2010-047-FA_Boomer_cdp500.shp - CDP navigation at 500 trace intervals for multichannel boomer seismic-reflection data collected by the U.S. Geological Survey in Vineyard Sound and Buzzards Bay, MA, 2010 (Esri point shapefile, Geographic WGS 84)

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Frequently anticipated questions:

What does this data set describe?

Title:
2010-047-FA_Boomer_cdp500.shp - CDP navigation at 500 trace intervals for multichannel boomer seismic-reflection data collected by the U.S. Geological Survey in Vineyard Sound and Buzzards Bay, MA, 2010 (Esri point shapefile, Geographic WGS 84)
Abstract:
These data were collected under a cooperative agreement between 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 seafloor 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 2-30 meters. 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 this study area are located in both Buzzards Bay and Vineyard Sound and are primarily in the shallow water areas around the eastern Elizabeth Islands and Martha's Vineyard, Massachusetts. The data include high resolution bathymetry, acoustic-backscatter intensity, sound velocity in water, seismic-reflection profiles, and navigation data. These data were collected during several cruises between 2007 and 2011 onboard the R/V Rafael using the following equipment: an SEA Ltd SwathPlus interferometric sonar (234 kHz), Klein 3000 dual frequency sidescan sonar, a boomer source and Geometrics 8-channel GeoEel streamer, a Knudsen 3200 subbottom profiling system, and 4 GPS antennae. More information about the cruises conducted as part of the project: Geologic Mapping of the Seafloor Offshore of Massachusetts can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpages: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-013-FA> <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2009-068-FA> <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2007-039-FA><http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-100-FA><http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-047-FA>
  1. How should this data set be cited?

    U.S. Geological Survey, 2013, 2010-047-FA_Boomer_cdp500.shp - CDP navigation at 500 trace intervals for multichannel boomer seismic-reflection data collected by the U.S. Geological Survey in Vineyard Sound and Buzzards Bay, MA, 2010 (Esri point shapefile, Geographic WGS 84): Open-File Report 2013-1020, 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.

    Pendleton, Elizabeth A., Andrews, Brian D., Danforth, William W., and Foster, David S., 2013, High-Resolution Geophysical Data From Sand Shoals of Vineyard Sound and the Sea Floor Surrounding the Eastern Elizabeth Islands, Massachusetts: Open-File Report 2013-1020, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -70.881762
    East_Bounding_Coordinate: -70.608493
    North_Bounding_Coordinate: 41.677964
    South_Bounding_Coordinate: 41.361526

  3. What does it look like?

    <http://pubs.usgs.gov/of/2013/1020/GIS_catalog/tracklines/2010-047-FA_boomer_500cdp.png> (PNG)
    PNG of multichannel boomer seismic reflection 500 interval CDP navigation points

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

    Beginning_Date: 07-Jul-2010
    Ending_Date: 19-Jul-2010
    Currentness_Reference:
    No data were recorded on 20100710 to 20100713 due to weather conditions

  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 Point data set. It contains the following vector data types (SDTS terminology):

      • Entity point (262)

    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?

    2010-047-FA_Boomer_cdp500
    Tracklines for seismic profiles (Source: U.S. Geological Survey)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    Line_1
    Survey line name (Source: U.S. Geological Survey)

    String

    CDP
    The CDP (reflection mid-point) number calculated based on the geometry of the seismic system (Source: U.S. Geological Survey)

    Range of values
    Minimum:95
    Maximum:17063
    Units:trace
    Resolution:1

    Entity_and_Attribute_Overview:
    The first CDP value for each line usually begins with 95-100, instead of 1, which is the case if this were shot numbers. An offset of 100 was added to the beginning of the CDP value to avoid negatives introduced by the trace gathering process.

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?

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

Why was the data set created?

CDP navigation at intervals of 500 and beginning and ending CDP values for each seismic profile were generated in order to incorporate the seismic data into Geographic Information System (GIS) projects and data archives utilizing HTML. These CDP navigation data represent approximately 140 km of multichannel boomer seismic data collected with a GeoAcoustics boomer source and Geometrics 8-channel GeoEel streamer.

How was the data set created?

  1. From what previous works were the data drawn?

    USGS (source 1 of 1)
    Type_of_Source_Media: disc
    Source_Contribution:
    Approximately 170 km of high-resolution multichannel boomer seismic-reflection profiles were collected. The Applied Acoustics boomer source was towed on the starboard side of the RV Rafael, 10 meters aft of the GPS antenna, and was fired at a power level of 100 joules at 1-second intervals with trace lengths of 250 milliseconds and 1000 samples per trace. The Geometrics GeoEel, eight-channel liquid filled digital streamer was towed from the port side of the vessel, and the center of the first channel of the active section was 22 meters aft of the boomer source. The streamer had a group interval of 3.125 meters connected to Geometrics Streamer Power Supply Unit (SPSU). Data acquired in Geometrics SEG-D format on Windows PC controller system using Geometrics CNT-1 software. The sample interval was 0.25 ms.

