Step 8: Geotagged the bottom video frame grabs and incorporated survey information into the frame grabs' metadata.
To geolocate the bottom video frame grabs, a CSV file was created with fields for the filename, GPS date, and GPS time. The videos were recorded with an overlay of the GPS date and time, so this information was entered using the date and time shown on each frame grab. The latitude and longitude of each video frame grab were added to the CSV file by matching the frame grab time with a CSV file of the final processed navigation in Microsoft Excel 2016 for Mac. The CSV file was formatted to have the following fields: SourceFile, GPSDateStamp, GPSTimeStamp, GPSLatitude, GPSLatitudeRef, GPSLongitude, and GPSLongitudeRef. To geotag the images, the following command was used with ExifTool (version 11.86) to populate the GPS tags (GPSLatitudeRef, GPSLatitude, GPSLongitudeRef, GPSLongitude, GPSTimeStamp, and GPSDateStamp) in the Exif metadata of each JPEG image:
exiftool -P -csv="video_frame_grabs_geotag.csv" -overwrite_original *.JPG
Additional survey information was then incorporated into the Exif, IPTC, and XMP metadata embedded in the header of each JPEG image using the following ExifTool command:
exiftool -P -m "-XMP:PreservedFileName<Filename" -IPTC:Credit="U.S. Geological Survey" -IPTC:Contact="WHSC_data_contact@usgs.gov" -EXIF:Copyright="Public Domain" -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." -EXIF:ImageDescription="
https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-034-FA; Video frame grab of the sea floor in Cape Cod Bay, Massachusetts, from USGS field activity 2019-034-FA" -XMP:AttributionURL="
https://doi.org/10.5066/P99DR4PN" -EXIF:GPSAreaInformation="position post-processed from nearby GPS" -EXIF:GPSMapDatum="EPSG:4326 (WGS 84)" -EXIF:DateTimeOriginal="0000:00:00 00:00:00" -EXIF:ModifyDate="0000:00:00 00:00:00" -EXIF:Artist="Woods Hole Coastal and Marine Science Center (WHCMSC) Sea Floor Mapping Group (SFMG)" -EXIF:Make="SeaViewer" -EXIF:Model="6000 HD Sea-Drop" -overwrite_original *.JPG
Finally, the following command was run to duplicate metadata from the Exif and IPTC formats to XMP using ExifTool:
exiftool -P -m "-XMP-photoshop:Credit<IPTC:Credit" "-XMP-iptcCore:CreatorWorkEmail<IPTC:Contact" "-XMP-dc:Rights<EXIF:Copyright" "-XMP-dc:Description<EXIF:ImageDescription" "-XMP-exif:all<GPS:all" "-XMP-exif:GPSLatitude<Composite:GPSLatitude" "-XMP-exif:GPSLongitude<Composite:GPSLongitude" "-XMP-exif:GPSDateTime<Composite:GPSDateTime" "-XMP-photoshop:DateCreated<EXIF:DateTimeOriginal" "-XMP-xmp:ModifyDate<EXIF:ModifyDate" "-XMP-dc:Creator<EXIF:Artist" "-XMP-tiff:Make<EXIF:Make" "-XMP-tiff:Model<EXIF:Model" -overwrite_original *.JPG
The same information that was incorporated into the GoPro photos' metadata was populated in the headers of the video frame grabs with the following exceptions for the Exif tags:
DateTimeOriginal: 0000:00:00 00:00:00 [No data]
ImageDescription:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-034-FA; Video frame grab of the sea floor in Cape Cod Bay, Massachusetts, from USGS field activity 2019-034-FA
Make: SeaViewer
Model: 6000 HD Sea-Drop
ModifyDate: 0000:00:00 00:00:00 [No data]
To extract the geotagging and survey information (except for DateTimeOriginal, ModifyDate, and the duplicated tags) from the image metadata using ExifTool, the following command can be used (tested with ExifTool version 11.86):
exiftool -csv -filename -EXIF:GPSTimeStamp -EXIF:GPSDateStamp -GPSLatitude -GPSLongitude -n -IPTC:Credit -IPTC:Contact -EXIF:Copyright -XMP:UsageTerms -EXIF:ImageDescription -XMP:AttributionURL -EXIF:GPSAreaInformation -EXIF:GPSMapDatum -EXIF:Artist -EXIF:Make -EXIF:Model *.JPG > out.csv
The "-csv" option writes the information to a CSV file. The "-n" option formats the latitude and longitude as signed decimal degrees. Please note that the above command was tested on macOS; Windows users may need to use "exiftool.exe" instead of "exiftool."