Coastal Multibeam Bathymetry and Backscatter Data Collected in May 2021 From Seven Mile Island, New Jersey

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?
   Stalk, Chelsea A., Farmer, Andrew S., Wei, Emily A., and Miselis, Jennifer L., 20221212, Coastal Multibeam Bathymetry and Backscatter Data Collected in May 2021 From Seven Mile Island, New Jersey:.

   This is part of the following larger work.
   Stalk, Chelsea A., Farmer, Andrew S., Wei, Emily A., and Miselis, Jennifer L., 20221212, Coastal Multibeam Bathymetry and Backscatter Data Collected in May 2021 From Seven Mile Island, New Jersey: U.S. Geological Survey data release doi:10.5066/P9M2EQIR, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

   Online Links:

   • https://doi.org/10.5066/P9M2EQIR

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -74.776033
   East_Bounding_Coordinate: -74.684551
   North_Bounding_Coordinate: 39.106315
   South_Bounding_Coordinate: 39.011586
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 19-May-2021

   Ending_Date: 23-May-2021

   Currentness_Reference:

   ground condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: raster 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):
      • Point (20,815,135)
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 18
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -75.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in meters
      The horizontal datum used is World Geodetic System of 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 1/298.257223563.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: World Geodetic System of 1984
      Altitude_Resolution: 0.001
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values
      

7. How does the data set describe geographic features?

   2021_318_7Mile_MBES_1m_WGS84_UTM18N.xyz

   ASCII text (.xyz) file containing the processed 1-m bathymetric grid x,y,z data in the WGS84 [G1762] realization (ellipsoid height). (Source: HYPACK)

   WGS84_UTM18N_X

   WGS84 UTM Zone 18N X-coordinate (easting) of sample point, in meters. (Source: HYPACK)

   Range of values
   Minimum:	519391.000
   Maximum:	527274.000
   Resolution:	0.001

   WGS84_UTM18N_Y

   WGS84 UTM Zone 18N Y-coordinate (northing) of sample point, in meters. (Source: HYPACK)

   Range of values
   Minimum:	4318110.000
   Maximum:	4328598.000
   Resolution:	0.001

   WGS84_Z

   WGS84 (ellipsoid height) of sample point, in meters. (Source: HYPACK)

   Range of values
   Minimum:	-50.912
   Maximum:	-39.073
   Resolution:	0.001

   TPU

   TPU = Total Propagated Uncertainty, in meters. (Source: CARIS)

   Range of values
   Minimum:	0.039
   Maximum:	0.286
   Resolution:	0.001

   2021_318_7Mile_MBES_1m_NAD83_UTM18N_NAVD88_G12B.xyz

   ASCII text (.xyz) file containing the processed 1-m bathymetric grid x,y,z data in NAD83 [2011], NAVD88, which were derived using the GEOID12B model (orthometric height). (Source: HYPACK; VDatum)

   NAD83_UTM18N_X

   NAD83 UTM Zone 18N X-coordinate (easting) of sample point, in meters. (Source: HYPACK; VDatum)

   Range of values
   Minimum:	519391.52961
   Maximum:	527274.52881
   Resolution:	0.00001

   NAD83_UTM18N_Y

   NAD83 UTM Zone 18N Y-coordinate (northing) of sample point, in meters. (Source: HYPACK; VDatum)

   Range of values
   Minimum:	4318108.98423
   Maximum:	4328596.98164
   Resolution:	0.00001

   NAVD88_GEOID12B_Z

   NAVD88 (orthometric height) of sample point, in meters, with respect to GEOID12B. (Source: HYPACK; VDatum)

   Range of values
   Minimum:	-14.33600
   Maximum:	-2.48700
   Resolution:	0.00001

   TPU_WGS84

   Total Propagated Uncertainty, in meters, as reported for WGS84 data. A static uncertainty value of 7.6158 cm is associated with the transformation of this data. (Source: CARIS)

   Range of values
   Minimum:	0.039
   Maximum:	0.286
   Resolution:	0.001

   Entity_and_Attribute_Overview:

   2021_318_7Mile_MBES_1m_Backscatter.tif: Dataset is GeoTIFF included in the download file, 7Mile_2021_MBES_Backscatter.zip, which is acoustic backscatter intensity data in 32-bit floating point GeoTIFF (.tif) format with 22680 columns and 12722 rows. Dataset is projected to the WGS 1984 UTM Zone 18N coordinate system.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Chelsea A. Stalk
   • Andrew S. Farmer
   • Emily A. Wei
   • Jennifer L. Miselis
2. Who also contributed to the data set?
   U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
3. To whom should users address questions about the data?
   Chelsea A. Stalk

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   Electronics Technician (Marine Instrumentation)

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8000 (voice)

   cstalk@usgs.gov

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?

