Town Neck Beach, Massachusetts, 5 cm 2016-2017 Orthomosaics

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Frequently anticipated questions:


What does this data set describe?

Title: Town Neck Beach, Massachusetts, 5 cm 2016-2017 Orthomosaics
Abstract:
Low-altitude (80-100 meters above ground level) Unmanned Aircraft Systems (UAS) imagery of Town Neck Beach in Sandwich, Massachusetts, were used in a structure-from-motion (SfM) photogrammetry workflow to create high-resolution topographic datasets. Imagery was collected at close to low tide on twelve days to observe changes in beach and dune morphology. Ground control points (GCPs), which are temporary targets on the ground located by using a real-time kinematic global navigation satellite system (RTK-GNSS) base station and rover, were used to constrain the SfM process. Photoscan (v. 1.2-1.4) was used to create a digital elevation model and orthomosaic for each data collection day. Collection of these data was supported by the U.S. Geological Survey Coastal/Marine Hazards and Resources Program and were conducted under USGS field activity numbers 2016-013-FA, 2016-043-FA, 2016-053-FA, 2016-054-FA, 2016-055-FA, 2017-005-FA, 2017-008-FA, 2017-010-FA, 2017-014-FA, 2017-027-FA, 2017-029-FA, and 2017-050-FA.
Supplemental_Information:
For more information see the imagery and GCP releases; https://www.sciencebase.gov/catalog/item/5a7daca0e4b00f54eb24a4f5 and https://www.sciencebase.gov/catalog/item/5cf12e89e4b056af3664e718. UAS mapping was conducted at Town Neck Beach and adjacent Spring Hill Beach (January 9, 2017 only) in Sandwich, Massachusetts. The products of the imagery releases include the data collected in 2016 and 2017. The bounding coordinates below represent the maximum extents of all the surveys, no single survey covers the entire extent. Geospatial software is recommended for viewing.
  1. How might this data set be cited?
    U.S. Geological Survey, 20210824, Town Neck Beach, Massachusetts, 5 cm 2016-2017 Orthomosaics: data release DOI:10.5066/P9BFD3YH, 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.

    Sherwood, C., Over, J., and Soenen, K., 2021, Structure from motion products associated with UAS flights in Sandwich, Massachusetts between January 2016 - September 2017: data release DOI:10.5066/P9BFD3YH, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Sherwood, C.R., Over, J.R., and Soenen, K., 2021, Structure from motion products associated with UAS flights in Sandwich, Massachusetts: U.S. Geological Survey data release, https://doi.org/10.5066/P9BFD3YH.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.49789642
    East_Bounding_Coordinate: -70.45183235
    North_Bounding_Coordinate: 41.77683606
    South_Bounding_Coordinate: 41.75434970
  3. What does it look like?
    Ortho_Sandwich_browse.jpg https://www.sciencebase.gov/catalog/file/get/60e74f13d34e2a7685d0c89a?name=Ortho_Sandwich_browse.jpg (JPEG)
    Example section of an orthophoto of Town Neck Beach.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 22-Jan-2016
    Currentness_Reference:
    ground condition: data represent twelve days of collection between January 2016 and September 2017
  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 Raster data set. It contains the following raster data types:
      • Dimensions, type Pixel
    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 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in meters
      The horizontal datum used is NAD83_National_Spatial_Reference_System_2011.
      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 1/298.257222.
  7. How does the data set describe geographic features?
    20160122_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on January 22, 2016. Pixel resolution is 5-cm. Pixel based raster matrix with 3 layers of information for each pixel. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20160125_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on January 25, 2016. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20160211_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on February 11, 2016. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20160330_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on March 30, 2016. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20160921_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on September 21, 2016. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170109_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on February 9, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170125_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on January 25, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170214_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on February 14, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170316_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on March 16, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170428_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on April 28, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170504_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on May 4, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    20170918_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif
    A raster dataset (unsigned 8-bit integer Cloud-Optimized GeoTIFF format) with encoded RGB values of Town Neck Beach in Massachusetts as recorded on September 18, 2017. Pixel resolution is 5-cm. (Source: Producer defined)
    Band_1
    Red wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_2
    Green wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Band_3
    Blue wavelength band (Source: Photoscan)
    Range of values
    Minimum:0
    Maximum:255
    Entity_and_Attribute_Overview:
    There are no text attributes associated with an RGB GeoTIFF image. There are no “no-data” values. The filename for each ortho product is formatted as "date_location_DEM_5cm_UTM19N_NAVD88_cog.tif", where date is the date the images were collected (in YYYYMMDD format), location is SandwichTNB where TNB is Town Neck Beach in Massachusetts, Ortho stands for an orthorectifed product, 10cm indicates the resolution of the grid, UTM19N_NAVD88 denotes the horizontal and vertical reference systems, and cog is Cloud Optimized GeoTIFF.
    Entity_and_Attribute_Detail_Citation: USGS