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

    Date: 05-Jan-2011 (process 1 of 6)
    A SIOSEIS seismic processing software script was used as follows: the raw SEG-D shot files were read with the process SEGDDIN specifying geometrics format; for Julian days 193 to 194, the process HEADER was used to insert time of day into the SEG-Y header based on the start and end times recorded in the HYPACK files and what was entered in the survey log; the process GEOM was used to describe the shot and streamer geometries and to calculate the reflection point (CDP) numbers used to gather (sort traces by CDP) the seismic line; the process GEOM was used to set the shot-receiver distance into the trace header of every trace; GEOM type 6 was specified (because positions were absent or bad in the header), which computes a distance from last shot (DFLS) for each shot based on the shot time in the header and the navigation from an ASCII file containing time and position; the ASCII shot navigation file was derived from the HYPACK navigation data and merged with shot point files with the Unix join command; a normal move out (NMO) applied a travel time correction to each trace based on offset and a velocity of 1500 m/s; process GATHER was used to sort the shot order traces in to traces sorted by the CDP numbers computed by the process GEOM; lastly, the CDP trace gathers were written with the process DISKOX in SEG-Y rev. 1, IEEE floating point format.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Suvey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2271 (FAX)
    dfoster@usgs.gov

    Date: 05-Jan-2010 (process 2 of 6)
    SIOSEIS script was used to stack the CDP gathers, apply a bandpass filter and automatic gain control. The process DISKIN read the CDP sorted SEG-Y file and renumbered CDP starting at one and incremented CDP number by one. The process STACK was used to sum traces, compute the average amplitude for each trace sample, and write the computed samples to one trace. The trace header values of the first trace in the gather were used for the stacked trace. The process FILTER applied a zero-phase bandpass frequency domain filter between 600 and 2000 Hz with a slope of 48 decibel per octave slope. The process AGC applied an automatic gain control (AGC) with a window length of 5 ms. The computed multiplier for each AGC window was reduced by fifty percent. Lastly, the processed stacked traces were written to disk with the process DISKOX in SEG-Y rev. 1 , IEEE floating point format.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Date: 05-Jan-2010 (process 3 of 6)
    A Seismic Unix script was used to read the trace headers of the stacked SEG-Y files and write CDP, source X and Y, year, day, hour minute, seconds only where the original channel number was equal to one (the channel closest to the source). Some CDP gathers did not contain a trace with channel one in the header and were eliminated. The coordinates represent the position of the GPS antenna, which has a constant offset of 10 meters to the source. The source to receiver offset was 22 meters. Half the distance between source and receiver represents the location of the common reflection point. A layback correction of 21 meters was applied to the navigation using an AWK script written by Wayne Baldwin, USGS. An AWK script was used to format the trace navigation with corrected layback positions in a comma delimited file.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Date: 16-Apr-2013 (process 4 of 6)
    Text files created in the previous step were concatenated into a comma-delimited text file, then imported into ArcMap (version 9.3.1) using 'Create Feature Class from XY Table' and saved as points (UTM Zone 19, WGS 84) in the Esri shapefile format.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Date: 16-Apr-2013 (process 5 of 6)
    The shapefile created in the previous step was converted from points to polylines using VAC Extras Points to Line v2. The 'Line_1' field was used to define which points were used to generate each polyline feature.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Date: 16-Apr-2013 (process 6 of 6)
    Using ArcToolbox, Linear Referencing Tools, a CDP navigation file was created with points for CDP at even intervals of 500 and with start and end CDP values. First, Create Routes was used to create a polyline calibrated shapefile using the Line field as the Route Identifier and Length as the Measure Source. Calibrate Routes used the output from Create Routes with Line as the Route Identifier Field and the CDP point file for all unique fixes described in process step 4. The Point Identifier Field was Line, the Measured Field was CDP and the Measure Calculation Method was Measures. This created a calibrated polyline shapefile. Hatches were added at the beginning and end of each line, as well as at 500 CDP spacing. This was done in ArcMap 9.3 by opening the layer properties and selecting the Hatches tab. Create a hatch interval of 500 for the Hatch Class, then for Hatch Def(1) place a marker hatch every 1 hatch interval. From the Hatch Class -- Add a Hatch Definition - Add End Hatch Definition and set these to a marker Hatch. By displaying the labels for both Hatch Definitions, a quick comparison between the hatches and the unique trace navigation makes sure things are lining up right. Within ArcMap 9.3 - by going to Tools - Customize - Commands and scrolling down to the Category "Linear Referencing", the icon for the command "Convert Hatches to Graphics can be added to a toolbar. Once this is done, that tool can be used to convert the hatches to graphics. The graphics were converted to a shapefile using XTools Pro version 7.1. XTools Pro - Feature Conversions - Convert Graphics to Shapes. ArcToolbox - Linear Referencing Tools - Locate Features Along Route used the shapefile converted from graphics with input route features; Lines as Route Identifier Field, and 5 meters as Search Radius. A DBF file was output with Line as Route Identifier Field, point as Event Type, and CDP as Measure Field. The rest of options at default were checked. Using ArcMap 9.3 - ArcToolbox - Linear Referencing Tools - Make Route Event Layer to create an event feature. The input used the following parameters: input route features: the output from Calibrate Routes was the Input Route Features; Lines was the Route Identifier Field , input event table; the output from Locate Features Along Route was used for the Input Event Table; Line was the Route Identifier Field; Point was the Event Type; CDP was the Measure Field. The rest of the option left at default values. The event layer was converted to a shapefile in ArcMap 9.3 by exporting the data (right mouse click on event layer, Data, Export Data) to a temporary shapefile. The temporary shapefile was sorted within ArcMap 9.3 using VAC Extras version 2.1 (an extension written by the USGS in Woods Hole) to sort the shapefile: VAC Extras - FeatConv - Table Sort with the CDP file sorted based on Line and CDP. Line was set as the primary sort field, ascending order. CDP was set as the secondary sort field - ascending order. Output to 2010-047-FA_Boomer_cdp500.shp. Finally, ArcToolbox was used to reproject from UTM projection to Geographic coordinate system.

