Coastal Bathymetry Data Collected in June 2018 from Fire Island, New York: Wilderness Breach and Shoreface

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Frequently anticipated questions:

What does this data set describe?

Title:
Coastal Bathymetry Data Collected in June 2018 from Fire Island, New York: Wilderness Breach and Shoreface
Abstract:
Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, conducted a bathymetric survey of Fire Island, New York, June 2?17, 2018. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the wilderness breach and the adjacent shoreface environment. During this study, bathymetry data were collected aboard two personal watercraft (PWC) outfitted with single-beam echosounders, as well as a towed seismic sled with similar instrumentation. Additional elevation data were collected using a backpack- mounted Global Positioning System (GPS) on flood shoals and in shallow channels within the wilderness breach.
Supplemental_Information:
For the single-beam bathymetry and GPS data, the differential positioning was obtained through post-processing the base station data to the rover. This dataset was transformed from the initial WGS84 ITRF00 datum to NAD83 NAVD88, using the GEOID12A model (NOAA NGS VDatum software version 3.9 - http://vdatum.noaa.gov/). Similar surveys have occurred in years prior, please see USGS Data Series 1049, 1034, and 1007 for more information regarding acquisition and processing methods.
  1. How might this data set be cited?
    Stalk, Chelsea A., Miselis, Jennifer L., Reynolds, Billy J., Fredericks, Jake J., DeWitt, Nancy T., Farmer, Andrew S., Nelson, Timothy R., Wilcox, Hunter S., and Lemon, Mitchell K., 20181130, Coastal Bathymetry Data Collected in June 2018 from Fire Island, New York: Wilderness Breach and Shoreface: U.S. Geological Survey Data Release doi:10.5066/F7PC30N8, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -73.234725
    East_Bounding_Coordinate: -72.858102
    North_Bounding_Coordinate: 40.740953
    South_Bounding_Coordinate: 40.601521
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 02-Jun-2018
    Ending_Date: 17-Jun-2018
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
  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 (5,007,561)
    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: -75.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      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 North American Datum 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum 1988
      Altitude_Resolution: 0.01
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    Fire_Island_2018_NAD83_NAVD88_G12A_shoreface_xyz.txt, Fire_Island_2018_NAD83_NAVD88_G12A_shoreface_xyz.shp
    Comma-delimited x,y,z file and Esri shapefile containing location, elevation, and date information collected with personal watercraft and ground based GPS along the Fire Island, NY shoreface. (Source: U.S. Geological Survey)
    NAD83_X
    NAD83 UTM x-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:649342.936
    Maximum:680876.345
    Units:meters
    NAD83_Y
    NAD83 UTM y-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:4496719.171
    Maximum:4511007.541
    Units:meters
    NAVD88_Geoid12A
    z-value (elevation) in NAVD88 Geoid 12A (Source: U.S. Geological Survey)
    Range of values
    Minimum:-19.73
    Maximum:-0.020
    Units:meters
    NAD83_Lat
    NAD83 UTM y-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:40.607498
    Maximum:40.730301
    Units:Decimal Degrees
    NAD83_Long
    NAD83 UTM x-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-73.234398
    Maximum:-72.858597
    Units:Decimal Degrees
    Year
    Calendar Year of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:2018
    Maximum:2018
    Units:meters
    DOY
    Day of Year of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:153
    Maximum:168
    Time
    UTC time of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:12:44:57.44
    Maximum:22:49:38.32
    Hypack Line
    Sub-FAN identifier followed by line number and start of line UTC time. (Source: HYPACK/U.S. Geological Survey) N/A
    Fire_Island_2018_NAD83_NAVD88_G12A_Wilderness_Breach_xyz.txt, Fire_Island_2018_NAD83_NAVD88_G12A_Wilderness_Breach_xyz.shp
    Comma-delimited x,y,z file and Esri shapefile containing location, elevation, and date information collected with personal watercraft and ground based GPS within wilderness breach, Fire Island, NY. (Source: U.S. Geological Survey)
    NAD83_X
    NAD83 UTM x-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:676081.084
    Maximum:678833.070
    Units:meters
    NAD83_Y
    NAD83 UTM y-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:4509175.63
    Maximum:4512091.867
    Units:meters
    NAVD88_Geoid12A
    z-value (elevation) in NAVD88 Geoid 12A (Source: U.S. Geological Survey)
    Range of values
    Minimum:-8.989
    Maximum:0.393
    Units:meters
    NAD83_Lat
    NAD83 UTM y-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:40.714438
    Maximum:40.740552
    Units:Decimal Degrees
    NAD83_Long
    NAD83 UTM x-axis coordinate (Zone 18N) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-72.914702
    Maximum:-72.882542
    Units:Decimal Degrees
    Year
    Calendar Year of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:2018
    Maximum:2018
    Units:Meter
    DOY
    Day of Year of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:164
    Maximum:165
    Time
    UTC Time of data acquisition (Source: U.S. Geological Survey)
    Range of values
    Minimum:14:17:49.54
    Maximum:21:05:12.50
    HypackLine
    Sub-FAN identifier followed by line number and start of line UTC time. (Source: HYPACK/U.S. Geological Survey) N/A

