Survey tracklines along which bathymetric data were collected with a SEA, SWATHplus interferometric sonar offshore of Massachusetts within northern Cape Cod Bay (CCB_BathTracklines EsriI Shapefile, Geographic, WGS84).

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Frequently anticipated questions:


What does this data set describe?

Title:
Survey tracklines along which bathymetric data were collected with a SEA, SWATHplus interferometric sonar offshore of Massachusetts within northern Cape Cod Bay (CCB_BathTracklines EsriI Shapefile, Geographic, WGS84).
Abstract:
These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHCMSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of sea-floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters of coastal Massachusetts, primarily in water depths of 3-30 meters deep. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (http://woodshole.er.usgs.gov/project-pages/coastal_mass/html/current_map.html). The data collected in the study area located in Northern Cape Cod Bay Massachusetts includes high-resolution geophysics (bathymetry, backscatter intensity, and seismic reflection), and ground validation (sediment samples, video tracklines, and bottom photographs). The data were collected during five separate surveys conducted between 2006 and 2008 and cover 480 square kilometers of the inner continental shelf. More information about the individual USGS surveys conducted as part of the northern Cape Cod Bay project can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpage: 06012: http://quashnet.er.usgs.gov/data/2006/06012/ 07001: http://quashnet.er.usgs.gov/data/2007/07001/ 07002: http://quashnet.er.usgs.gov/data/2007/07002/ 07003: http://quashnet.er.usgs.gov/data/2007/07003/ 08002: http://quashnet.er.usgs.gov/data/2008/08002/
  1. How might this data set be cited?
    U.S. Geological Survey, 2010, Survey tracklines along which bathymetric data were collected with a SEA, SWATHplus interferometric sonar offshore of Massachusetts within northern Cape Cod Bay (CCB_BathTracklines EsriI Shapefile, Geographic, WGS84).: Open-File Report 2010-1006, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D., Ackerman, Seth D., Baldwin, Wayne E., and Barnhardt, Walter A., 2010, Geophysical and Sampling Data from the Inner Continental Shelf: Northern Cape Cod Bay, Massachusetts.: Open-File Report 2010-1006, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.643264
    East_Bounding_Coordinate: -70.112566
    North_Bounding_Coordinate: 42.093436
    South_Bounding_Coordinate: 41.929450
  3. What does it look like?
    http://pubs.usgs.gov/of/2010/1006/GIS/browse_jpg/CCB_BathTracklines.jpg (JPEG)
    Thumbnail image of tracklines along which bathymetry was collected in the Cape Cod Bay Massachusetts survey area.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 16-Aug-2006
    Ending_Date: 07-May-2008
    Currentness_Reference:
    ground condition of four separate date ranges - 20060816 to 20060823; 20070429 to 20070503; 20070725 to 20070807; 20080429 to 20080507
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • String (585)
    2. What coordinate system is used to represent geographic features?
      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 D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    CCB_BathTracklines
    Tracklines for swath bathymetric systems (Source: USGS)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    survey
    WHCMSC field activity number (Source: USGS) Information unavailable from original metadata.
    vessel
    Name of the survey vessel used to collect the data (Source: USGS) Information unavailable from original metadata.
    linename
    Name of the survey line and raw data file that was collected along the line. For example "l34f2" is survey line (l) 34, File 2 (f2). (Source: USGS) Information unavailable from original metadata.
    Device
    Name of the sonar used to collect data along the survey line (Source: USGS) Information unavailable from original metadata.
    Mosaic
    Attribute to identify the trackline data that is included in the ccb_bath_5m grid (Source: USGS) Character string of width 4.
    LenthKM
    Length of polyline feature in kilometers (calculated using UTM Zone 19, WGS84). (Source: USGS)
    Range of values
    Minimum:0.04
    Maximum:18.61
    Units:kilometers (km)
    Year
    Year data were collected (Source: USGS) Characters string of width 10.
    JD
    The Julian Day the data were collected (Source: USGS) Characters string of width 10.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

The purpose of these data is to manage the trackline navigation and filenames of the 3,289 kilometers of raw bathymetry files collected using a Systems Engineering and Assessment (SEA) Ltd. SWATHplus interferometric sonar within the northern Cape Cod Bay survey area.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 1)
    Information unavailable from original metadata. Assumed to be USGS., unknown, Information unavailable from original metadata..

