se_5mbath -Nahant to Gloucester, Swath Bathymetry of the South Essex Survey Area
Nahant to Gloucester, Swath Bathymetry of the South Essex Survey Area layer

Data format: Raster Dataset - ESRI GRID

File or table name: se_5mbath

Coordinate system: Universal Transverse Mercator

Theme keywords: U.S. Geological Survey, USGS, Coastal and Marine Geology Program, CMGP, Woods Hole Science Center, WHSC, Bathymetry, Seafloor, Marine Geology, Swath Bathymetry, Interferometric Sonar, ArcGIS Raster, field activity serial number RAFA03007, field activity serial number RAFA04002, oceans and estuaries, elevation, imageryBaseMapsEarthCover

Abstract: These data are high-resolution bathymetric soundings of the seafloor offshore of Massachusetts, from Nahant to Gloucester. Approximately 127 kmē of the inner shelf were mapped in the nearshore region between the 10m and 40-m isobath.

FGDC and ESRI Metadata:

Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.

Identification Information:


Citation:
Citation information:
Originators: Brian D. Andrews


Title:
se_5mbath -Nahant to Gloucester, Swath Bathymetry of the South Essex Survey Area
*File or table name: se_5mbath


Publication date: 2005
Geospatial data presentation form: raster digital data


Series information:
Series name: Open File Report
Issue identification: 2005-1293

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/2005/1293/gis/OFR_2005_1293/grids/se_5mbath.zip


Larger work citation:
Citation information:
Originators: Walter A. Barnhardt, Brian D, Andrews, Bradford Butman


Title:
High-Resolution Geologic Mapping of the Inner Continental Shelf: Nahant to Gloucester, Massachusetts


Publication date: 2006


Series information:
Series name: Open-File Report
Issue identification: 2005-1293

Publication information:
Publication place: Woods Hole Science Center, Woods Hole, Massachusetts
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program

Online linkage: http/pubs.usgs.gov/2005/1293/


Description:
Abstract:
These data are high-resolution bathymetric soundings of the seafloor offshore of Massachusetts, from Nahant to Gloucester.  Approximately 127 kmē  of the inner shelf were mapped in the nearshore region between the 10m and  40-m isobath.

Purpose:
These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center. High resolution bathymetry, backscatter intensity, and seismic profile data were collected over 127 kmē area covering a portion of the South Essex Ocean Sanctuary to characterize the surface and subsurface of the seafloor for regional geologic framework investigations.

Bathymetric data were collected during two different surveys. Survey RAFA03007 
began Monday, 22 Sep 2003 (JD267) and ended on Tuesday, 14 Oct 2003 (JD287). RAFA04002 began 17 Apr 2004 (JD 108) and ended on 2 May 2004 (JD123).

*Language of dataset: en


Time period of content:
Time period information:
Range of dates/times:
Beginning date: 20030922,20040412
Ending date: 20031015,20040507

Currentness reference:
ground condition

Status:
Progress: Complete
Maintenance and update frequency: None planned

Spatial domain:
Bounding coordinates:
West bounding coordinate: -70.937266
East bounding coordinate: -70.664555
North bounding coordinate: 42.575257
South bounding coordinate: 42.391023

Local bounding coordinates:
*Left bounding coordinate: 341000.000000
*Right bounding coordinate: 363000.000000
*Top bounding coordinate: 4715000.000000
*Bottom bounding coordinate: 4695000.000000

Keywords:
Theme:
Theme keywords: U.S. Geological Survey, USGS, Coastal and Marine Geology Program, CMGP, Woods Hole Science Center, WHSC, Bathymetry, Seafloor, Marine Geology, Swath Bathymetry, Interferometric Sonar, ArcGIS Raster, field activity serial number RAFA03007, field activity serial number RAFA04002
Theme keyword thesaurus: General

Theme:
Theme keywords: oceans and estuaries, elevation, imageryBaseMapsEarthCover
Theme keyword thesaurus: ISO 19115 Topic Category

Place:
Place keywords: Massachusetts Bay, Atlantic Ocean, Salem Sound, Nahant, Gloucester, South Essex Ocean Sanctuary
Place keyword thesaurus: General

Stratum:
Stratum keywords: Seafloor
Stratum keyword thesaurus: General

Temporal:
Temporal keywords: 2003, 2004
Temporal keyword thesaurus: General

Access constraints: None
Use constraints:
Data are not intended for navigational use.

