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="Marconi Beach, Massachusetts, 2021-022-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 following headings (the first column is the SourceFile with the unique photo names) and information (anything in () is format based and is only provided to give more context) -Credit="U.S. Geological Survey " -Contact="WHSC_data_contact@usgs.gov " -Copyright="Public Domain " -ImageDescription=" https://cmgds.marine.usgs.gov/data/field-activity-data/2021-022-FA/
; Low-altitude aerial photograph of Marconi beach, Wellfleet, Massachusetts from USGS Field Activity 2021-022-FA " - XMP:UsageTerms= "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 "‚ -Attribution="https://doi.org/10.5066/P9KSG1RQ
" -GPSAreaInformation="position post-processed from nearby GPS " -GPSMapDatum="ESPG: 6317 (NAD83), altitude in NAVD88 Geoid12B" -GPSDateStamp="2021:03:17 " -GPSTimeStamp="(HH:MM:SS UTC) " -GPSLatitude="(in decimal degrees) " -GPSLatitudeRef="N " -GPSLongitude="(in decimal degrees)" -GPSLongitudeRef="W " -GPSAltitude=‚" (in NAVD88 m)‚ "-Artist="Peter Traykovski (WHOI)" -OriginalFilename="M#######.JPG (where # combinations are unique) " *.JPG
To read out the photo information to a csv 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
Fewer tags or additional tags may be taken out with this command from those written above.
3. All the JPEG 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 a field survey ID prefix; a flight number and ID that distinguishes among USGS cameras by make, model, and camera number; the image acquisition date and coordinated universal time (UTC) in ISO8601 format, and a suffix with the original image name. For example, image name '2021022FA_f01r02_20200306T165822Z_M1040356.JPG', 2021022FA is the survey ID, f01 is the flight number, r02 is the internal camera ID, 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.