    Other_Citation_Details:
    This file had a source contribution, but no other source information. This information had to be modified to meet the standard.
    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Sonar Configuration: Bathymetry data were acquired using a Systems Engineering and Assessment Ltd. (SEA) SWATHplus interferometric sonar operating at 234 kHz (06012, 07001, 08002) or 117 kHz (07002). Survey lines were run at an average speed of 5 knots and were spaced 75-200 m apart to obtain overlapping swaths of data and full coverage of the seafloor. During USGS field activities 06012 and 07002, the SWATHplus transducers were mounted on a rigid pole on the starboard side of the R/V Megan Miller, about 2.6 m below the waterline. During 06012, a TSS DMS 2-05 motion reference unit was mounted directly above the sonar transducers and continuously recorded and sent vertical displacement (heave) and attitude (pitch and roll) of the vessel during acquisition to the SWATHplus software. During 06012 vessel heading was determined by a KVH compass that was corrected for magnetic variation of +15.583 degrees (from NOAA Chart number13246 36th ed., Mar. 10/01) during post processing. During 07002, a Coda Octopus F180 inertial-motion unit, mounted directly above the transducers, measured true heading, vertical displacement (heave) and attitude (pitch and roll) of the vessel during acquisition. Field activities 07001 and 08002: the SWATHplus transducers were mounted on a rigid pole on the bow of the R/V Rafael, about 0.5 m below the waterline. A Coda Octopus F180 inertial-motion unit, mounted directly above the transducers, measured true heading, vertical displacement (heave) and attitude (pitch and roll) of the vessel during acquisition. Navigation: Field activity 06012: Real-Time Kinematic (RTK) GPS navigation was used to determine the horizontal and vertical position (xyz) of the GPS antenna mounted directly above the SWATHplus transducers with sub-meter accuracy. The RTK-corrected coordinates were transmitted to the ship from a land-based RTK-GPS station established by the USGS at NOAA Tidal Station #8446009 in Brant Rock Harbor, MA. Field activities 07001, 07002, and 08002: Differential GPS (DGPS) navigation was used to determine the horizontal position (x,y) of the GPS antenna mounted directly above and forward (F180R primary antenna, 0.5 meters) of the SWATHplus transducers with +/- 1-2 meter accuracy. RTK-GPS was used to determine the vertical position of the Ashtech GPS antenna (z) with sub-meter accuracy. Vertical coordinates for all four surveys were referenced to Mean Lower Low Water (MLLW) using the offset between the North American Vertical Datum of 1988 (NAVD 88) and MLLW published for the tidal benchmark. Horizontal (x and y) and vertical (z) offsets between the transducers, motion sensor, and GPS antenna were precisely measured and recorded within the SWATHplus acquisition software (SEA Swath Processor (2005)), which established the motion sensor as the common reference point during data acquisition. Speed of Sound: Sound-velocity profiles were collected approximately every 2 hours by a hand-casted Applied MicroSystems SV Plus sound velocimeter. The depth of the transducers below the sea surface was measured and recorded within the SWATHplus acquisition software, and used as a reference point for deriving the acoustic ray path based on sound velocity profiles. Tides: During post-processing, soundings were referenced to local MLLW by using orthometric to chart datum offsets obtained from NOAA Tidal Station #8446009 at Brant Rock Harbor, Massachusetts. Data were processed and gridded by using the SEA SWATHplus Swath Processor (version 10.0) CARIS Hydrographic Information Processing System (HIPS version 6.1).
  2. How were the data generated, processed, and modified?
    Date: 2008 (process 1 of 9)
    Raw to Processed Conversion: Survey navigation information is stored within each raw (sxr) data file. Each raw SWATHplus bathymetric sonar file (sxr) was converted to a SWATHplus processed file (sxp) using SEA SWATHplus Swath Processor (ver. 3.05.19.0). Processing occurred in 2006, 2007, and 2008. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2008 (process 2 of 9)