These data should not be used at resolutions for which it is not intended.

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: Brian Andrews
Contact organization: U.S. Geological Survey
Contact position: Marine Geographer


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: 508-548-8700 x2348
Contact facsimile telephone: 508-457-2310


Contact electronic mail address: bandrews@usgs.gov


*Native dataset format: Raster Dataset
Native data set environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722


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Data Quality Information:


Logical consistency report:
These data have not been quantitatively compared to previous hydrographic data, although they generally agree with qualitative comparison of published NOAA charts.

Positional accuracy:
Vertical positional accuracy:
Vertical positional accuracy report:
Ship motion was recorded with a TSS DMS 2-05 Attitude Sensor, mounted on a head above the interferometric Submetrix 2000 Series transducers. Navigation was recorded using Real Time Kinematic Differential Global Positioning System (RTK-DGPS). The interferometric sonar is an angle-measuring system; depth accuracy decreases with increasing horizontal range. The combined angular accuracy of the Submetrix 2000 Series and the TSS DMS 2-05 attitude sensor is documented as 0.1 degrees. Assuming a constant angular accuracy, and using the International Hydrographic Standard (IHO) of a required 0.3 meter accuracy in < 30 meter water depth, all data collected within the survey fall within the IHO accuracy standards. However, vertical accuracy is also directly affected by the accuracy of both the navigation system and tidal measurements. RTK DGPS vertical accuracy is assumed to be 0.2 meters. Tidal elevations were derived from RTK -DGPS heights sent from a survey-specific base station at the Eastern Point Light House in Gloucester.

The RTK corrected signal was sent from a USGS survey-specific  base station at the lighthouse on Eastern Point Lighthouse. The base station occupied a DMA monument, however, the x, & y positions were calculated for that location using a 3 day average of 12 hour data sets using the Online Positioning User Service (OPUS, National Geodetic Survey) solution.  Tidal elevations were calculated from NOAA Tidal Station #8441841 using the same OPUS solution and then applied to the corrected elevations for the base station at Eastern Point Lighthouse.  Antenna heights were referenced to Mean Tidal Level (MTL), and later reduced to Mean Lower Low Water (MLLW) for easier comparison of NOAA nautical charts.

Lineage:
Process step:
Process description:
Bathymetric data were corrected for variations in the speed of sound throughout the water column; sound velocity profiles were acquired throughout the survey area using an Applied MicroSystems SVPlus Sound Velocimeter. These data were downloaded and reformatted to the required format needed for use within University of New Brunswick's Ocean Mapping Group (OMG) SwathEd multibeam processing software. The raw Submetrix 2000 Series data were "unraveled" and reformatted into the OMG format. This process creates several files on disk: 

1) bathymetric soundings
2) raw sidescan backscatter
3) navigation
4) parameter files describing the configuration of the system (i.e. offsets between motion reference unit and GPS antenna, etc). This process also incorporates the sound velocity profiles in order to properly trace the rays given the structure of the water column.

Process step:
Process description:
The OMG formatted bathymetric data were then graphically edited using the SwathEd multibeam processing software. This enabled editing on a "ping-by-ping" basis, both in the across- and along-track dimension. Spurious or erroneous data were removed. The navigation data were also graphically examined for each line of data.

Process step:
Process description:
Soundings data were gridded using the weigh_grid routines from Swathed. Soundings were corrected to mean lower low water during the weigh_grid operation using the real time kinematic differential Global positioning navigation files.

