Tracklines of a multibeam survey of the sea floor southwest of Montauk Point, New York, in 1998 (polyline shapefile, geographic, WGS 84)

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Frequently anticipated questions:

What does this data set describe?

Title:
Tracklines of a multibeam survey of the sea floor southwest of Montauk Point, New York, in 1998 (polyline shapefile, geographic, WGS 84)
Abstract:
Surveys of the bathymetry and backscatter intensity of the sea floor south of Long Island, New York, were carried out in November 1998 using a Simrad EM1000 multibeam echosounder mounted on the Canadian Coast Guard ship Frederick G. Creed. The purpose of the multibeam echosounder surveys was to explore the bathymetry and backscatter intensity of the sea floor in several areas off the southern coast of Long Island along the 20-meter isobath. Survey areas offshore of Fire Island Inlet, Moriches Inlet, Shinnecock Inlet, and southwest of Montauk Point were about 1 kilometer (km) wide and 10 km long. The area was mapped by the U.S. Geological Survey with support from the Canadian Hydrographic Service and the University of New Brunswick.
Supplemental_Information:
Other data sets from this survey may be found in Butman and others (2016) (see larger work citation).
  1. How might this data set be cited?
    U.S. Geological Survey, 2016, Tracklines of a multibeam survey of the sea floor southwest of Montauk Point, New York, in 1998 (polyline shapefile, geographic, WGS 84): data release DOI:10.5066/F7Z899GG, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Butman, Bradford, Danforth, William W., John E. Hughes Clarke, Signell, Richard P., and Schwab, William C., 2016, Bathymetry and backscatter intensity of the sea floor south of Long Island, New York: data release DOI:10.5066/F7Z899GG, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -72.265335
    East_Bounding_Coordinate: -72.129548
    North_Bounding_Coordinate: 40.938358
    South_Bounding_Coordinate: 40.877317
  3. What does it look like?
    mont_nav_browse.jpg (JPEG)
    Image of tracklines of a multibeam survey of the sea floor southwest of Montauk Point, New York. File is located in the compressed zip file.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 07-Nov-1998
    Ending_Date: 08-Nov-1998
    Currentness_Reference:
    ground condition
  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 (22)
    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?
    mont_nav.shp
    Shapefile showing the tracklines for the 1998 multibeam survey southwest of Montauk Point, New York (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.
    Linenum
    Trackline number assigned by USGS (Source: USGS)
    Range of values
    Minimum:3040
    Maximum:3061
    Lon
    Longitude at start of line (Source: USGS)
    Range of values
    Minimum:-72.26
    Maximum:-72.13
    Lat
    Latitude at start of line (Source: USGS)
    Range of values
    Minimum:40.87
    Maximum:40.93
    Year
    Year at start of line (Source: USGS)
    Range of values
    Minimum:1998
    Maximum:1998
    JulDay
    Julian Day (day from beginning of year) at start of line (Source: USGS)
    Range of values
    Minimum:311
    Maximum:312
    Hour
    Hour at start of line (Source: USGS)
    Range of values
    Minimum:0
    Maximum:23
    Minute
    Minute at start of line (Source: USGS)
    Range of values
    Minimum:3
    Maximum:56
    Second
    Second at start of line (Source: USGS)
    Range of values
    Minimum:2
    Maximum:58
    Entity_and_Attribute_Overview:
    The attributes are the USGS assigned line number, and the latitude, longitude, and time (year, Julian day, hour, minute, second) at the start of line.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

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?
    U.S. Geological Survey
    Attn: Bradford Butman
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA
    USA

    508-548-8700 x2212 (voice)
    bbutman@usgs.gov

Why was the data set created?

This data release makes multibeam echosounder data from the 1998 survey of the sea floor southwest of Montauk Point, New York, available in digital form. The navigation shapefile shows how the survey was carried out along tracklines running northeast-southwest approximately parallel to the local bathymetry and spaced about 100 m apart. The tracklines also can be used to identify data collected directly below the ship (at nadir).

How was the data set created?

  1. From what previous works were the data drawn?
    none (source 1 of 1)
    Service, Canadian Hydrographic, Danforth, William W., and John E. Hughes Clarke, Unpublished Material, raw navigation data.

