Geotagged sea-floor images and location of bottom images collected in Long Island Sound, Connecticut and New York, in fall 2017 and spring 2018 by the U.S. Geological Survey, University of Connecticut, and University of New Haven during field activities 2017-056-FA and 2018-018-FA (JPEG images, point shapefile, and CSV file)

Step 1: Collected data.
Two marine geological surveys were conducted in Long Island Sound, Connecticut and New York, in fall 2017 and spring 2018. The R/V Connecticut occupied one of the target sites and the SEABOSS was deployed off the vessel's A-frame on the stern of the ship. The SEABOSS was equipped with a modified Van Veen grab sampler, a Nikon D300 digital still camera with a Photosea strobe, two video cameras (one forward-looking so that a shipboard operator could monitor for proper tow depth and obstacles, and one downward-looking, a Kongsberg Simrad OE1365 in this setup, that overlapped with the field of view of the still camera) with a topside feed, a GoPro HERO4 Black camera recording backup video, and lights to illuminate the sea floor for video and photograph collection. During field activity 2018-018-FA in spring 2018, the strobe stopped working consistently, so an additional light was attached next to the strobe at site 2018-018-089. The Nikon photos were too dark and underexposed without the strobe, so a downward-looking 12-megapixel GoPro HERO4 Black camera set to capture images every 10 seconds was attached to the Nikon housing for sites 2018-018-089 through 2018-018-117. The elements of this particular SEABOSS were held within a stainless-steel frame that measured 1.15 x 1.15 meters. The frame had a stabilizer fin that oriented the system as it drifted over the seabed. Two red lasers were set 20 centimeters apart (both as they are mounted on the SEABOSS frame and as seen in photographs and video on the seabed) for scale measurements. The red laser dots can usually be seen in the sea-floor images and videos depending on the bottom type and distance to the sea floor. A third laser is positioned at an angle so that when it intersects the other lasers, the SEABOSS is at the optimum height (approximately 75 centimeters) off the bottom for a photograph. The winch operator lowered the SEABOSS until the sea floor was observed in the topside live video feed. For those sites that were primarily targeted for a sediment grab, the vessel and SEABOSS then drifted with wind and current for up to a few minutes to ensure a decent image with a clear view of the sea floor was acquired; for those sites that were targeted for both a video transect of the sea floor and a sediment grab, the vessel was navigated along a planned transect for up to an hour. A scientist monitored the real-time bottom video and acquired bottom photographs at points of interest by remotely triggering the Nikon camera shutter. The imaged area is most often within 0.5 to 1.25 meters from left to right. Bottom video was also recorded during the drift from the downward-looking Kongsberg video camera directly to hard drives using an Odyssey7 video recorder. Five sites did not have any usable photographs, usually because the strobe was not working, so still-image frame grabs were captured from the bottom videos for these sites in a subsequent process step. Then, at most sites the winch operator lowered the Van Veen grab sampler until it rested on the sea floor. When the system was raised, the Van Veen grab sampler closed and collected a sample as it was lifted off the sea floor. The sampler was recovered to the deck of the survey vessel where a subsample was taken for grain-size analysis at the sediment laboratory at the USGS Woods Hole Coastal and Marine Science Center. A total of 210 sites were occupied aboard the R/V Connecticut with the SEABOSS: 93 sites were occupied in fall 2017 during field activity 2017-056-FA, and 117 sites were occupied in spring 2018 during field activity 2018-018-FA. Bottom images were collected at all 210 sites.

Step 2: Acquired and processed navigation.
During the surveys, WAAS-enabled GPS navigation from a Garmin GPSMAP 76C receiver was logged through a DataBridge data logger and ArcMap GPS. The GPS was set to receive fixes at a 2-second interval in geographic coordinates (WGS 84). Dates and times were recorded in UTC. Log files were saved for each Julian day in text format. An AWK script (parse_gprmc17056.awk for the fall 2017 log files and parse_gprmc18018.awk for the spring 2018 log files) was used to parse the GPRMC navigation string from the log files for each survey and create ASCII Comma Separated Values (CSV) text files. The output files were merged for each survey and then reformatted using an AWK script (nav_time_reformat.awk), creating a processed navigation CSV text file for each sampling survey.