   Date: 23-May-2021 (process 1 of 4)

   Acquisition: An ERS consisting of multibeam bathymetry and acoustic backscatter was conducted using two Teledyne Reson SeaBat T50-P multibeam echosounders, in dual-head configuration. The pair of Mills Cross [configuration] transmit and receive arrays were placed side-by-side within a bracket that oriented them at opposing 30-degree angles (relative to horizontal). The bracket was pole-mounted on the starboard gunnel of the research vessel (R/V) Sallenger, a 26-foot fiberglass vessel. The sonar arrays were oriented athwartships (primary and secondary arrays facing outward and down to port and starboard, respectively) and located approximately 1-m below the waterline when deployed. An Applanix Pos MV Wavemaster II V5 inertially aided navigation system was used for timing, positioning, and attitude. The Inertial Measurement Unit (IMU) was mounted atop the sonar bracket just aft of the pole. Two Trimble GA830 Global Navigation Satellite System (GNSS) antennas were affixed atop the cabin approximately amidships of the vessel, two meters apart, port-starboard. An AML Oceanographic Micro-X sound velocity sensor was used for speed of sound readings at the sonar head. A Sontek CastAway CTD was used for measuring sound velocity profiles. Hydrographic survey acquisition and processing software, HYPACK/HYSWEEP (version 2020) managed data inputs from sensors and produced two files (.RAW and .HSX). Data were collected in WGS84 [G1762] Universal Transverse Mercator (UTM) Zone 18 North (18N) coordinates. Person who carried out this activity:
   

   Chelsea A. Stalk

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727)502-8000 (voice)

   cstalk@usgs.gov

   Date: 2022 (process 2 of 4)

   Processing: Positioning and attitude data were post-processed in Applanix POSPac MMS (POSPac) software version 8.6 Service Pack 3. Raw position files were imported into POSPac and processed with the IN-Fusion PP-RTX processing mode utilizing Trimble CenterPoint RTX technology, creating smoothed best estimate of trajectory (SBET) files and dynamic error files (SMRMSG) for each day of the survey. Bathymetric data were post-processed in CARIS Hydrographic processing software HIPS/SIPS version 11.4.3. HYPACK acquisition files (.HSX) were first imported into CARIS and then post-processed navigation files (SBET and SMRMSG) were imported and applied. Additionally, GPS tide (GPS tidal corrections utilize GPS height information from real time survey observations to obtain an ellipsoid height) was computed and sound velocity profiles were applied. Roll calibration was also performed, as necessary. TPU was calculated from real time values recorded in the HSX and the SMRMSG files. Data were filtered to exclude any points with RESON Quality flags of 0, 1, and 2 (these flags are assigned to individual soundings at the time of acquisition and are a metric of pass/fail in regard to both brightness and collinearity: 0 = fail both, 1 = pass brightness only, 2 = pass collinearity only), as well as soundings that had a TPU greater than stated IHO Special Order standards (IHO, 2008). Refraction artifacts were addressed using the corrections tool within the Subset Editor. Additional editing was also performed in Subset Editor. A 1-m bathymetric CUBE surface was computed and a visual and statistical inspection of the data effecting the surface was performed and edited as needed to serve as quality control (Calder and Wells, 2007). The final surface was exported as an x,y,z ASCII file using the ‘Base Surface to ASCII’ function. Person who carried out this activity:
   

   Chelsea A. Stalk

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727)502-8000 (voice)

   cstalk@usgs.gov

   Data sources produced in this process:

   • 2021_318_7Mile_MBES_1m_WGS84_UTM18N.xyz

   Date: 2022 (process 3 of 4)

   Backscatter Mosaic Creation: Acoustic Intensity Backscatter data (.7k) were loaded in CARIS Hydrographic processing software HIPS/SIPS version 11.3.4 using the SIPS Backscatter tool. The final CUBE bathymetry surface serves as input for geometric corrections and average temperature and salinity data (derived from the Sontek CastAway CTD measurements taken during acquisition) are utilized by the program to calculate local absorption and transmission loss. These inputs, along with the following settings were entered into the tool, and then processing was initiated [Weighted Average = blending, image type = beam average, weighting = swath, and an Angle-Varying gain = 200]. During processing, the tool automatically creates a pattern file (.bbp) which is used to correct for variations in the beam pattern of the system. Upon completion, a 1-m backscatter mosaic with intensity values ranging from 23.2044 to -42.9844 dB (decibels) was created. Three lines were excluded by the program due to computational error, and a noticeable banding effect is apparent, caused by the inability to gain each sonar head independently within the utilized software suite. After visual inspection, the mosaic was exported as a 32-bit float GeoTIFF (.tif) using the ‘surface to GeoTIFF’ function. Person who carried out this activity:
   

