Low-altitude aerial imagery collected from a Helikite at Head of the Meadow Beach, Truro during field activity 2021-014-FA on February 4, 2021

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Frequently anticipated questions:


What does this data set describe?

Title:
Low-altitude aerial imagery collected from a Helikite at Head of the Meadow Beach, Truro during field activity 2021-014-FA on February 4, 2021
Abstract:
These data map the beach and nearshore environment at Head of the Meadow Beach in Truro, MA, providing updated regional context for the 2019 CoastCam installation. CoastCam CACO-01 are two video cameras aimed at the beach that view the coast shared by beachgoers, shorebirds, seals, and sharks. These data were collected as part of field activity 2021-014-FA and a collaboration with the National Park Service at Cape Cod National Seashore to monitor the region. In February 2021, U.S. Geological Survey and Woods Hole Oceanographic Institute (WHOI) scientists conducted field surveys to re-map the field of view of the CoastCam. Aerial images of the beach for use in structure from motion were taken with a camera (Ricoh GRII) and a post-processed kinematic (PPK) system attached to a helium powered balloon-kite (Helikite). High-precision GPS targets (AeroPoints) 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 Small Surf Vehicle (SSV). Agisoft Metashape (v. 1.7.2) was used to create a digital elevation model with the collected imagery and this was merged with the bathymetry in MATLAB (v. 2020) to create a continuous topobathy product.
Supplemental_Information:
Bounding coordinates are based on image positions and may not reflect the full extent of the final product. For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-014-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 20220131, Low-altitude aerial imagery collected from a Helikite at Head of the Meadow Beach, Truro during field activity 2021-014-FA on February 4, 2021: data release DOI:10.5066/P9D94NZ3, 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, J., Sherwood, C., and Traykovski, P., 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:
    Over, J.R., Sherwood, C.R., and Traykovski, P.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: U.S. Geological Survey data release, https://doi.org/10.5066/P9D94NZ3
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.079080
    East_Bounding_Coordinate: -70.074761
    North_Bounding_Coordinate: 42.052749
    South_Bounding_Coordinate: 42.050378
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2021-014-FA/data/Imagery/2021014FA_Truro_imagery_browse.JPG (JPEG)
    Example still image of Head of the Meadow Beach, Truro, MA
    https://cmgds.marine.usgs.gov/data/field-activity-data/2021-014-FA/data/Imagery/2021014FA_Truro_HelikiteCameraAttachment_browse.jpg (JPG)
    Photograph showing how the camera, GNSS, and antenna configuration attaches to the Helikite.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 04-Feb-2021
    Currentness_Reference:
    ground condition; single survey day: aerial imagery was collected on February 4, 2021.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference: embedded in EXIF
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. 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?
    2021014FA_Truro_f1_photolocations.csv contains 222 data records.
    The CSV file contains the post-processed Helikite navigation GNSS data (approximate position of the camera at the moment of each image capture). (Source: USGS)
    ImageName
    File names of individual images, see the Data_Quality_Information and Process_Description for file naming convention. (Source: USGS) Character string.
    UTC_Time
    Time in HH:MM:SS of each corrected camera position in coordinated universal time (UTC). (Source: Processor defined)
    Range of values
    Minimum:15:06:34
    Maximum:15:44:54
    Units:HH:MM:SS
    Latitude
    Post-processed interpolated latitude of kite GNSS antenna position based on time of each image capture, in decimal degrees (NAD83[2011]). (Source: USGS)
    Range of values
    Minimum:42.050378
    Maximum:42.052749
    Units:decimal degrees
    Longtitude
    Post-processed interpolated longitude of kite GNSS antenna position based on time of each image capture, in decimal degrees (NAD83(2011)). Negative values represent W. (Source: USGS)
    Range of values
    Minimum:-70.079080
    Maximum:-70.074761
    Units:decimal degrees
    H_Ell_m
    Post-processed height in meters of kite GNSS antenna position based on time of each image capture using the NAD83(2011) reference ellipsoid. (Source: None)
    Range of values
    Minimum:-7.101
    Maximum:17.013
    Units:meters
    Northing
    Post-processed interpolated X-coordinate of kite GNSS antenna position based on time of each image capture, in NAD83(2011)/UTM Zone 19N. (Source: USGS)
    Range of values
    Minimum:4655929.874
    Maximum:4656195.668
    Units:meters
    Easting
    Post-processed interpolated Y-coordinate of kite GNSS antenna position based on time of each image capture, in NAD83(2011)/UTM Zone 19N. (Source: USGS)
    Range of values
    Minimum:410705.055
    Maximum:411061.460
    Units:meters
    H_Ortho_m
    Post-processed interpolated Z-coordinate of kite GNSS antenna position based on time of each image using NAVD88 correction with Geoid 18. (Source: USGS)
    Range of values
    Minimum:20.483
    Maximum:44.598
    Units:meters
    Entity_and_Attribute_Overview:
    The attributes Latitude, Longitude, H_Ortho_m, and UTC_Time are included in the image headers as GPSLatitude, GPSLongitude, GPSAltitude, and GPSTimeStamp, respectively. A GPSMapDatum header is also included in the images specifying that the latitude and longitude are in NAD83(2011) and altitude is in NAVD88 Geoid12B.
    Entity_and_Attribute_Detail_Citation: USGS Field Activity 2021-014-FA