Step 3: Identified camera time offsets for images.
The original JPEG images do not represent spatial data; however, they were geotagged in a subsequent process step by linking the time the image was taken, which was recorded in the JPEG files' Exchangeable image file format (Exif) metadata tags, to the corresponding time in the navigation files. Before geotagging the images, the Nikon and GoPro camera times, which were both set to UTC, were compared to the GPS time using calibration photos to see if a time offset should be applied to the camera time of the photos. Camera time drift and the precision with which the camera time can be set often result in a time offset. Throughout the surveys, photos of an accurate UTC time (as shown on the video, which had an overlay of the GPS time, or on the Time.is website [https://time.is/], which has a precise time synchronized with an atomic clock) were taken with the Nikon and GoPro cameras so that the camera times could be calibrated to the GPS time during image processing. These calibration photographs indicated that the Nikon camera time was 6 seconds behind the GPS time for the first Julian day of surveying in fall 2017 (Julian day 332), between 1 second behind and 1 second ahead of the GPS time for the remainder of the fall 2017 survey (Julian days 333-337), and 0 to 2 seconds behind the GPS time throughout the spring 2018 survey. The GoPro calibration photographs showed that the GoPro camera time was up to 1 second behind the GPS time on Julian day 133, and 10 to 11 seconds ahead of the GPS time on Julian day 135. GoPro calibration photographs were not available for Julian day 134, so four images from that day were visually compared to the sea-floor video (which was recorded with an overlay of the GPS time) and found to have a camera time 5 to 6 seconds ahead of the GPS time. For the Nikon photos, the time offset from the first Julian day of surveying during fall 2017 (Julian day 332) was corrected in a later process step. The time offsets for the remainder of the Nikon photos were negligible and were not corrected. For the GoPro photos, the time offset from Julian day 133 was negligible and was not corrected. The time offsets for Julian days 134 and 135 were corrected in a later process step.

Step 4: Prepared navigation for geotagging application.
Before geotagging the images, the navigation files were checked for erroneous and missing fixes and then converted to a GPS track log file format supported by ExifTool. To prepare the navigation data, first, a column of the original source filename was deleted from each processed navigation CSV text file (DataBridgeNav_GPRMC_ALL.csv for fall 2017 and 2018018_AllDataBridgeNav_parsed.csv for spring 2018), and the time field was formatted to a fixed-length number with six digits in Microsoft Excel 2016 for Mac, which added leading zeros as necessary. Rows with no coordinates were then deleted, and typos in the time and date were corrected as needed. Next, shapefiles were created from each CSV file in Esri ArcGIS (version 10.3.1) and used to identify erroneous fixes, which were deleted from the CSV text files. The shapefiles were also used to identify gaps in the navigation. For the fall 2017 data, missing navigation was interpolated in Esri ArcGIS to get 2-second navigation for site NB32 where the navigation dropped out for 154 seconds on Julian day 333. To do this, a line segment was created between the last and first known fixes around this gap (between GPS times 22:49:38 and 22:52:12). The Construct Points editing tool was used to create 153 evenly spaced points along the line segment so that a point was created for each second. The coordinates of the points were calculated using the Calculate Geometry tool (Property=X Coordinate of Point and Y Coordinate of Point; Use coordinate system of the data source=WGS 1984; Unit=Decimal Degrees). The interpolated points with even seconds were selected and exported as a CSV file (points with even seconds were extracted so that the navigation was interpolated at a 2-second interval), the coordinates were rounded to seven decimal places in Microsoft Excel 2016 for Mac, and the points were added to the processed navigation CSV text file. For the spring 2018 survey, the navigation was also logged using ArcMap GPS, so shapefiles of the ArcMap GPS logs were used to fill in gaps. Any feature from the ArcMap GPS logs not within 0.1 meters of the original navigation was selected, exported, and added to the navigation CSV file. Concurrent fixes were deleted, and any gaps 6 seconds or larger were filled in using data from the ArcMap GPS logs if available (these points intersect other fixes and were not originally exported). Finally, the CSV text files (now named DataBridgeNav_GPRMC_ALL_for_gpx.csv for fall 2017 and 2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs_for_gpx.csv for spring 2018) were converted to GPX files (DataBridgeNav_GPRMC_ALL.gpx and 2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs.gpx) using GPS Visualizer (http://www.gpsvisualizer.com/convert_input?convert_format=gpx, accessed September 15, 2019, for the fall 2017 data and October 7, 2018, for the spring 2018 data).