    CARIS Processing: A new Computer Aided Resource Information System (CARIS) Hydrographic Information Processing System (HIPS) project (ver. 6.1) was created with projection information set to Universal Transverse Mercator (UTM) Zone 19, WGS84. Each SWATHplus processed file (sxp) was imported to the new CARIS project using the Import/Conversion Wizard. Navigation was checked and edited as needed using the Navigation Editor tool. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: Jan-2010 (process 3 of 9)
    A series of Perl and AWK programming scripts were used to extract and subsample the navigation fixes stored in the CARIS HIPS database. The processing flow for this step follows: A. Extract navigation for each line in CARIS HDCS directory using Perl script do_CARIS_nav2.pl (which runs the CARIS program printfnav for all the lines in the HDCS dir) and the grep statement below. (Extracted navigation file is tab-delimited in format YYYY-JD HH:MM:SS:FFF DD.LAT DD.LONG SSSSS_VVVVV_YYYY-JD_LLLL AR where YYYY=year, JD=Julian Day, HH=hour, MM=minute, SS=seconds, FFF=fractions of a second, DD.LAT=latitude in decimal degrees, DD.LONG=longitude in decimal degrees, SSSSS=survey name, VVVVV=vessel name, LLLL=linename, AR=accepted or rejected navigation fix) > grep Accepted combined.txt > greped_combined.txt. B. The files extracted from CARIS HIPS have 4-5 navigation fixes per second. Each file was subsampled to 1 fix per second by using AWK (see code below) to remove the fractions-of-a-second from the time column then grabbing the first occurrence of each second. > awk '{print $1" "substr($2,1,8)" "$3" "$4" "$5}' greped_combined.txt | awk '$2 != prev { print; prev = $2 }' > 2.CCB_NAV_awked.txt C. Checked that there were no additional spurious fixes outside the survey area using another series of AWK code (see code below), and reformatted for conversion from comma separated value (CSV) data to ESRI point feature class > awk -F" " '{if(substr($4,1,3)=="-70") print $0}' 2.* | awk -F" " '{if(substr($3,1,1)=="4") print $0}'| awk -f reformat_CARIS2Arc_CCB.awk > CCB_bathyNAV_all.csv Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
    Date: Jan-2010 (process 4 of 9)
    In ArcCatalog (version 9.3), navigation text (CCB_bathyNav_all.csv) was converted to a point feature class by right-clicking on the comma separated value text file -- Create Feature Class -- from XY table using the defined projection Geographic (Decimal_Degrees_WGS84.prj). {output file: XYCCB_bathyNAV_all.shp] Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
    Date: Jan-2010 (process 5 of 9)
    VAC Extras tool (version: 2.1 FeatConv - Points to Line v2; USGS in-house software) was then used within ArcMap (version 9.3) to convert the navigation points (XYCCB_bathyNAV_all.shp) to a temporary trackline shapefile (CCB_bathyNAV_all_trk.shp). The trackline shapefile was checked to ensure no spurious fixes. XTools Pro (version 5.3.0) for ArcGIS desktop was used to reorganize and add fields to the polyline shapefile's attribute table. Fields for device used to collect the data ('DEVICE'), survey vessel name ('Vessel'), and year ('YEAR') were added and populated using the table editor in ArcMap (version 9.3). Table attributes for the survey ("SURVEY') and Julian day ('JD') of data collection, were already populated but edited to be consistent with the other trackline shapefile in this report. The length field ('LENGTH_KM') was populated using 'Calculate Geometry' (Property=Length; Use coordinate system of the data frame=WGS 1984 UTM Zone 19N; Unit=Kilometers), which can be accessed by right-clicking on the attribute field name in the table view. (output file: CCB_BathTracklines.shp) Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 20-Nov-2015 (process 6 of 9)
    Edits to the metadata were made to fix any errors that MP v 2.9.30 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). The format of the time period of content and some process dates had to be fixed. This file had a source contribution, but no other source information. This information had to be modified to meet the standard. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 7 of 9)
    USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 18-Nov-2019 (process 8 of 9)
    Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 08-Sep-2020 (process 9 of 9)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Barnhardt, Walter A., Andrews, Brian D., and Butman, Bradford, 2006, High-Resolution Mapping of the Inner Continental Shelf: Nahant to Gloucester, Massachusetts: Open-File Report 2005-1293, U.S. Geological Survey, Reston, VA.