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?
  3. To whom should users address questions about the data?
    Christopher R Sherwood
    U.S. Geological Survey, Northeast Region
    Research Oceanographer
    Mail Stop 999, 384 Woods Hole Road
    Woods Hole, MA
    US

    508-457-2269 (voice)
    508-457-2310 (FAX)
    csherwood@usgs.gov

Why was the data set created?

May be used as a high-resolution visual dataset of Town Neck Beach for use by the public, researchers, and others to observe ground conditions and change over time.

How was the data set created?

  1. From what previous works were the data drawn?
    Imagery and Ground Control Points from 2016 Flights (source 1 of 2)
    Montgomery, Ellyn T, Sherwood, Christopher R, Traykovski, Peter, Irwin, Barry, Borden, Jonathan, Martini, Marinna M, and Minor, Simon, 2019, Geotagged Low-Altitude Aerial Imagery From Unmanned Aerial System Flights Over Town Neck Beach, in Sandwich, Massachusetts, With Associated Ground Control Points, and Transects Collected by the U.S. Geological Survey on January 22, January 25, February 11, March 30, and September 21, 2016: U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Type_of_Source_Media: disc
    Source_Contribution: Source JPEG imagery and control points for 2016 flights
    Imagery and Ground Control Points from 2017 Flights (source 2 of 2)
    Sherwood, Christopher R, Traykovski, Peter A., Montgomery, Ellyn T, Borden, Jonathan, Brosnahan, Sandra M., Irwin, Barry J., Marsjanik, Eric D, Martini, Marinna A, and Suttles, Steven E, 2019, Geotagged Low-Altitude Aerial Imagery from Unmanned Aerial Systems Flights over Town Neck Beach in Sandwich, Massachusetts, With Associated Ground Control Points, and Transects, Collected on January 9, January 25, February 14, March 16, April 28, May 4, and September 18, 2017: U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Type_of_Source_Media: Digital and/or Hardcopy
    Source_Contribution: Source JPEG imagery and control points for 2017 flights
  2. How were the data generated, processed, and modified?
    Date: Nov-2017 (process 1 of 2)
    The images and ground control points published in the 2016 and 2017 data releases were processed in Photoscan (v. 1.2-1.4) following the general workflow of Over and others (2021). The general steps and deviations for each individual date are provided here. All flights were processed in UTM Zone 19N relative to NAD83(2011) and NAVD88 (m).
    1. Separate camera models and camera groups were created for each flight. Image sets were edited to remove images that were blurry, tilted to include the horizon, showed only water, or were taken before takeoff or after landing.
    2. Imagery (with positions) were aligned to create a point cloud using a 'High' alignment setting, keypoint limit of 80,000, tiepoint limit of 0.
    3. The resultant point cloud was filtered using one iteration of the 'Reconstruction uncertainty' filter at a level of 10, one iteration of the 'Projection accuracy' filter at a level of 3, and two iterations of the 'Reprojection accuracy' filer at a level of 0.3. With each filter iteration points were selected, deleted, and then the camera model optimized to refine the focal length, cx, cy, k1, k2, k3, p1, and p2 camera model coefficients.
    4. Detect Markers Tool was used to auto locate GCP targets, and the locations of targets not found through this procedure (including non-standard in-place targets) were manually located.
    5. A high quality dense point cloud was generated for the chunk with 'aggressive' filtering.
    6. A DEM was built from the dense point cloud with interpolation (inverse distance weighting) enabled.
    7. DEM was exported in NAD83(2011) UTM Zone 19N and NAVD88(meters) with a 10 centimeter cell size.
    8. Orthomosaics were generated using the DEM surface and “mosaic” blending mode and exported with a resolution of 5 centimeters. Person who carried out this activity:
    Christopher R Sherwood
    U.S. Geological Survey, Northeast Region
    Research Oceanographer
    384 Woods Hole Road
    Woods Hole, MA
    US

