Bathymetry tracklines collected in the Belfast Bay, Maine pockmark field using a SWATHplus-M interferometric sonar in 2006 and 2008, by the U.S. Geological Survey (Esri polyline shapefile, WGS 84)

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• 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?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   U.S. Geological Survey, 20201210, Bathymetry tracklines collected in the Belfast Bay, Maine pockmark field using a SWATHplus-M interferometric sonar in 2006 and 2008, by the U.S. Geological Survey (Esri polyline shapefile, WGS 84): data release DOI:10.5066/P90QQCOR, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

   Online Links:

   • https://doi.org/10.5066/P90QQCOR
   • https://www.sciencebase.gov/catalog/item/5f5f968d82ce3550e3bff24a

   This is part of the following larger work.
   Andrews, Brian D., Danforth, William W., Brothers, Laura L., and Barnhardt, Walter A., 2020, High-resolution geophysical data collected in the Belfast Bay, Maine pockmark field in 2006, 2008, and 2009 by the U.S. Geological Survey: data release DOI:10.5066/P90QQCOR, U.S. Geological Survey, Reston, Virginia.

   Online Links:

   • https://doi.org/10.5066/P90QQCOR
   • https://www.sciencebase.gov/catalog/item/5f59214c82cefd9f2082c15e

   Other_Citation_Details:

   Suggested citation: Andrews, B.D., Danforth, W. W., Brothers, L.L., Barnhardt, W. A., 2020, High-resolution geophysical data collected in the Belfast Bay, Maine Pockmark Field in 2006, 2008, and 2009 by the U.S. Geological Survey: U.S. Geological Survey data release, https://doi.org/10.5066/P90QQCOR

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -68.968449
   East_Bounding_Coordinate: -68.879549
   North_Bounding_Coordinate: 44.431989
   South_Bounding_Coordinate: 44.309543
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/5f5f968d82ce3550e3bff24a?name=BelfastBay_SwathPlus_bathymetry_tracklines_browse.jpg (JPG)

   Thumbnail image of bathymetry tracklines collected in Belfast Bay, Maine.

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

   Beginning_Date: 12-Sep-2006

   Ending_Date: 27-Sep-2008

   Currentness_Reference:

   Bathymetry data were collected on the following dates: 20060912-20060917 (Julian day 255-260); 20080924-20080927 (Julian day 261-268).

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 (166)
   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 WGS 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

   BelfastBay_SWATHplus_bathymetry_tracklines

   Bathymetry tracklines for surveys 2006-024-FA and 2008-024-FA. (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.

   JD

   Julian day the line was collected representing the interval of time in days since January 1 of the year of collection. (Source: U.S. Geological Survey) Character set

   Line

   Name of the trackline along which SWATHplus-M data were collected in the format: LineNumberFileNumber (i.e.'L1F1') (Source: U.S. Geological Survey) Character set

   Length_km

   Length of SWATHplus-M data line in kilometers (UTM Zone 19N, WGS 84) calculated using ArcGIS Pro. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0.225
   Maximum:	7.221
   Units:	kilometers
   Resolution:	0.001

   SurveyID

   WHCMSC field activity identifier (e.g. "2006-024-FA" where 2006 is the survey year, 024 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set

   VesselID

   Survey vessel name. (Source: U.S. Geological Survey) Character set

   DeviceID

   Sonar device used to collect bathymetry data. (Source: U.S. Geological Survey) Character set

   Entity_and_Attribute_Overview:

   This shapefile with attributes provide a record of all bathymetric files collected in the Belfast Bay survey area.

   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?
   Please recognize the U.S. Geological Survey (USGS) as the source of this information.
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?

How was the data set created?

1. From what previous works were the data drawn?

   SWATHplus-M echo sounder data (source 1 of 1)

   U.S. Geological Survey, Unpublished Material, raw SWATHplus-M data in .sxr format.

   Type_of_Source_Media: disc
   Source_Contribution:

   SONAR CONFIGURATION: Bathymetry data were collected using a Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M interferometric sonar operating at a frequency of 234 kHz. The sonar transducers were mounted on a rigid pole installed on the bow of the RV Rafael and were deployed at a depth of 0.7m below the water line while collecting data. Typical sonar operating parameters include a transmit power of 9, transmit length of 28 cycles, 20148 samples per channel and a 100-meter range.
   A motion reference unit (TSS Ltd.) Dynamic Motion Sensor (DMS) was mounted directly above the transducers and continuously measured vertical displacement (heave), and attitude (pitch and roll) of the survey vessel during data acquisition. Data were recorded to SWATHplus-M raw format (*.sxr) using Swath Processor software. Sound-velocity profiles were collected approximately every 2 hours during the survey using a hand-casted Applied Microsystems SV Plus sound velocimeter. Real-time Kinematic Global Positioning System (RTK-GPS) navigation was used to determine the horizontal and vertical position (x,y,z) of the GPS antenna with sub-meter accuracy mounted on top of the pole. The RTK-DGPS coordinates were transmitted to the survey vessel from a land-based RTK-DGPS station established by the USGS over National Ocean Service (NOS) monument 5191-A Belfast, Penobscot Bay, Maine

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

   Date: Sep-2008 (process 1 of 6)