   Chelsea A. Stalk

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8000 (voice)

   cstalk@usgs.gov

   Data sources produced in this process:

   • 2021_318_7Mile_MBES_1m_Backscatter.tif

   Date: 2022 (process 4 of 4)

   Datum Transformation: Final x,y,z ASCII data were converted using NOAA's VDatum v.4.4.2 software conversion tool from the WGS84 [G1762] realization to NAD83 [2011] NAVD88, using the GEOID12B model (orthometric height). Person who carried out this activity:
   

   Chelsea A. Stalk

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8000 (voice)

   cstalk@usgs.gov

   Data sources used in this process:

   • 2021_318_7Mile_MBES_1m_WGS84_UTM18N.xyz

   Data sources produced in this process:

   • 2021_318_7Mile_MBES_1m_NAD83_UTM18N_NAVD88_G12B.xyz

3. What similar or related data should the user be aware of?
   Calder, B.R. and Wells, D.E., 20070129, CUBE User's Manual: University of New Hampshire, Center for Coastal and Ocean Mapping, Durham, NH.

   Online Links:

   • https://scholars.unh.edu/ccom/1217

   Other_Citation_Details: pages 1-54
   

   Organization, International Hydrographic, 200802, IHO Standards for Hydrographic Surveys: International Hydrographic Bureau, 4, quai Antoine 1er B.P. 445 - MC 98011 MONACO Cedex Principaute de Monaco.

   Online Links:

   • https://iho.int/uploads/user/pubs/standards/s-44/S-44_5E.pdf

   Other_Citation_Details: pages 1-28
   

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

1. How well have the observations been checked?
   This dataset was from a single research cruise with exact instrumentation and set up and were therefore internally consistent. Methods were employed to maintain data collection consistency aboard the platform. During mobilization, each piece of equipment was isolated to obtain internal and external offset measurements with respect to the survey platform. All the critical measurements were recorded manually and digitally, into their respective programs.
2. How accurate are the geographic locations?
   All data were collected and processed to meet or exceed International Hydrographic Organization (IHO) Special Order standards for positioning and depth (IHO, 2008). Individual Total Propagated Uncertainty (TPU) values associated with each node are available in the x,y,z file.
3. How accurate are the heights or depths?
   All data were collected and processed to meet or exceed IHO Special Order standards for positioning and depth (IHO, 2008). Individual TPU values associated with each node are available in the x,y,z file. Transformed data have an additional reported vertical transformation error of 7.6158 centimeters (cm).
4. Where are the gaps in the data? What is missing?
   These data are the complete, post-processed x,y,z bathymetric and backscatter data points from multibeam data collected nearshore Seven Mile Island, New Jersey, May 2021.
5. How consistent are the relationships among the observations, including topology?
   These files represent the post-processed bathymetric data (x,y,z) and acoustic intensity (.tif) collected during a multibeam bathymetry survey.

How can someone get a copy of the data set?

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

   U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8000 (voice)

   cstalk@usgs.gov
2. What's the catalog number I need to order this data set? 2021_318_7Mile_MBES_1m_WGS84_UTM18N.xyz, 2021_318_7Mile_MBES_1m_NAD83_UTM18N_NAVD88_G12B.xyz, 2021_318_7Mile_MBES_1m_Backscatter.tif
3. What legal disclaimers am I supposed to read?
   Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS shall not be held liable for improper or incorrect use of the data described or contained herein. Any use of trade, firm, or product 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:	Raster data format, GeoTIFF Size: 367
     Network links:	https://coastal.er.usgs.gov/data-release/doi-P9M2EQIR/data/7Mile_2021_MBES_xyz.zip https://coastal.er.usgs.gov/data-release/doi-P9M2EQIR/data/7Mile_2021_MBES_Backscatter.zip

   • Cost to order the data: None

Who wrote the metadata?

Dates:

Last modified: 12-Dec-2022

Metadata author:

Chelsea A. Stalk

U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center

600 4th Street South

St. Petersburg, FL

USA

(727)502-8000 (voice)

cstalk@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)