    Online Links:

    Ackerman, Seth D., Butman, Bradford, Barnhardt, Walter A., Danforth, William W., and Crocker, James M., 2006, High-Resolution Geologic Mapping of the Inner Continental Shelf: Boston Harbor and Approaches, Massachusetts: Open-File Report 2006-1008, U.S. Geological Survey, Reston, VA.

    Online Links:

    Barnhardt, Walter A., Andrews, Brian D., Ackerman, Seth D., Baldwin, Wayne E., and Hein, Christopher J., 2009, High-Resolution Geological Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts: Open-File Report 2007-1373, U.S. Geological Survey, Reston, VA.

    Online Links:

    Barnhardt, Walter A., Ackerman, Seth D., Andrews, Brian D., and Baldwin, Wayne E., 2010, Geophysical and Sampling Data from the Inner Continental Shelf: Duxbury to Hull, Massachusetts: Open-File Report 2009-1072, U.S. Geological Survey, Reston, VA.

    Online Links:


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    All attributes were checked in a consistent manner.
  2. How accurate are the geographic locations?
    Field activity 06012: The SWATHplus transducers were mounted on a rigid pole, approximately 2.6 m below the water line, along the starboard side of the R/V Megan T. Miller. Position data were provided by an Ashtech Z-Surveyor Extreme for real-time kinematic (RTK) navigation (an Ashtech BR2G Differential Global Positioning System (DGPS) was used as a backup navigation system) and recorded to the raw data files (SXR) via Swath Processor (version 2.07) acquisition software. During some portions of the survey, technical difficulties caused the GPS systems to malfunction and lose the "fixed" RTK signal. When this occurred, the navigation system defaulted to a "float" RTK, and then to a GPS (stand alone) signal, after which the navigation signal was lost completely. Surveying was halted until a reliable GPS signal was restored. A conservative estimate of positional accuracy is +/- 2 meters, but when the navigation system was providing the "fixed" RTK signal, positional accuracy is <1 m. Field activities 07001, 07002, and 08002: The SWATHplus transducers were mounted on a rigid pole from the bow of the R/V Rafael, approximately 0.5 m below the water line during surveys 07001 and 08001, and 2.6 m below the water line on the starboard side for survey 07002. Position data were recorded by Hypack software to Hypack raw files using an Ashtech Z-Surveyor Extreme for real-time kinematic (RTK) navigation, and an Ashtech BR2G for Differential Global Positioning System (DGPS) navigation. DGPS navigation from the primary F180 antenna was recorded to the raw sonar data files (SXR) via SWATHplus acquisition software. A conservative estimate of positional accuracy is +/- 2 meters.
  3. How accurate are the heights or depths?
    Based on SWATHplus interferometric sonar system specifications, vertical accuracy of the raw data may approximate 1% of water depth, which translates to 0.1 0.6 meters within the northern Cape Cod Bay survey area. RTK-GPS was used to establish water-level heights relative to Mean Lower Low Water (MLLW), providing decimeter-scale accuracies. Tide-correction was done in post-processing (see process steps). Refraction artifacts were minimized by acquiring a range of sound velocity profiles throughout the survey area to model the sound velocity structure of the water column. Changes in vessel draft due to fuel and water usage were not considered.
  4. Where are the gaps in the data? What is missing?
    Only the subsets of interferometric bathymetric sonar collected during field activities 06012 and 07001 that are within the study area in the northern Cape Cod Bay survey area south of Brant Rock, Massachusetts and have been included in this spatial dataset. This shapefile includes all bathymetric tracklines collected in the northern Cape Cod Bay survey area, however, not all of these tracklines were included in the final bathymetric grid published in this same report. Data collected along transit lines, east-west seismic tie lines, and other lines of poor quality were excluded from this grid. The " Mosaic" attribute in this shapefile identifies the 528 lines that were included and the 60 lines that were not included in the final grid.
  5. How consistent are the relationships among the observations, including topology?
    Any spurious data points were removed during processing. Duplicate names may exist for the linename attribute; however further querying the data by the "Survey", "Device", or "JD" attributes will distinguish a unique trackline for each record in this spatial dataset.

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 1)
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    bandrews@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. 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?
    • Availability in digital form:
      Data format: Survey tracklines for SWATHplus bathymetric data collected offshore of Massachusetts within northern Cape Cod Bay. in format SHP (version ArcGIS 9.3) ESRI polyline shapefile Size: 12
      Network links: http://pubs.usgs.gov/of/2010/1006/GIS/shapefile/CCB_BathTracklines.zip
      Media you can order: DVD-ROM (Density 4.75 Gbytes) (format UDF)
    • Cost to order the data: none

  5. What hardware or software do I need in order to use the data set?
    This zip file contains data available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have software capable of uncompressing the WinZip file and displaying the shapefile. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Brian Andrews
U.S. Geological Survey
Geographer
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2010-1006/CCB_BathTracklines.shp.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:20:26 2021