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?
    Jin-Si Over
    U.S. Geological Survey
    U.S. Geological Survey 384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2269 (voice)
    jover@usgs.gov

Why was the data set created?

Images and positions are used in structure from motion to produce the derivitive elevation model and orthomosaic.

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: 04-Feb-2021 (process 1 of 4)
    These JPG images were collected with a camera (Ricoh GRII HD) labeled 'r##', where 'r' indicates a Ricoh camera, and the following 2 digits normally indicate the camera ID. The camera was wired to the GNSS receiver and duct taped together, then hung from the Helikite (2021014FA_Truro_HelikiteCameraAttachment_browse.JPG) so that the camera faced downward. The Helikite was on a 50 m string and kitesurfing harness; together the Helikite and gear were walked down the beach. The horizontal positions and elevations of each image (2021014FA_Truro_f1_photolocations.csv) were recorded from the GNSS receiver (EMLID Reach M2), which were processed in PPK mode using the MASS CORS network. The navigation data was added to the image EXIF information after the flight as described in the process steps. It is recommended when using the imagery for photogrammetric purposes to also use the Aeropoint locations (see larger work citation Navigation: 2021014FA_Truro_nav_AeroPoints.csv) as ground control points. Person who carried out this activity:
    Peter Traykovski
    Woods Hole Oceanographic Institution
    Associate Scientist
    226 Woods Hole Rd, MS #12
    Woods Hole, MA

    508-289-2638 (voice)
    ptraykovski@whoi.edu
    Date: Feb-2021 (process 2 of 4)
    The GNSS navigation data was processed in Inertial Explorer (https://novatel.com/products/waypoint-software/inertial-explorer, version 8.70.8722). In the software, the data were processed using an 'Antenna Height' of 0.0 m to indicate that there was no offset from the GPS to the camera. The positions were processed in the NAD83(2011) datum, providing the Latitude, Longitude, and H_Ell_m attributes and then Geoid 12B was applied using NAVD88 as the vertical datum and UTM Zone 19N for the horizontal coordinate reference system to produce the Northing, Easting, and H_Ortho_m attributes. All of the attributes here are provided in the 2021014FA_Truro_f1_photolocations.csv but only the latitude, longitude, and H_Ortho_m (NAVD88) were embedded in the image header. Person who carried out this activity:
    Peter Traykovski
    Woods Hole Oceanographic Institution
    Associate Scientist
    226 Woods Hole Rd, MS #12
    Woods Hole, MA

    508-289-2638 (voice)
    ptraykovski@whoi.edu
    Date: 23-Jun-2021 (process 3 of 4)
    The images acquired with the camera were geotagged and processed to add additional information required by the USGS to the EXIF headers using ExifTools (https://exiftool.org/, version: 12.06), and the files were renamed to a unique identifier using Namexif (http://www.digicamsoft.com/softnamexif.html, version 2.1) to avoid any possibility of duplicate names. These steps are described here. 1. Using the GNSS navigation from the previous step, ExifTools was used to geotag each photo with the GPSDateStamp, GPSTimeStamp, GPSLatitude, GPSLongitude, and GPSAltitude stored in a csv file with the command:' -geotag "C:\directory\name\Geotags.csv" -geosync=+23 C:\directory\name\of\photos' where the -geosync command tells the exiftools that the GPS and photo time are offset by 23 seconds. The TimeStamp is in UTC, the latitude and longitude geotags are in NAD83(2011), and the altitude geotag is the H_Ortho_m in NAVD88 (m). The first row of the CSV are the headers; the first column is SourceName (unique image names), and the rest of the columns are the geotags listed in Step 1. Keywords were added with the following command in the directory with all the photographs: exiftool -sep ", " -iptc:keywords="Head of the Meadow Beach, Massachusetts, 2021-014-FA, Ricoh, USGS, aerial imagery" *.JPG 2. Additional EXIF information was added in the directory with all the photos with the command: exiftool -csv=directory\name\EXIF_tags.csv *.JPG Where the CSV file has the attributes below as headings. To read out the photo information to a csv when in the direcotry with the photos the command is: exiftool -csv -f -filename -GPSDateStamp -GPSTimeStamp -GPSLongitude -GPSLatitude -n -Artist -Contact -Comment -Credit -Copyright -ImageDescription -OriginalFileName -AttributionURL -Event -GPSAreaInformation -GPSMapDatum *.JPG > directory/name/out.csv Tags may be added or removed to the command above depending on the information desired.
    3. All the JPG images were renamed with Namexif to ensure unique filenames and compliance with the USGS Coastal and Marine Hazards and Resources Program's best practices for image naming convention. Images were renamed with the field survey ID prefix; flight number, and ID that distinguishes USGS cameras by make/camera number, the image acquisition date, coordinated universal time (UTC) in ISO8601 format, and a suffix with the original image name. For example, image name '2021014FA_f01r02_20200306T165822Z_M1040356.JPG', 2021014FA is the survey ID, f01 is the flight number, r02 is the internal camera ID, and 20200306 is the UTC date in the format YYYYMMDD. A 'T' is used to separate UTC date from UTC time in format HHMMSS followed by a Z, and M1040356.JPG is the original raw photo name appended to the end of the new filename. Because GPS data was collected in UTC and had a 23 second offset from the time produced by the camera (EST), the time in Namexif was shifted +4:00:23. Person who carried out this activity:
    Jin-Si Over
    U.S. Geological Survey
    Geographer
    U.S. Geological Survey
    Woods Hole, MA