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
    • Jennifer L. Miselis
    • Billy J. Reynolds
    • Jake J. Fredericks
    • Nancy T. DeWitt
    • Andrew S. Farmer
    • Timothy R. Nelson
    • Hunter S. Wilcox
    • Mitchell K. Lemon
  2. Who also contributed to the data set?
    Funding and (or) support for this study was provided by the USGS Coastal and Marine Geology Program. The authors are grateful to Mike Bilecki, and Jordan Raphael with the National Park Service, Fire Island National Seashore, who provided permitting, access, and assistance with field logistics. This document was improved by reviews from Dave Thompson and Arnell Forde of the USGS - St. Petersburg, Florida.
  3. To whom should users address questions about the data?
    Chelsea A. Stalk
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    727-502-8000 (voice)
    cstalk@usgs.gov

Why was the data set created?

To determine continued change to the shoreface morphology and breach evolution at Fire Island, New York, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted a bathymetric survey of Fire Island from June 2 to 17, 2018, during Field activity number (FAN) 2018-322-FA. The objectives of the data collection were to map the morphology of the shoreface and the wilderness breach as part of the USGS Hurricane Sandy Supplemental Project. This dataset, Fire_Island_2018_xyz.zip and all other provided data, consist of single-beam and GPS horizontal position and vertical elevation data collected along the Fire Island shoreface and within the wilderness breach, onboard two personal watercraft (PWC) vessels, one towed seismic sled, and two backpack GPS systems. Additional survey and data details are available from CMGDS at, https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-322-FA.

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: 2018 (process 1 of 9)
    GPS Acquisition: A total of four Geographic Positioning System (GPS) base stations were established throughout the survey area, three of which were located on NPS established benchmarks, and one on a USGS-installed benchmark. Located in the western portion of the survey area, NPS benchmark BBDP75 or REST is established near the town of Robins Rest. NPS established benchmarks BBDX67 (HILL) and BBDX09 (DX09) are located near the western dockage at the Watch Hill NPS station. USGS-established benchmark FIVC, is a P/K nail located on the boardwalk leading to the Fire Island Visitor Center complex on the eastern side of wilderness breach. All base stations were occupied for 24 hours and equipped with Ashtech Proflex GPS receivers recording 12-channel full-carrier-phase positioning signals (L1/L2) from satellites via Thales Choke-ring antennas, recording at a rate of 0.1 seconds (s). Person who carried out this activity:
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Billy J. Reynolds
    Engineering Technician
    600 4th St. S
    St. Petersburg, FL
    USA