    508-457-2269 (voice)
    508-457-2310 (FAX)
    csherwood@usgs.gov
    Data sources used in this process:
    • Imagery and Ground Control Points from 2016 Flights
    • Imagery and Ground Control Points from 2017 Flights
    Date: 07-Jul-2021 (process 2 of 2)
    Final orthomosaics were turned into Cloud Optimized GeoTIFF (COG) using gdal_translate with the following command: ‘for %i in (.\*.tif) do gdal_translate %i .\cog\%~ni_cog.tif -co COMPRESS=LZW -co COPY_SRC_OVERVIEWS=YES -co BIGTIFF=YES -co TILED=YES’ (v. 3.1.4 accessed October 20, 2020 https://gdal.org/). Where i was the name of each geoTIFF section. Person who carried out this activity:
    Jin-Si R Over
    U.S. Geological Survey, Northeast Region
    Geographer
    384 Woods Hole Road
    Woods Hole, MA
    US

    508-457-2269 (voice)
    508-457-2310 (FAX)
    jover@usgs.gov
  3. What similar or related data should the user be aware of?
    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: US Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This is a user guide that details the Agisoft Metashape workflow that take imagery and creates 3D products. Photoscan is the precursor program to Metashape but the steps are very similar.

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

  1. How well have the observations been checked?
    The source imagery and positional information and metadata that were used to create these photogrammetrically derived digital elevation models are available here: https://doi.org/10.5066/P9CJOMBM and https://doi.org/10.5066/F7QC02RM. Information on the horizontal accuracies of the source data can be found within the data release metadata. Ground Control Points were used to constrain the products. No color corrections were applied to the ortho products. GeoTIFFs are in full-color.
  2. How accurate are the geographic locations?
    The horizontal positional accuracy for each orthomosaic was evaluated against independent photo-identifiable ground control points (GCPs) measured with survey-grade GPS, each survey has between 19-41 GCPs associated with the survey, which have horizontal accuracies around 1.5 cm. The total horizontal Root Mean Square Error (RMSE) of the DEMs is on average 10 cm.
  3. How accurate are the heights or depths?
    There are no vertical positions associated with this data product.
  4. Where are the gaps in the data? What is missing?
    Repeat UAS surveys were done to map Town Neck Beach and adjacent Spring Hill Beach in Sandwich, MA twelve times between January 2016-September 2017. The final ortho products are interpolated and have not been cropped, therefore they may cover more area than the DEM products available in the larger work citation.
  5. How consistent are the relationships among the observations, including topology?
    All aerial photographs were acquired by with the integrated DJI FC300X camera mounted on a DJI Phantom 3 quadcopter unmanned aerial system (UAS). Images were collected along pre-planned lines with 50 to 60% cross-track overlap and 65-70% along-track overlap. After images were aligned the dense cloud was edited (see processing steps) to remove erroneous points from the surface before constructing the elevation model and orthomosaic. The final product may appear blurry or distorted near the surfzone and edges where imagery overlap occurs over moving parts and buildings.

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. 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. Not 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? This data release includes twelve 5-cm resolution LZW compressed Cloud Optimized GeoTIFFs of Sandwich Town Neck Beach from January 2016 to September 2017. In order from oldest to most recent the files are 20160122_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (1248MB), 20160125_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (686MB), 20160211_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (830MB), 20160330_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (1249MB), 20160921_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (1450MB), 20170109_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (1114MB), 20170125_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (786MB), 20170214_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (764MB), 20170316_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (809MB), 20170428_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (821MB), 20170504_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (1246MB), 20170918_SandwichTNB_Ortho_5cm_UTM19N_NAVD88_cog.tif (734MB).
  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, 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?
  5. What hardware or software do I need in order to use the data set?
    Use of this file requires software capable of opening GeoTIFF files and, if desired, capable of visualizing cloud optimized GeoTIFFs

Who wrote the metadata?

Dates:
Last modified: 24-Aug-2021
Metadata author:
Jin-Si R Over
U.S. Geological Survey, Northeast Region
Geographer
384 Woods Hole Road
Woods Hole, MA
US

508-457-2269 (voice)
508-457-2310 (FAX)
jover@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

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