The final weigh_grid parameters used were:
weigh_grid -omg -coeffs -butter -lambda 5 -cutoff 20  

Max_incidence angle was not used in most lines to use all of the swath. Only lines from rough days or big heave were gridded with a small incidence angle to maximize the good data from adjacent lanes and reduce the noisy data.

Process step:
Process description:
OMG grid format (*.r4) converted to ASCII raster format using the script UTMr4toAscii for import to ArcGIS 9.0

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Spatial Data Organization Information:


Direct spatial reference method: Raster


Raster object information:
*Image format: ESRI GRID
*Number of bands: 1


Row count: 4000
Column count: 4400
Vertical count: 1


*Cell size X direction: 5.000000
Cell size X units: meters
*Cell size Y direction: 5.000000
Cell size Y units: meters


*Bits per pixel: 32
*Pyramid layers: TRUE
*Image colormap: FALSE
*Compression type: Default


Raster object type: Grid Cell
*Raster display type: matrix values
*Raster origin: Upper Left


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Spatial Reference Information:


Horizontal coordinate system definition:
Coordinate system name:
*Projected coordinate system name: WGS_1984_UTM_Zone_19N
*Geographic coordinate system name: GCS_WGS_1984

Planar:
Grid coordinate system:
*Grid coordinate system name: Universal Transverse Mercator
Universal Transverse Mercator:
*UTM zone number: 19
Transverse mercator:
*Scale factor at central meridian: 0.999600
*Longitude of central meridian: -69.000000
*Latitude of projection origin: 0.000000
*False easting: 500000.000000
*False northing: 0.000000

Planar coordinate information:
Planar coordinate encoding method: row and column
Coordinate representation:
Abscissa resolution: 5.000000
Ordinate resolution: 5.000000
Planar distance units: meters

Geodetic model:
Horizontal datum name: D_WGS_1984
Ellipsoid name: WGS_1984
Semi-major axis: 6378137.000000
Denominator of flattening ratio: 298.257224

Vertical coordinate system definition:
Depth system definition:
Depth datum name: Mean lower low water

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Entity and Attribute Information:


Detailed description:
Entity type:

Overview description:
Dataset overview:
Swath bathymetry in ESRI GRID format.  Data values represent depth in meters referenced to mean lower low water (MLLW).

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Distribution Information:


Distributor:
Contact information:
Contact person primary:
Contact person: Brian Andrews
Contact organization: U.S. Geological Survey, Woods Hole Science Center
Contact position: Marine Geographer


Contact address:
Address type: mailing and physical address
Address:
384 Woods Hole Rd.
City: Woods Hole
State or province: MA
Postal code: 02543
Country: USA

Contact voice telephone: 508-548-8700 x2348


Contact electronic mail address: bandrews@usgs.gov


Resource description: Downloadable Data


Distribution liability:
Although this data set has been used by the U.S. Geological Survey (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.

Standard order process:
Digital form:
Digital transfer information:
Format name: ARCG
Format version number: ArcGIS 9.0
Format specification:
ESRI Raster GRID format
File decompression technique: no compression applied
Transfer size: 70.519
*Dataset size: 70.520

Digital transfer option:
Online option:
Computer contact information:
Network address:
Network resource name: http://pubs.usgs.gov/of/2005/1293/gis/OFR_2005_1293/grids/se_5mbath.zip

Offline option:
Offline media: DVD-ROM
Recording format: UDF
Compatibility information:
None

Fees: None


Technical prerequisites:
These data are available in Environmental Systems Research Institute (ESRI) GRID format. The user must have software capable of importing and processing the data file.


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Metadata Reference Information:


Metadata date: 20051005


*Language of metadata: en


Metadata contact:
Contact information:
Contact person primary:
Contact person: Brian Andrews
Contact organization: U.S. Geological Survey
Contact position: Marine Geographer


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: 508-548-8700 x2348
Contact facsimile telephone: 508-457-2310


Contact electronic mail address: bandrews@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

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Binary Enclosures:


Thumbnail:
Enclosure type: Picture


Nahant to Gloucester, Swath Bathymetry of the South Essex Survey Area layer

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