   Step 1. PROCESS GPS TIDES
   Note: Processing steps 1-3 described here are the same for both of the surveys that collected bathymetry (2006-024-FA, and 2008-024-FA)the processing date reflects the most recent (2008) date.
   Depths were corrected to Mean Lower Low Water (MLLW) using 1 second RTK-GPS heights of the GPS antenna mounted over the SWATHplus-M sonar head. These heights were extracted from each HYPACK navigation file using the AWK script "doRTK1_by_line_FIX" and smoothed in MATLAB (version 7.20.232 R2006a) using a third order polynomial. The smoothed 1-second heights were averaged to 1-minute heights and formatted for use in CARIS HIPS using the AWK script "DoRTK2" to produce the file "TidesAllCARIS.tid" The contact person for this and all subsequent processing steps below is Brian Andrews. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Brian Andrews

   Geographer

   384 Woods Hole Rd.

   Woods Hole, MA
   

   508-548-8700 x2348 (voice)

   508-457-2310 (FAX)

   bandrews@usgs.gov

   Date: Sep-2008 (process 2 of 6)

   Step 2. CONVERT SXR to SXP.
   Each raw SWATHplus-M bathymetric sonar file (sxr) was converted to a SWATHplus processed file (sxp) using SEA SWATHplus Swath Processor (ver. 3.5.19). During the conversion process, sound velocity profiles were used to minimize potential refraction artifacts from fluctuations in the speed of sound within the water column. Various bathymetric filters were applied to eliminate sounding outliers.

   Date: Sep-2008 (process 3 of 6)

   Step 3. IMPORT SXPS to CARIS HIPS.
   A new CARIS HIPS project (ver. 6.1) was created using the Universal Transverse Mercator (UTM) Zone 19, WGS 84 coordinate system. Each SWATHplus processed file (sxp) was imported to the new CARIS project using the Import/Conversion Wizard. A 5-meter resolution Bathymetric and Statistical Error (BASE) Surface was created from the files for each Julian day. The BASE surface for each day was reviewed for any inconsistencies or data anomalies. Navigation was edited as needed using the navigation editor tool in CARIS. Filters were applied to each line including beam to beam slopes and across track angle. The CARIS refraction editor was used to adjust the speed of sound in some cases to flatten out the depth profiles produced by localized variations in speed of sound through the water column.

   Date: Sep-2015 (process 4 of 6)

   STEP 4: EXPORT TRACKLINES FROM CARIS HIPS TO SHAPEFILE
   Convert CARIS Tracklines to Shapefile: The tracklines in the CARIS project was converted to an ESRI shapefile during a two-step process. First the CARIS tracklines were converted to a CARIS Map using the export tool within HIPS "HIPS to CARIS Map" Input File: All lines in the HIPS Project. The "Export Track Lines" option was checked Output File: "SurveyName"BathTrks.des Second, using CARIS Conversion Utility (ver. 2.1) The CARIS Map (.des) file was converted to an ESRI shapefile. During the conversion the name of the HIPS line file "Line" and "JD" was carried over to the shapefile. Input File: "SurveyName"BathTrks.des Output File: BelfastBay_SWATHplus_bathymetry_tracklines.shp

   Date: Sep-2015 (process 5 of 6)

   STEP 5: ADD ATTRIBUTES
   The following attributes were added to the shapefile using the "add field" feature in ArcGIS Pro (v. 2.6): Length_km, SurveyID, VesselID, DeviceID. Length_km field was populating using the "calculate geometry" context menu using UTM 19, WGS84 coordinate system. SurveyID, VesselID, and DeviceID text fields were populated using the "calculate field" context menu.

   Date: 25-Jan-2021 (process 6 of 6)

   Changed the distribution format name from digital data to shapefile to better represent the data. 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?

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?
   These data were navigated using Real-Time Kinematic Global Positioning System (RTK-GPS) which provides horizontal positional accuracies (x and y) on the decimeter scale. The SWATHplus transducers were mounted on a rigid pole from the bow of the R/V Rafael, approximately 0.5 below waterline. Position data were recorded by Hypack Software (v. 4.3).
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   Although this shapefile records every trackline where bathymetry was collected during the two surveys, not all lines were used to produce the final grid (BelfastBay_SwathPlus_Bathymetry_5m.tif).
5. How consistent are the relationships among the observations, including topology?
   This polyline shapefile records the position of each bathymetric trackline collected during surveys 2006-024-FA and 2008-024-FA.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey-ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   USA

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? This data release includes the shapefile BelfastBay_SWATHplus_bathymetry_tracklines.shp, the browse graphic BelfastBay_SWATHplus_bathymetry_tracklines_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file BelfastBay_SWATHplus_bathymetry_tracklines_meta.xml
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:	Shapefile Size: 5.82
     Network links:	https://www.sciencebase.gov/catalog/item/5f5f968d82ce3550e3bff24a https://www.sciencebase.gov/catalog/file/get/5f5f968d82ce3550e3bff24a https://doi.org/10.5066/P90QQCOR

   • Cost to order the data: none

5. What hardware or software do I need in order to use the data set?
   To utilize these data, the user must have software capable of reading shapefile format, or GIS software capable of utilizing web mapping or feature services.

Who wrote the metadata?

Dates:

Last modified: 19-Mar-2024

Metadata author:

Brian Andrews

U.S. Geological Survey, Northeast Region

Geographer

384 Woods Hole Road

Woods Hole, MA

508-548-8700 ext. 2348 (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 Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)