Still images in JPEG format of the sediment surface in the grab sampler, collected on Stellwagen Bank during U.S. Geological Survey field activity 2017-030-FA, aboard the R/V Auk, May 18-23, 2017

Still images of sediment sample surfaces were collected using a hand-held Nikon 7100 digital camera with a resolution of 24 megapixels (6000 x 4000 pixels), using a 18-200x zoom lens with an aperture ranging from f3.5 to f5.6. After retrieval of the SEABOSS and placement on its wooden stand, the two doors (right and left) in the top of the Van Veen grab sampler were opened and a photo was taken of the sediment surface in each side of the sampler bucket. The centimeter scale in the image allows measurement of the distance from the top of the grab bucket to the top of the sediment surface and provides a qualitative measure of the volume of sediment collected by the grab, which is 15 cm deep in the deepest part of the sampler. See the cross-references for a description of the SEABOSS system.

Using the 2017-030-FA_station_data_summary.csv, the approximate time and location of each photo was derived. Six stations in the summary file were for plankton tows, so those records were deleted for this process. Any station that did not collect a sediment sample was also deleted. The station location (latitude and longitude), date and time for each station was extracted from the CSV file. This information was reformatted using an awk script (awksampleimages_2017-030-FA) so that the following columns of information were available: image name (based on the station number), julian day, GPS date (in the format YYYYMMDD), GPS time (in the format HH:MM:SS), latitude, and longitude. This information was written to a CSV file - 2017-030-FA_grabimage_locations.csv. This process step and subsequent process steps (unless otherwise noted), were performed by the same person - VeeAnn A. Cross.

A python script (writeexif_2_readfile_7_25_19.py executed with IDLE version 2.7.14) was then run that incorporated the information from 2017-030-FA_grabimage_locations.csv, along with additional information, into the appropriate locations in the EXIF header of each grab image at each station. The PYTHON script uses ExifTool (version 11.54) to write the information to the image headers of the full-resolution images. The following tags were populated in the JPEG image headers. Information is duplicated in some tags. This was done because different software packages access different tags. GPS tags: The values populated are unique for each image and based on the information exported from the photo locations shapefile.

GPSLatitudeRef
GPSLatitude
GPSLongitudeRef
GPSLongitude
GPSTimeStamp
GSPDateStamp

JPEG tags: The tag is listed along with the information used to populate it. comment: Photo of grab sample in sampler from a hand-held Nikon 7100 digital camera aboard the R/V Auk during survey 2017-030-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-030-FA ). EXIF tags: The tag is listed along with the information used to populate it - which is the same for every image.

ImageDescription: Photo of grab sample in sampler from a sample on Stellwagen Bank, MA from survey 2017-030-FA
Artist: Page C. Valentine
Copyright: Public Domain - please credit the U.S. Geological Survey
UserComment: Image part of USGS data release https://doi.org/10.5066/P94GOZ7C

IPTC tags: The tag is listed along with the information used to populate it - which is the same for every image.

Credit: U.S. Geological Survey
Contact: WHSC_data_contact@usgs.gov
Keywords: Stellwagen Bank, Massachusetts, 2017-030-FA, SEABOSS, sea floor, USGS, ground-truth, https://doi.org/10.5066/P94GOZ7C
CopyrightNotice: Public Domain - please credit U.S. Geological Survey
Caption-Abstract: Photo of grab sample in sampler from a sample on Stellwagen Bank, MA from survey 2017-030-FA

XMP tags: The tag is listed along with the information used to populate it - which is the same for every image. Caption: Photo of grab sample in sampler from a sample on Stellwagen Bank, MA from survey 2017-030-FA To extract the information from the image headers using ExifTool, the following command can be used (tested with ExifTool version 11.54): exiftool.exe -csv -f -filename -GPSTimeStamp -GPSLongitude -GPSLatitude -n -Artist -Credit -comment -keywords -Caption -Copyright -CopyrightNotice -Caption-Abstract -ImageDescription -UserComment *.jpg > out.csv The -csv flag writes the information out in a comma-delimited format. The -n option formats the latitude and longitude as signed decimal degrees.

Added keywords section with USGS persistent identifier as theme keyword.