    Person who carried out this activity:

    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Data sources used in this process:
    • 2010-100-FA_Boomer_trackpoints.shp
    • 2010-100-FA_Boomer_tracklines.shp

    Data sources produced in this process:

    • 2010-100-FA_Boomer_sht500.shp

  3. What similar or related data should the user be aware of?

    Henkart, Paul, 2007, SIOSEIS: Scripps Institution of Oceanography, University of California - San Diego, LaJolla, CA.

    Online Links:

    Norris, Michael W., and Faichney, Alan K., 2002, SEGY Rev.1 Data Exchange Format1: Society of Exploration Geophysicists, Tulsa, OK.

    Online Links:

    Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Digital Field Tape Format Standards -- SEG-D: Society of Exploration Geophysicists, Tulsa, OK.

    Online Links:

    Stockwell, John, 2008, Seismic Uni*x: Center for Wave Phenomena - Colorado School of Mines, Golden, CO.

    Online Links:

    Andrews, B.D., Ackerman, S.D., Baldwin, W.E., Foster, D.S., and Schwab, W.C., 2013, High-Resolution Geophysical Data From the Inner Continental Shelf at Vineyard Sound, Massachusetts: Open-File Report 2012-1006, U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    Ackerman, S.D., Andrews, B.D., Foster, D.S., Baldwin, W.E., and Schwab, W.C., 2013, High-Resolution Geophysical Data from the Inner Continental Shelf: Buzzards Bay, Massachusetts: Open-File Report 2012-1002, U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Pendleton, E.A., Twichell, D.C., Foster, D.S., Worley, C.R., Irwin, B.J., and Danforth, W.W., 2012, High-Resolution Geophysical Data From the Sea Floor Surrounding the Western Elizabeth Islands, Massachusetts: Open-File Report 2011-1184, U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

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

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    The navigation for these data were acquired with an Communications Systems International (CSI), Inc. LGBX Pro Differential Global Positioning System (DGPS) receiver and an antenna mounted on the cabin of the R/V Rafael. All DGPS data are referenced to WGS 84. The Geometrics CNT-1 acquisition software logged the navigation coordinates (in arcseconds) to individual trace headers. Layback distance between the CSI antenna and the source and receiver were calculated in postprocessing. The resulting horizontal accuracy is assumed to be +/- 2 m; however, inaccuracies likely exceed this value due to uncertainty of azimuths calculated in the layback correction.

  3. How accurate are the heights or depths?

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

    This shapefile represents the 500 CDP interval and start and end point navigation for all the seismic lines collected on this cruise. No data were collected on Julian days 195 to 197 due to weather conditions.

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

    Processed seismic CDP navigation data were generated for inclusion in a GIS. Quality control was conducted during processing and points were checked to make sure they were viable fixes. File naming for Julian days 193 to 194 is x_yz, where x is the Julian Day and y is the time of day in hours, and z is the time of day in minutes with an implied decimal value of one. Note the time was based on system time and not GPS time for Julian days 193 to 194. A time server was installed for Julian days 198 to 200 and system time was synced with GPS time. For Julian days 198 to 200 file names is x_lyfz where x is Julian day, y is the survey line number, and z is the file number within the survey line.

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 as the originator of the dataset.

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

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2259 (voice)
    508-457-2310 (FAX)
    ependleton@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?

  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) polyline shapefile format and comma separated-value text (CSV). The user must have ArcGIS or ArcView 3.0 or greater software to read and process 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. The CSV file can be read opened with any text editing software.

Who wrote the metadata?

Dates:
Last modified: 16-Apr-2013
Metadata author:
David S. Foster
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA 02543-02543-1598
USA

508-548-8700 x2271 (voice)
508-457-2310 (FAX)
dfoster@usgs.gov

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

Generated by mp version 2.9.21 on Wed Oct 30 14:54:51 2013