Bathymetry grid and GPS data from Yellowfin UMS operation at Marconi Beach, CACO, Wellfleet, MA on February 26, 2025

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Frequently anticipated questions:

What does this data set describe?

Title:
Bathymetry grid and GPS data from Yellowfin UMS operation at Marconi Beach, CACO, Wellfleet, MA on February 26, 2025
Abstract:
Surveys with Uncrewed Systems (UxS) were used to collect remote sensing data at Marconi Beach on Cape Cod National Seashore, Wellfleet, Massachusetts after the area experienced multiple erosion events after fall storms in 2024 and the loss of National Park Service beach access stairs. The USGS has a stationary camera system (CoastCam) and meteorological station north of the parking lot on the bluff to observe waves and total water levels. UxS were approved to map the coast in view of the CoastCam and where the Park Service stairs were destroyed to help evaluate the conditions of the site and monitor landscape change from storm impacts. The data products will also help validate the CoastCam imagery datasets. Between September 2024 and March 2025, USGS personnel surveyed five times and collected natural (RGB) color images, lidar data, GPS data, and bathymetric data to produce elevation maps and orthomosaics.
Supplemental_Information:
For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/services/activity.php?fan=2025-005-FA. Note that the bounding coordinates are for the entire area mapped and not individual files. Bathymetry can be used with the elevation models in the larger work citation to create a continuous topobathy model.
  1. How might this data set be cited?
    Over, Jin-Si R., and Traykovski, Peter A., 20251126, Bathymetry grid and GPS data from Yellowfin UMS operation at Marconi Beach, CACO, Wellfleet, MA on February 26, 2025: data release DOI:10.5066/P1Z9NCQX, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Over, Jin-Si R., Brosnahan, Sandra M., Cramer, Jennifer M., Sherwood, Chris R., and Traykovski, Peter A., 2025, Topographic and bathymetric data, aerial imagery, and GPS data collected during UxS operations at Marconi Beach, Cape Cod National Seashore, Massachusetts between September 2024 and March 2025: data release DOI:10.5066/P1Z9NCQX, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Over, J.R., Brosnahan, S.M., Cramer, J.M., Sherwood, C.R., and Traykovski, P.A., 2025, Topographic and bathymetric data, aerial imagery, and GPS data collected during UxS operations at Marconi Beach, Cape Cod National Seashore, Massachusetts between September 2024 and March 2025: U.S. Geological Survey data release, https://doi.org/10.5066/P1Z9NCQX.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -69.96389842
    East_Bounding_Coordinate: -69.95076874
    North_Bounding_Coordinate: 41.89920482
    South_Bounding_Coordinate: 41.88996484
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/67f94fc2d4be022c3e84f2a9?name=2025005FA_Marconi_Feb_bathy_browse.png&allowOpen=true (PNG)
    Bathymetry grid colored by elevation at Marconi Beach.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 26-Feb-2025
    Currentness_Reference:
    Ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster and tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 19
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -69.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983 (National Spatial Reference System 2011).
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.001
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    2025005FA_Marconi_Feb_Yellowfin_Bathymetry_1m.tif
    The GeoTIFF is the interpolated grid of the soundings representing the bathymetry of offshore Marconi Beach on February 26th, 2025. (Source: USGS)
    Value
    Seafloor bottom elevation in EPSG:5703 using GEOID 18. No data value is -3.40282E41. (Source: producer defined)
    Range of values
    Minimum:-13.4264
    Maximum:-0.7229
    Units:meters
    2025005FA_Marconi_Feb_Bathymetry_trackline.csv
    Post-processed and heave corrected GPS and echosounder data. (Source: USGS)
    FAN
    USGS Field Activity Number (Source: USGS)
    ValueDefinition
    2025-005-FAYear, USGS ID, and Field Activity
    Date
    Calendar date of collection (Source: USGS)
    ValueDefinition
    20250226YYYYMMDD
    Latitude NAD83[2011]
    Post-processed x-position of Yellowfin GPS relative to NAD83(2011). (Source: USGS)
    Range of values
    Minimum:41.89009137
    Maximum:41.89908163
    Units:decimal degrees
    Longitude NAD83[2011]
    Post-processed y-position of Yellowfin GPS relative to NAD83(2011). (Source: USGS)
    Range of values
    Minimum:-69.96374399
    Maximum:-69.95091815
    Units:decimal degrees
    Easting 19N
    Post-processed x-position of Yellowfin GPS relative to NAD83(2011)/UTM Zone 19N. (Source: USGS)
    Range of values
    Minimum:420071.486
    Maximum:421051.892
    Units:meters
    Northing 19N
    Post-processed y-position of Yellowfin GPS relative to NAD83(2011)/UTM Zone 19N. (Source: USGS)
    Range of values
    Minimum:4638065.941
    Maximum:4638951.214
    Units:meters
    GPS_z
    Post-processed heave corrected Z-coordinate of Yellowfin GPS relative to NAVD88 with GEOID 18 applied. (Source: USGS)
    Range of values
    Minimum:-0.6800
    Maximum:1.9310
    Units:meters
    Echo_z
    The smoothed Cerulean s500 bed detection range, or the distance between the echosounder and the bottom. (Source: producer defined)
    Range of values
    Minimum:-13.8855
    Maximum:-0.8935
    Units:meters
    Seafloor_z
    Elevation in meters of the seafloor in NAVD88, calculated using Seafloor_z = Echo_z + GPS_z - Sonar_waterline_offset. (Source: producer defined)
    Range of values
    Minimum:-13.9839
    Maximum:-0.5076
    Units:meters
    Entity_and_Attribute_Overview:
    GeoTIFF raster has 1079 columns and 1015 rows. There are 180,992 data points in the trackline CSV file.
    Entity_and_Attribute_Detail_Citation: USGS Field Activity 2025-005-FA

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Jin-Si R. Over
    • Peter A. Traykovski
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Jin-Si R. Over
    U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2297 (voice)
    jover@usgs.gov

Why was the data set created?

The bathymetry products were produced to help the Park Service partnership evaluate the conditions of the site and monitor change from the September nor’easter storm impacts in the nearshore and to be able to create a continuous topobathy profile and dataset.

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: 26-Feb-2025 (process 1 of 2)
    The single-beam bathymetry data were collected by launching Yellowfin into the water from the surf zone. Yellowfin is equipped with a Cerulean s500 echosounder and collects singe-beam data and has an EMLID Reach M2 GNSs reciever for positioning data. The boat was controlled near the shore by Peter Traykovski and put on auto-pilot using predetermined tracklines for longer transects offshore. A base station was set-up in the Nauset Lighthouse parking lot to gather GNSS data. Step completed by Peter Traykovski with help from Athina Lange and Mark Carson.
    Date: 11-Mar-2025 (process 2 of 2)
    The raw bathymetry data was processed with the following steps: 1.Parsed the echosounder data (NMEA GPS Puck, Time, and Echosounder range) into MATLAB (v. 2024a) using MATLAB Scripts developed by Peter Traykovski at WHOI - see contact below. 2. Post Processed Kinematic (PPK) GNSS data from Yellowfin was corrected using the base station (Java Triumph-1) data in Emlid Studio (Version 1.9) using the datum NAD83(2011) and then NAVD88 with GEOID 18 applied. A projection for UTM Zone 19N was also specified to get the Easting and Northing information. 3. Refined time alignment to account for any small-time delays between GPS data and echosounder data collection. This is accomplished using the time lagged cross-correlation of echosounder range and PPK GNSS altitude in locations with a relatively flat bottom. The resulting time shift was 18 seconds. The GPS measures vertical fluctuation of the boat due to waves and these fluctuations are also visible in echosounder data. Outliers in the echosounder data were removed using a despiking function. The equation in Step 5 removes the vertical fluctuation due to waves from the echosounder data leaving only true bathymetry if GPS and the echosounder are well synced. The lagged cross-correlation processing ensures they are synced optimally. 4. The PPK GNSS elevation (GPS_z) positions (collected at a higher frequency than the echosounder) were adjusted for the Antenna_Z_offset (0.15 m) and then interpolated to the time of echosounder samples (Echo_z) with the MATLAB function interp1 (linear interpolation). 5. Calculated sea-floor elevation with reference to the NAVD88 datum in meters using the following equation: Seafloor_z = Echo_z + GPS_z – Sonar_waterline_offset. These values data are available in 2025005FA_Marconi_Feb_Bathymetry_trackline.csv. 6. Gridded Seafloor_z values onto 1 m resolution UTM eastings, northings using MATLAB file exchange script regularizedata3d by Jamal (2020), a cubic interpolation with the optimum smoothness coefficient determined by a Monte Carlo optimization procedure for the data regularization. The function Regularizedata3d (Jamal, 2020) entailed removing one cross-shore line of data from the processing and adjusting the smoothness parameter, so the overall surface fit best fits the removed data. The process was then repeated for all the lines of data. The optimized smoothing parameter was used with all the data for the final processing. 7. The MATLAB function 'roipoly' returned the mask as a binary image, which sets pixels inside the region of interest (ROI) to 1 and pixels outside the ROI to 0. The boundary was developed so that there were no extrapolated bathymetry data outside the tracklines. The masks extent was the convex hull of the tracklines positions (x,y) and a bounding z coordinate of 0.3 represented the surface in reference to NAVD88 in meters. 8. Exported gridded 1 m data in NAD83(2011)/UTM Zone 19N in NAVD88 meters as a GeoTIFF: 2025005FA_Marconi_Feb_Yellowfin_Bathymetry_1m.tif. Note that using NAVD88 as the elevation datum, means that the depths are not true depths but the elevation of the seafloor above or below the datum and GEOID.
    Jamal (2020). RegularizeData3D (https://www.mathworks.com/matlabcentral/fileexchange/46223-regularizedata3d), MATLAB Central File Exchange. Retrieved September 23, 2020. Step processed by P. Traykovski. Person who carried out this activity:
    Peter A. Traykovski
    Woods Hole Oceanographic Institution
    Associate Scientist
    WHOI
    Woods Hole, MA

    508-289-2638 (voice)
    ptraykovski@whoi.edu
  3. What similar or related data should the user be aware of?
    Over, Jin-Si R., Sherwood, Chris R., and Traykovski, Peter A., 2024, Topographic, bathymetric, and ground control data collected at Marconi Beach, Wellfleet, Massachusetts in March and April 2024.: data release DOI:10.5066/P99ST3LT, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication includes the topobathy survey data of Marconi Beach from March and April of 2024.
    Francis, Holly, and Traykovski, Peter A., 2021, Development of a highly portable unmanned surface vehicle for surf zone bathymetric surveying: Journal of Coastal Research Volume 37, Issue 5, p. 933-945,, Allen Press, online.

    Online Links:

    Other_Citation_Details:
    The publication describes the theory behind attaching and processing data from a single beam echosounder attached to an uncrewed marine system (UMS), referred to as an autonomous surface vehicle in the publication.

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

  1. How well have the observations been checked?
    GPS: The base station GPS data and GPS on Yellowfin was assessed with post-processing kinematic (PPK) data.
    Bathymetry: No official quality control (QC) test was performed, but all depth values are internally consistent in relation to each other and are comparable to values of published bathymetry in the area (see Over and others, 2024). The product was interpolated therefore small-scale bathymetry features may not be resolved in this dataset. The actual bathymetry may be less accurate between tracklines. Yaw, pitch, and roll, are not taken into account due to the wide beamwidth, for more processing information see Francis and Traykovski (2021).
  2. How accurate are the geographic locations?
    Navigation information was acquired from the GNSS receiver in PPK mode with a multi-band GNSS antenna that has a theoretical horizontal accuracy of 1-5 cm and average reported xy standard deviation (SD) of 6.5 cm.
  3. How accurate are the heights or depths?
    The location information was acquired from the GNSS receiver in PPK mode with a multi-band GNSS antenna with a theoretical horizontal accuracy of 1-5 cm and average reported z SD of 9.4 cm. The navigational accuracies do not represent the accuracy of the derived bathymetric soundings. The vertical accuracy of the raw data in water depths of 10 meters or less, based on industry standard system specifications for 450 and 500 kHz transmit frequencies, is 5-10 cm. Individual point errors (20-30% of points) due to extreme movement of Yellowfin could be as high as 10 cm, but process steps to interpolate and fit the raster remove a large portion of variability.
  4. Where are the gaps in the data? What is missing?
    Collected data were edited for erroneous soundings by removing outlier points identified after plotting data before being incorporated into the final bathymetric grid. NaNs were also removed from the echosounder data, this tends to occur in shallow waters but occasionally there is a slip. In total this accounts for the removal of 10,443 data points for a remaining 180,922 good returns. The CSV of raw PPK and echosounder values have been edited to remove returns at the beginning and end of the survey when the Yellowfin was on land. There is no extrapolation of data beyond the collected bounds.
  5. How consistent are the relationships among the observations, including topology?
    The data represents single beam echo-sounder bathymetry data collected by Peter Traykovski (WHOI). These data are a combination of PPK elevations collected using a Global Navigation Satellite System (GNSS) receiver (EMLID Reach M2) and soundings from a Cerulean s500 single beam echosounder mounted on a self-righting uncrewed marine vessel named Yellowfin. PPK data was corrected to an onshore base station (JAVA Triumph). The GNSS antenna was offset from the echo-sounder by 0.15 m (referred to as Antenna_Z_Offset), and this was taken into account when calculating the GPS elevation values. The sonar was also offset from the water line by 0.10 m (referred to as Sonar_waterline_offset) and was accounted for when calculating the seafloor depth (see Processing Steps).

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints No access constraints. Please see 'Distribution Information' for details.
Use_Constraints These data are marked with a Creative Commons CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Please recognize the U.S. Geological Survey (USGS) as the source of this information. These data are not intended for navigational use.
  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

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? Bathymetric mapping of Marconi Beach includes the depth soundings, GPS location of the boat, and the seafloor elevation values as a CSV and as a grid.
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Not for navigational use.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 26-Nov-2025
Metadata author:
Jin-Si R. Over
U.S. Geological Survey, Northeast Region
Geographer
U.S. Geological Survey
Woods Hole, MA

508-548-8700 x2297 (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.
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P1Z9NCQX/2025-005-FA_Marconi_Feb_metadata.faq.html>
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