    508-548-8700 x2269 (voice)
    jover@usgs.gov
    Date: 11-Apr-2022 (process 4 of 4)
    Update the publication date to 'go live' date. Modified browse graphic name to be the URL to the browse graphic. This work done on 20220307. Add PID to metadata (20220411). Any edits to the metadata also include an update to the metadata date. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Over, Jin-Si R., Sherwood, Chris R., Traykovski, Peter A., Brosnahan, Sandra M., Martini, Marinna A., and Marsjanik, Eric, 2021, Topographic and bathymetric data, sediment samples, and imagery collected at Head of the Meadow Beach, Truro in March 2020, U.S. Geological Survey Field Activity 2020-015-FA: U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This publication is the original/first survey data of Head of the Meadow beach from 2020.

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

  1. How well have the observations been checked?
    The camera (Ricoh GRII HD) used on the kite acquires 16.2 megapixel photos, with file sizes generally between 4 and 6 MB on disc, depending on image complexity. The GPS used on the kite has theoretical vertical and horizontal accuracies of 5 meters.
  2. How accurate are the geographic locations?
    Though the images do not represent spatial data, the spatial information is embedded in the photo and available in the EXIF header of each image, which is derived from the provided Helikite navigation file (2021014FA_Truro_f1_photolocations.csv) in the larger work citation. The location information was acquired from a GNSS receiver (EMLID Reach M2) in PPK mode with a Multi-band GNSS antenna and hot shoe adapter with an estimated horizontal accuracy of 1 cm.
  3. How accurate are the heights or depths?
    Though the images do not represent spatial data, the spatial information is available in the EXIF header of each image, which is derived from the provided Helikite navigation file (2021014FA_Truro_f1_photolocations.csv) in the larger work citation. The location information was acquired from a GNSS receiver (EMLID Reach M2) in PPK mode with a multi-band GNSS antenna and hot shoe adapter with an estimated vertical accuracy of 2 cm.
  4. Where are the gaps in the data? What is missing?
    Photographs were captured every 10 seconds for a total of 289 images, but only 222 are provided; images taken while the Helikite was launched and recovered were removed. All photos included have location information. 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?
    One flight was flown at a target elevation of 40-50 m to map the Head of the Meadow Beach shoreline and bluff face in Truro, MA, on February 4, 2021.

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. 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. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
  1. Who distributes the data set? (Distributor 1 of 1)
    Jin-Si Over
    U.S. Geological Survey
    Geographer
    U.S. Geological Survey
    Woods Hole, MA

    508-548-8700 x2269 (voice)
    jover@usgs.gov
  2. What's the catalog number I need to order this data set? The Windows 10 zip folder 2021014FA_Truro_f1.zip contains 222 JPG images and 2021014FA_Truro_f1_photolocations.csv contains the PPK GNSS navigation data.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data or related materials. 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 these files requires software capable of opening JPG images and, if desired, capable of reading the associated EXIF information. Additionally, the location information is provided in a CSV file for the user to utilize with appropriate software.

Who wrote the metadata?

Dates:
Last modified: 11-Apr-2022
Metadata author:
Jin-Si Over
U.S. Geological Survey
Geographer
U.S. Geological Survey
Woods Hole, MA

508-548-8700 x2269 (voice)
jover@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

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