    Type_of_Source_Media: disc
    Source_Contribution:
    The multibeam data were collected with a Simrad EM1000 multibeam echosounder mounted on the starboard pontoon of the Canadian Coast Guard ship Frederick G. Creed. The multibeam system utilizes 60 electronically-aimed receive beams spaced at intervals of 2.5 degrees that insonify a strip of sea floor up to 7.5 times the water depth. The horizontal resolution of the beam on the sea floor is approximately 10 % of the water depth. Vertical resolution is approximately 1 % of the water depth. Data were collected along tracklines oriented approximately northeast-southwest, parallel to the local isobaths, and spaced about 100 m apart. The frequency of the sonar was 95 kHz. Sound velocity profiles were obtained and input into the Simrad processing system to correct for refraction. Navigation was by means of differential GPS. Operation of the Simrad EM1000 was carried out by hydrographers of the Canadian Hydrographic Service. The data were collected on Woods Hole Coastal and Marine Science Center field activity 1998-015-FA.
  2. How were the data generated, processed, and modified?
    Date: 2010 (process 1 of 4)
    Reformat ASCII navigation data collected by the DGPS receiver into an Excel csv formatted ASCII file using the UNIX awk utility. Spacing between points in the trackline is defined by time (1-second intervals). Person who carried out this activity:
    U.S. Geological Survey
    Attn: William W. Danforth
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA
    USA

    508-548-8700 x2274 (voice)
    wdanforth@usgs.gov
    Data sources produced in this process:
    • mont_nav.shp
    Date: 2014 (process 2 of 4)
    1. Import the csv file as points into ArcGIS using the Import XY data under the tools menu. 2. Export the point data to a shapefile by right clicking on the point data in the data view window and selecting the Export Data function. 3. Reformat the point shapefile into a line shapefile using the VAC Extras tool -> FeatConv -> Points to line v2 Person who carried out this activity:
    U.S. Geological Survey
    Attn: William W. Danforth
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA
    USA

    508-548-8700 x2274 (voice)
    wdanforth@usgs.gov
    Date: 20-Jul-2018 (process 3 of 4)
    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: 10-Aug-2020 (process 4 of 4)
    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?
    Schwab, W.C., Thieler, E.R., Denny, J.F., and Danforth, W.W., 2000, Seafloor sediment distribution off southern Long Island, New York: Open-File Report 00-243, 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?
  2. How accurate are the geographic locations?
    These data were navigated with a Differential Global Positioning System (DGPS); they are accurate to +/- 3 meters, horizontally.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This shapefile contains all edited tracklines from 1998 multibeam survey southwest of Montauk Point, New York. Other data sets collected offshore of Long Island, New York, on WHCMSC field activity 1998-015-FA may be found in Butman and others (2016) (see larger work citation).
  5. How consistent are the relationships among the observations, including topology?
    All navigation data were processed in the same manner. Navigation data were edited on-screen using the SwathEd routine jview to remove undesirable points, including turns at the ends of survey lines. Jview also rejects stray GPS fixes outside of the survey area, as set by the operator (see process steps for bathymetry). The Long Island surveys were assigned a block of line numbers beginning with 3000. GPS position data began to degrade on line 3045 and went out completely on line 3047. GPS data were regained on line 3048. The loss of navigation resulted in a data offset on lines 3045-3047. The offset is not corrected.

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 none
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? mont_nav.zip: contains mont_nav.shp, other shapefile components, and FGDC-compliant metadata (CSDGM format).
  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?
    The shapefile of navigation is compressed into a WinZip (version 14) file (mont_nav.zip). To use these data, the user must have software capable of uncompressing the zip file and ArcGIS or another GIS application package capable of viewing the data.

Who wrote the metadata?

Dates:
Last modified: 19-Mar-2024
Metadata author:
U.S. Geological Survey
Attn: Bradford Butman
Woods Hole Coastal and Marine Science Center
Woods Hole, MA
USA

508-548-8700 x2212 (voice)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240319)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_F7Z899GG/mont_nav_meta.faq.html>
Generated by mp version 2.9.51 on Wed Jun 26 15:25:02 2024