea Floor off Eastern Cape Cod (Geographic): Open-File Report 2005-1048, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.This is part of the following larger work.Online Links:
- <http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capesouth_geo4m_xyz.zip>
- <http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capesouth_geo4m_xyz.txt>
- <http://pubs.usgs.gov/of/2005/1048/htmldocs/data_catalog.htm>
- <http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/>
Poppe, L.J., Paskevich, V.F., Butman, B., Ackerman, S.D., Danforth, W.W., Foster, D.S., and Blackwood, D.S., 2006, Geological Interpretation of Bathymetric and Backscatter Imagery of the Sea Floor off Eastern Cape Cod, Massachusetts: Open-File Report 2005-1048, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
This is a Point data set.
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.
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.
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
To release the ASCII data file containing the 4-m bathymetry generated from USGS survey 98015 off eastern Cape Cod.
.
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).
(2) 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 predicted tides using the Xtide program <http://www.flaterco.com/xtide/xtide.html>), which generated predicted tides based on the harmonic coefficients for Chatham provided by the Xtide program.
(F.) Map the bathymetric soundings from each processed data file onto a Mercator grid using weigh_grid (a SwathEd utility) with node spacings and scale selected by the operator. The grid file (capesouth.r4) was a floating point binary file.
Person who carried out this activity:
(508) 548-8700 x2274 (voice)
(508) 457-2310 (FAX)
bdanforth@usgs.gov
Data sources produced in this process:
Data sources used in this process:
Data sources produced in this process:
Poppe, L.J., Foster, D.S., and Danforth, W.W., 2006, Character and distribution of exposed glaciodeltaic deposits off outer Cape Cod, Massachusetts, and their effects on hydrogeology and benthic habitats: Geo-Marine Letters v. 26, Springer, Germany.
Navigation was by differential GPS
All collected data were processed and used to produce this dataset.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Data are not to be used for navigation purposes.
Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
(508) 548-8700 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
Downloadable Data
Although this data set has 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.Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
| Data format: | The ASCII bathymetry (capesouth_geo4m_xyz.txt) and associated metadata. in format ASCII |
|---|---|
| Network links: |
<http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capesouth_geo4m_xyz.zip> <http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capesouth_geo4m_xyz.txt> <http://pubs.usgs.gov/of/2005/1048/htmldocs/data_catalog.htm> <http://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/> |
| Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
|
The user must have a program capable of reading and processing ASCII formated XYZ data files.
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov