SfM digital surface model and orthomosaic representing Head of the Meadow Beach, Truro, MA on March 20, 2024

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
SfM digital surface model and orthomosaic representing Head of the Meadow Beach, Truro, MA on March 20, 2024
Abstract:
The data in this release re-map the beach and nearshore environment at Head of the Meadow Beach in Truro, MA and provide updated environmental context for the 2020 CoastCam installation that looks out at the coast shared by beachgoers, shorebirds, seals, and sharks. This is a collaboration with the National Park Service at Cape Cod National Seashore to monitor the region that falls within the field of view of CoastCam CACO-01, which are two video cameras aimed at the beach. In February and March 2024, U.S. Geological Survey and Woods Hole Oceanographic Institution (WHOI) scientists conducted field surveys to collect topographic and bathymetric data. Images of the beach for use in structure-from-motion were taken with a camera (SONY a6000) attached to a helium powered balloon-kite (Helikite). High-precision GPS targets (AeroPoints 2) were used as ground control points. Bathymetry was collected in the nearshore using a single-beam echosounder mounted on a surf capable self-righting electric autonomous surface vehicle. Agisoft Metashape (v. 2.1.0) was used to create a digital surface model and orthomosaic with the collected imagery.
Supplemental_Information:
For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2024-011-FA.
  1. How might this data set be cited?
    Over, Jin-Si R., 20240530, SfM digital surface model and orthomosaic representing Head of the Meadow Beach, Truro, MA on March 20, 2024: data release DOI:10.5066/P1N57AEG, 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., Sherwood, Chris R., and Traykovski, Peter A., 2024, Topographic and bathymetric data, imagery, and ground control data collected at Head of the Meadow Beach, Truro, Massachusetts in February and March 2024: data release DOI:10.5066/P1N57AEG, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Over, J.R., Sherwood, C.R., and Traykovski, P.A., 2024, Topographic and bathymetric data, imagery, and ground control data collected at Head of the Meadow Beach, Truro, Massachusetts in February and March 2024: U.S. Geological Survey data release, https://doi.org/10.5066/P1N57AEG.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.08055568
    East_Bounding_Coordinate: -70.07548744
    North_Bounding_Coordinate: 42.05326708
    South_Bounding_Coordinate: 42.05002321
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/6616ca4bd34e7eb9eb7d698f?name=2024-011-FA_HOM_SfM_browse.jpg&allowOpen=true (JPEG)
    (left)Elevation relative to NAVD88-colored image of topography and (right) true color orthomosaic of the field site.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 20-Mar-2024
    Currentness_Reference:
    ground condition; one day of data collection on March 20, 2024
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster 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 0.001
      Ordinates (y-coordinates) are specified to the nearest 0.001
      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?
    2024-011-FA_HOM_DSM_UTM19N_NAVD88_10cm.tif
    A raster dataset with encoded elevation values of Head of the Meadow Beach in Truro, MA on March 20, 2024. Pixel resolution is 10 cm. (Source: USGS)
    Value
    Surface elevation orthometric height NAVD88 (m) using Geoid 2018 in NAD83(2011) UTM Zone 19N (Source: producer defined)
    ValueDefinition
    -999No data
    Range of values
    Minimum:-1.031
    Maximum:27.540
    Units:meters
    2024-011-FA_HOM_RGBavg_UTM19N_10cm.tif
    Pixel based raster matrix with 3 layers of information for each pixel. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Agisoft Metashape)
    Range of values
    Minimum:17
    Maximum:255
    Band_2
    Green wavelength band (Source: Agisoft Metashape)
    Range of values
    Minimum:18
    Maximum:255
    Band_3
    Blue wavelength band (Source: Agisoft Metashape)
    Range of values
    Minimum:22
    Maximum:255
    Entity_and_Attribute_Overview:
    The filenames are formatted as "2024-011-FA_HOM_product_HCRS_VCRS_resolution.tif", where 2024-011 is the USGS Field activity ID, location is Head of the Meadow (HOM), product is either DSM or RGBavg, the horizontal coordinate reference system (HCRS) is UTM19N, the vertical coordinate reference system (VCRS) is NAVD88, and resolution is 10 cm.
    Entity_and_Attribute_Detail_Citation: USGS Field Activity 2024-011-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
  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, 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?

High-resolution elevation and true-color dataset of Head of the Meadow Beach can be used to observe conditions and change over time and to validate the CoastCam station.

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: Mar-2024 (process 1 of 1)
    DSM was created in Agisoft Metashape v. 2.1.0 using the following general steps (see Over and others, 2021):
    1. Metashape project was created with imagery (located in larger work citation 2024-011-FA_HOM_f1.zip). Photos were aligned at a low accuracy and then GCPs were automatically detected in the point cloud. Nine GCPs (2024-011-FA_HOM_GCPs.csv) were located.
    2. GCP horizontal and vertical accuracy was set to 0.01/0.02 m. The photos were re-aligned with high accuracy (the pixels are not subsampled for increased processing speed) using a keypoint limit of 40,000 and unlimited tie points.
    3. Metashape software refined and optimized, using least squares, the camera positions, GCPs, and lens model using gradual selection and optimization parameters of: Reprojection uncertainty = 20, Projection accuracy = 5, and Reprojection error = 0.3 to minimize the distance between the measured points and the software created points (see Over and others, (2021) for a detailed discussion on these parameters).
    4. A dense point cloud was generated using high-quality (images are not subsampled) and a low frequency filtering algorithm. The dense point cloud was then edited by hand to remove erroneous points before generating a DSM with interpolation disabled.
    5. The DSM was then exported (2024-011-FA_HOM_DSM_UTM19N_NAVD88_10cm) from the software at a resolution of 10 cm in NAD83(2011)/UTM Zone 19N and NAVD88 (m)
    6. A second DSM with interpolation enabled was created and from that surface an orthomosaic using the RGB averaged method was created. The orthomosiac was then exported ((2024-011-FA_HOM_RGBavg_UTM19N_10cm) from the software at a resolution of 10 cm in NAD83(2011)/UTM Zone 19N. Person who carried out this activity:
    Jin-Si R. Over
    U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA

    508-548-8700 x2297 (voice)
    jover@usgs.gov
  3. What similar or related data should the user be aware of?
    Over, Jin-Si R., Sherwood, Chris R., and Traykovski, Peter A., 2023, Topographic and bathymetric data, structure from motion imagery, and ground control data collected at Head of the Meadow Beach, Truro, MA in February and March 2023, U.S. Geological Survey Field Activity 2023-011-FA: data release DOI:10.5066/P9FYVLCD, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication is the survey data of Head of the Meadow Beach from 2023.
    Over, Jin-Si R., Sherwood, Chris R., Traykovski, Peter A., and Marsjanik, Eric, 2022, Topographic and bathymetric data, structure from motion imagery, and ground control data collected at Head of the Meadow Beach, Truro, MA in March 2022, U.S. Geological Survey Field Activity 2022-015-FA: data release DOI:10.5066/P9GEVWG1, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication is the survey data of Head of the Meadow Beach from 2022.
    Over, Jin-Si R., Sherwood, Chris R., and Traykovski, Peter A., 2022, Topographic and bathymetric data, structure from motion imagery, and ground control data collected at Head of the Meadow, Truro in February 2021, U.S Geological Survey Field Activity 2021-014-FA: data release DOI:10.5066/P9D94NZ3, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication is the survey data of Head of the Meadow Beach from 2021.
    Over, Jin-Si R., Sherwood, Chris R., Traykovski, Peter A., Brosnahan, Sandra M., Marsjanik, Eric E., and Borden, John S., 2021, Topographic and bathymetric data, sediment samples, and beach imagery collected at Head of the Meadow, Truro in March 2020, U.S Geological Survey Field Activity 2020-015-FA: data release DOI:10.5066/P9KSG1RQ, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication is the survey data of Head of the Meadow Beach from 2020.
    Over, Jin-Si R., Ritchie, Andrew C., Kranenburg, Christine J., Brown, Jenna A., Buscombe, Daniel D., Noble, Tom, Sherwood, Christopher R., Warrick, Jonathan A., and Wernette, Phillipe A., 2021, Processing coastal imagery with Agisoft Metashape Professional Edition, version 1.6-Structure from motion workflow documentation: Open-File Report 2021-1039, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication includes the general methodology for processing imagery in Metashape to produce digital surface models and ortho products.

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

  1. How well have the observations been checked?
    No color corrections were applied. Ground control point (GCP) error in the Metashape project is used to assess overall error in the product.
  2. How accurate are the geographic locations?
    The GCPs (n=9) have a theoretical accuracy of 1-2 cm. The horizontal RMSE of the GCPs was xy: 0.028, 0.019 (m). The final products were compared to the previous survey at Head of the Meadow (see cross-reference) and the orthos and DSMs align at stable features.
  3. How accurate are the heights or depths?
    The GCPs (n=9) have a theoretical accuracy of 1-2 cm. The vertical RMSE of the GCPs was z: 0.010 (m). The final products were compared to the previous survey at Head of the Meadow (see cross-reference) and orthos and DSMs align at stable features.
  4. Where are the gaps in the data? What is missing?
    The structure-from-motion process that builds the products uses all the available imagery and location information at the start, however data holes may appear due to a lack of overlap. The DSM is also not interpolated between data holes. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    The orthomosaic and digital surface model (DSM) of Head of the Meadow Beach are created from imagery and GCPs in the larger work citation.

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. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
  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? GeoTIFF files are the structure-from-motion products of Head of the Meadow Beach in 2024.
  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. 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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    GIS software capable of reading a GeoTIFF.

Who wrote the metadata?

Dates:
Last modified: 30-May-2024
Metadata author:
Jin-Si R. Over
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
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_P1N57AEG/2024-011-FA_HOM_SfM_meta.faq.html>
Generated by mp version 2.9.51 on Fri Jun 7 15:28:28 2024