    727-502-8067 (voice)
    727-502-8181 (FAX)
    breynolds@usgs.gov
    Date: 2018 (process 2 of 9)
    Single-Beam Bathymetry Acquisition: The single-beam bathymetric data were collected under the USGS Field Activity Number (FAN) 2018-322-FA, which encompass data from three separate survey platforms; The RV Shark (18CCT02), a 12-ft Yamaha PWC collected 325.25 line-km (156 lines),the RV Chum (18CCT03), an additional 12-ft Yamaha PWC collected 347.47 line-km (162 lines), and a seismic sled towed by the RV Sallenger (sled FAN 18CCT04) collected 288.44 line-km (98 lines). Boat motion was recorded at 50-millisecond (ms) intervals using a SBG Ellipse A #1 motion sensor aboard each PWC and the sled. HYPACK (version 18.1.8.0), a marine surveying, positioning, and navigation software package, managed the planned-transect information and provided real-time navigation, steering, correction, data quality, and instrumentation-status information to the boat operator. Depth soundings were recorded at 50-ms intervals using an Odom echotrac CV100 sounder with a 200-kilohertz (kHz) transducer on all vessels. Data from the GPS receiver, motion sensor, and fathometer were recorded in real-time aboard all vessels independently and merged into a single raw data file (*.RAW) in HYPACK, with each device string referenced by a device identification code and time stamped to Coordinated Universal Time (UTC). Sound velocity profile (SVP) measurements were collected using three SonTek Castaway Conductivity, Temperature, and Depth (CTD) instruments. The instruments were periodically cast overboard to observe changes in water column speed of sound (SOS). A total of 193 successful sound velocity casts were taken throughout the survey at an average depth of 8.14 meters, and on average produced a sound velocity of 1502.47 meters per second (m/s). Person who carried out this activity:
    Chelsea A. Stalk
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Date: 2018 (process 3 of 9)
    Ground Based Kinematic GPS Acquisition: Elevation data were collected from shallow flood shoals and channels, using two SECO GPS backpacks containing Ashtech Z-Xtreme receivers with Ashtech Marine antennas attached to a pole extending above the head of the surveyors (sub-FAN 18CCT05, BCK1 and BCK2). Positions were recorded at 10 Hz. The elevation of the antenna relative to the ground was the average measurement of the surveyor?s standing and stride height, measuring 1.868 m for Backpack 1 and 1.740 m for Backpack 2. The surveyors did not follow a pre-defined path but collected data over as much of the subaerial and shallow shoals as possible, during low tide. Person who carried out this activity:
    Chelsea A. Stalk
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Date: 2018 (process 4 of 9)
    Differentially Corrected Navigation Processing: The coordinate values of the GPS base stations are the time-weighted average of values obtained from NGS? OPUS. The base station coordinates were imported into GrafNav version 8.7 (Waypoint Product Group) and the kinematic GPS data from the survey vessel or backpack apparatus were post- processed to the concurrent GPS session data at the base stations. During processing, steps were taken to ensure that the trajectories between the base and the rover were clean, resulting in fixed positions. By analyzing the graphs, trajectory maps, and processing logs that GrafNav produces for each GPS session, GPS data from satellites flagged by the program as having poor health or satellite time segments that had cycle slips could be excluded, or the satellite elevation mask angle could be adjusted to improve the position solutions. The final differentially corrected, precise DGPS positions were computed at 0.1 s and exported in ASCII text format. Concurrent post-processed navigation data to single-beam data points replace the uncorrected rover positions, recorded during acquisition, in subsequent processing steps. The GPS data were processed and exported in the WGS84 G1150 (ITRF00) geodetic datum. Person who carried out this activity:
