Low-altitude aerial imagery collected from a Helikite at Marconi Beach, Wellfleet, MA on March 22, 2024

These JPEG images were collected with a camera (Ricoh GRII) hung from the Helikite on a GoPro mount so that the camera faced downward and towards the bluff at a roughly 45-degree angle. The Helikite was on a 60 m string and kitesurfing harness; together, the Helikite and gear were walked up and down the beach to achieve overlapping images. It is recommended when using the imagery for photogrammetric purposes to also use the ground control point locations (see 2024-016-FA_Marconi_nav_GCPs.csv).

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. For more information on the EXIF tags here and automatically populated by the camera see https://exiftool.org/TagNames/EXIF.html
1. The positions and elevations of each image (2024-016-FA_Marconi_photoLocations.csv) are from the estimated locations in the Metashape project using the images and AeroPoint V2s (see larger work citation). These positions are copied out of the project after alignment and refinement (see structure from motion metadata in the larger work citation). ExifTools was used to tag each photo with the following tags: Credit, Copyright, UsageTerms, ImageDescription, Artist, GPSAreaInfo, GPSMapDatum, GPSLatitude, GPSLongitude, and GPSAltitude stored in a CSV file with the command:' -exiftool -csv="C:\directory\name\Geotags_EXIF.csv" C:\directory\name\of\photos *.JPG
To read out the photo information to a CSV when in the directory with the photos the command is: exiftool -csv *.JPG > directory/name/allheaders_out.csv
2. All the JPEG images were renamed with Namexif (https://us.digicamsoft.com/softnamexif.html v 2.2 accessed April 2020) 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 '2024016FA_f01r02_20240322T165822Z_image####.jpg', 2024016FA is the survey ID, f01 is the flight number, r02 is the camera make (Ricoh) and ID (02), and 20240322 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 image####.jpg is the original raw photo name appended to the end of the new filename.