    Chelsea A. Stalk
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Date: 2018 (process 5 of 9)
    All data were processed using CARIS HIPS and SIPS (Hydrographic Information Processing System and Sonar Information Processing System) version 10.4.6. The raw HYPACK data files were imported into CARIS, the differentially corrected navigation files were imported using the generic data parser tool, and any SVP profile casts were entered and edited using the SVP editor. The bathymetric data components (position, motion, depth, and SOS) were then merged and geometrically corrected in CARIS to produce processed x,y,z data. Next, the data were edited for outliers and then further reviewed in the Subset Editor utility for crossing status, and questionable data points or areas. The geometrically corrected point data were then exported as an x,y,z ASCII text file referenced to WGS84(G1150), equivalent to ITRF00, ellipsoid height in meters. Person who carried out this activity:
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Chelsea A. Stalk
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Date: 2018 (process 6 of 9)
    Quality Control, Quality Assurance (QA/QC) and Uncertainty Analysis: All single-beam data exported from CARIS, and elevation data exported from GrafNav were imported into Esri ArcMap version 10.6.0, where a shapefile of the individual sounding data points (x,y,z) was created and plotted in 0.25-m color coded intervals. First, all data were visually scanned for any obvious outliers or problems. Erroneous, ground-based horizontal and vertical positions, such as those that occurred when the surveyor took off the backpack and was transported between shoals, were removed. Next, a trackline shapefile was produced using X-tools Pro "Make Polylines from Points " function for each survey platform. Utilizing both the x,y,z (point) and trackline (polyline) shapefiles, a Python script evaluated elevation differences at the intersection of crossing tracklines by calculating the elevation difference between points at each intersection using an inverse distance weighting equation with a search radius of 1 m. The RMS error for WVR1 (18CCT02), when crossing a trackline it previously surveyed was 14.6 cm and when WRV2 (18CCT03) crossed a trackline it previously surveyed, the RMS error was 14.2 cm. Data acquired by the sled (18CCT04) has an RMS error of 14.5 cm, and the GPS Backpacks have a 6 cm and 2.9 cm RMS error respectively. Please see the Error Analysis table provided in the supplemental Information section of this data release for other crossing error statistics. Once individual platform statistics were obtained, all data within the wilderness breach were merged and crossing analysis yielded a 11.27 cm RMS error. Additionally, all shoreface data were merged and reported an 18.8 cm RMS error. Since the bias between the platform elevations was on the order of the Odom instrument accuracy (1 cm +/- 0.7 percent depth), no adjustments were made. These merged files were exported from Esri ArcMap as an x,y,z text (.txt) file and made available in the download section of this data release, along with the populated trackline shapefiles. Person who carried out this activity:
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Chelsea A. Stalk
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Data sources used in this process:
    • 18CCT02_SBB_Level_03A_xxx_WGS84_UTM18N.txt 18CCT03_SBB_Level_03A_xxx_WGS84_UTM18N.txt 18CCT04_SBB_Level_03A_xxx_WGS84_UTM18N.txt 18CCT05_165_2018_BCK1_HILL_A.txt 18CCT05_165_2018_BCK2_HILL_A.txt
    Data sources produced in this process:
    • Fire_Island_2018_ITRF00_shoreface_xyz.txt Fire_Island_2018_ITRF00_Wilderness_Breach_xyz.txt Fire_Island_2018_ITRF00_shoreface_xyz.shp Fire_Island_2018_ITRF00_Wilderness_Breach_xyz.shp Fire_Island_2018_Wilderness_Breach_Tracklines.shp Fire_Island_2018_shoreface_Tracklines.shp
    Date: 2018 (process 7 of 9)
    Datum Transformation: NOAA's VDatum v.9.9 was used to transform single-beam and GPS elevation data points (x,y,z data) from their data acquisition datum (WGS84 ITRF00) to the North American Datum of 1983 (NAD83) reference frame and the North American Vertical Datum of 1988 (NAVD88) elevation using the National Geodetic Survey (NGS) geoid model of 2012A (GEOID12A). For conversion from the WGS84 ellipsoid to NAVD88, there is a total of 7.616 cm of uncertainty in the transformation (http://vdatum.noaa.gov/docs/est uncertainties.html). Resultant data files have been made available in the downloads section of this data release. Person who carried out this activity:
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Chelsea A. Stalk
    Researcher III
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cstalk@usgs.gov
    Data sources used in this process:
    • Fire_Island_2018_ITRF00_shoreface_xyz.txt Fire_Island_2018_ITRF00_Wilderness_Breach_xyz.txt Fire_Island_2018_ITRF00_shoreface_xyz.shp Fire_Island_2018_ITRF00_Wilderness_Breach_xyz.shp
    Data sources produced in this process:
    • Fire_Island_2018_NAD83_NAVD88_G12A_shoreface_xyz.txt Fire_Island_2018_NAD83_NAVD88_G12A_Wilderness_Breach_xyz.txt Fire_Island_2018_NAD83_NAVD88_G12A_shoreface_xyz.shp Fire_Island_2018_NAD83_NAVD88_G12A_Wilderness_Breach_xyz.shp
    Date: 2018 (process 8 of 9)
    Create Digital Elevation Model: The transformed wilderness breach and shoreface x,y,z data described in the previous processing step were imported into ArcMap using the "Create Feature Class From XY Table" tool. The dataset was then used to create a triangulated irregular network (TIN) using the "Create TIN" tool. The TIN was subsequently converted into a raster file using the "TIN to Raster" tool with a cell size of 100 meters for the shoreface and 25 m for the wilderness breach. The rasters were then exported as an ASCII file using the "ASCII to Raster" tool. In order to ensure no data cells were populated without sufficient data, the Raster ASCII file was imported into Matlab (2015b) and any interpolated grid cells that were more than two cell sizes (50 m or 200 m) away from a data point were set to Not a Number (NaN). The raster data were then exported as an ArcGIS ASCII file from Matlab (2015b) and imported into ArcMap using the "ASCII to Raster" tool. The created grid was then exported from ArcMap as a 32-bit floating GeoTiff, utilizing the Natural Neighbor algorithm. A bounding box was generated for each DEM using Global Mapper version 19.0.2 ?export BBOX/COVERAGES tool. The created feature was then exported as a shapefile and included with the data downloads. When each DEM was compared to the associated x,y,z data, the shoreface DEM yielded a 0.383 m RMS error and the wilderness breach yielded a 0.244 RMS error. Person who carried out this activity:
    Geological Survey St. Petersburg Coastal and Marine Science Center Geological Survey
    Attn: Timothy R. Nelson
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    trnelson@usgs.gov
    Data sources used in this process:
    • Fire_Island_2018_NAD83_NAVD88_G12A_shoreface_xyz.txt Fire_Island_2018_NAD83_NAVD88_G12A_Wilderness_Breach_xyz.txt
    Data sources produced in this process:
    • Fire_Island_2018_NAVD88_G12A_25m_shoreface_DEM.tif Fire_Island_2018_NAVD88_G12A_25m_Wilderness_Breach_DEM.tif
    Date: 13-Oct-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?
    Nelson, Timothy R., Miselis, Jennifer L., Hapke, Cheryl J., Brenner, Owen T., Henderson, Rachel E., Reynolds, Billy J., and Wilson, Kathleen E., 20170512, Coastal Bathymetry Data Collected in May 2015 from Fire Island, New York: Wilderness Breach and Shoreface: U.S. Geological Survey Data Series DS 1049, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

    Nelson, Timothy R., Miselis, Jennifer L., Hapke, Cheryl J., Brenner, Owen T., Henderson, Rachel E., Reynolds, Billy J., and Wilson, Kathleen E., 20170324, Bathymetry Data Collected in October 2014 From Fire Island, New York: The Wilderness Breach, Shoreface, and Bay: U.S. Geological Survey Data Series DS 1034, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

    Nelson, Timothy R., Miselis, Jennifer L., Hapke, Cheryl J., Wilson, Kathleen E., Henderson, Rachel E., Brenner, Owen T., Reynolds, Billy J., and Hansen, Mark E., 20160802, Coastal Bathymetry Data Collected in June 2014 from Fire Island, New York: The Wilderness Breach and Shoreface: U.S. Geological Survey Data Series DS 1007, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

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

  1. How well have the observations been checked?
    The accuracy of the data is determined during data collection. This dataset is derived from a single field survey using identical equipment, set-ups, and staff; therefore, the dataset is internally consistent. Methods are employed to maintain data collection consistency aboard the platforms. 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 then digitally entered into their respective programs. Offsets between the single-beam transducers, motion reference units, and the Ashtech antenna reference point (ARP) were measured and accounted for in post-processing. Differential Global Positioning System (DGPS) coordinates were obtained using post-processing software packages (NGS OPUS, and Waypoint Product Group GrafNav, version 8.7).
  2. How accurate are the geographic locations?
    All static base station sessions were processed through the Online Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The OPUS solutions were entered into a spreadsheet to compute a final, time-weighted position (latitude, longitude, and ellipsoid height) for each base station. The time-weighted positions for all base stations occupying established NPS benchmarks (BBDX67, BBDX09, and BBDP75) were compared against the provided NPS coordinates. The time-weighted positions at base station BBDP75 were within 3 standard deviations of the provided positions (+/-0.4 centimeters [cm] North, +/-0.3 cm East), and the NPS established positions for that base stations were used in subsequent processing steps. The time-weighted positions at base stations BBDX67 and BBDX09; however, varied by more than three standard deviations from the NGS established coordinates. At these base stations, the time-weighted average coordinates computed from the survey occupations were used. The horizontal variability of the base station coordinates at BBDX67 and BBDX09 as well as UGSG-installed mark FIVC, were determined by calculating the maximum difference of any individual occupation from the time-weighted average latitude and longitude values (BBDX67: 0.00005 seconds latitude, 0.00007 seconds longitude; BBDX09: 0.00003 seconds latitude, 0.00006 seconds longitude; and FIVC: 0.00009 seconds latitude, 0.00014 seconds longitude).
  3. How accurate are the heights or depths?
    All static base station sessions were processed through OPUS, which is maintained by NOAA and the NGS. The OPUS solutions were entered into a spreadsheet to compute a final, time-weighted position (latitude, longitude, and ellipsoid height) for each base station. The time-weighted positions for all base stations occupying established NPS marks (BBDX67, BBDX09, and BBDP75) were compared against the provided NPS coordinates. The time-weighted positions at base station BBDP75 was within three standard deviations of the NPS established positions for the mark (+/-0.8 cm), and the provided position for that base station was used in subsequent processing steps. The time-weighted positions at base stations BBDX67 and BBDX09; however, varied by more than three standard deviations from the NGS established coordinates. At these base stations, the time-weighted average coordinates computed from the survey occupations were used. The vertical variability of the base station coordinates at BBDX67 and BBDX09 as well as UGSG-installed mark FIVC, were determined by calculating the maximum difference of any individual occupation from the time-weighted average ellipsoid height values (BBDX67: +/- 0.39 cm; BBDX09: +/- 0.15 cm; FIVC: +/-0.48 cm). The kinematic (rover) trajectories were processed using GrafNav version 8.70 software by Novatel, Inc. Occurrences where a personal watercraft, seismic sled, or kinematic GPS apparatus trackline crosses itself were evaluated to determine vertical uncertainty. The calculated RMS uncertainty for the PWC's are 0.146 meters (m) (18CCT02) and 0.142 m (18CCT03); sled (18CCT04) is 0.145 m and both back packs (18CCT05, Backpack 1 [BCK1] and Backpack 2 [BCK2]) are 0.060 m and 0.029 m, respectively. Please see the associated table in the supplemental information portion of this data release for these values.
  4. Where are the gaps in the data? What is missing?
    This data release contains horizontal position and vertical elevation x,y,z single-beam data from June 2018 collected within the wilderness breach and shoreface of Fire Island, NY. Users are advised to read the complete metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    These datasets are from one field activity with consistent instrument calibrations.

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. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research. These data should not be used for navigational purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    Chelsea A. Stalk
    Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Researcher III
    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? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    This digital publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Last Reviewed: 28-Nov-2018
Metadata author:
Chelsea A. Stalk
Cherokee Nation Technologies/U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Researcher III
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)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/Fire_Island_2018_metadata.faq.html>
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