Step 5: Geotagged the images.
To geotag the images, the following commands were used with ExifTool (version 10.17) to populate the GPS tags (GPSLatitudeRef, GPSLatitude, GPSLongitudeRef, GPSLongitude, GPSTimeStamp, and GSPDateStamp) in the Exif header of each JPEG image. Since the images were acquired during two surveys and various time offsets were applied, different commands were run using slightly different tags.
Fall 2017 Nikon photos from Julian day 332:
exiftool -api GeoMaxIntSecs=66 -api GeoMaxExtSecs=0 -P -geotag ./DataBridgeNav_GPRMC_ALL.gpx -geosync=+6 '-geotime<${DateTimeOriginal}+00:00' ./photos
Fall 2017 Nikon photos from Julian days 333-337:
exiftool -api GeoMaxIntSecs=66 -api GeoMaxExtSecs=0 -P -geotag ./DataBridgeNav_GPRMC_ALL.gpx '-geotime<${DateTimeOriginal}+00:00' ./photos
Spring 2018 Nikon photos:
exiftool -api GeoMaxIntSecs=10 -api GeoMaxExtSecs=0 -P -geotag ./2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs.gpx '-geotime<${DateTimeOriginal}+00:00' ./photos
Spring 2018 GoPro photos from Julian day 133:
exiftool -api GeoMaxIntSecs=10 -api GeoMaxExtSecs=0 -P -m -geotag ./2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs.gpx '-geotime<${DateTimeOriginal}+00:00' ./photos/LISMaRC_Spring2018_20180513*
Spring 2018 GoPro photos from Julian day 134:
exiftool -api GeoMaxIntSecs=10 -api GeoMaxExtSecs=0 -P -m -geotag ./2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs.gpx -geosync=-5 '-geotime<${DateTimeOriginal}+00:00' ./photos/LISMaRC_Spring2018_20180514*
Spring 2018 GoPro photos from Julian day 135:
exiftool -api GeoMaxIntSecs=10 -api GeoMaxExtSecs=0 -P -m -geotag ./2018018_AllDataBridgeNav_parsed_w_ArcMap_GPS_Logs.gpx -geosync=-10 '-geotime<${DateTimeOriginal}+00:00' ./photos/LISMaRC_Spring2018_20180515*
In the above commands, the "-api GeoMaxIntSecs" option sets the maximum interpolation time for geotagging. For the fall 2017 Nikon photos, the maximum interpolation time was set to 66 seconds since the navigation dropped out for 66 seconds on Julian day 336. The maximum interpolation time was set to 10 seconds for the spring 2018 Nikon and GoPro photos since the GPS was set to receive fixes at a 2-second interval and occasionally several consecutive fixes were missing. The "-api GeoMaxExtSecs" option sets the maximum extrapolation time to 0 seconds for geotagging. The "-P" option preserves the FileModifyDate. The "-m" option was used for the GoPro photos to ignore a warning given by ExifTool when reading or writing a file containing unknown MakerNotes. If this option is not used, the following warnings are issued since ExifTool does not recognize the MakerNotes in the GoPro images: "Warning: [minor] Unrecognized MakerNotes; Warning: [minor] Maker notes could not be parsed." The "-geosync" option is used when the image timestamps are not properly synchronized with the GPS time and is equal to the time offset identified in a previous process step; it is the time difference in seconds that is added to the camera time before determining the image's GPS time and location with a leading "+" or "-" added for positive or negative differences (negative if the camera clock was ahead of the GPS time). Finally, the "-geotime<${DateTimeOriginal}+00:00" argument is added to geotag images for which the camera clock was set to UTC. For more information about the ExifTool commands, see https://exiftool.org/geotag.html and https://exiftool.org/faq.html.

Step 6: Culled the images.
Ten of the fall 2017 Nikon photos had no corresponding navigation data and were removed from the dataset. These photos were taken on deck. The remaining Nikon bottom photographs from both surveys were culled to remove photos collected within the water column, on deck, or without a clear view of the sea floor. The GoPro HERO4 Black camera was set to capture images every 10 seconds during a SEABOSS deployment. GoPro photos that intersected a bottom video trackline were selected to remove photos collected within the water column or on deck. The selected photos were then reviewed to choose representative photos for each site with a clear view of the sea floor for publication. For those sites that were primarily targeted for a sediment grab, one GoPro photo per site was selected; for those sites that were targeted for both a video transect of the sea floor and a sediment grab, a representative photo generally every few minutes was selected for publication for a total of 5 to 15 GoPro photos per video transect.

Step 7: Incorporated survey information into the images' metadata tags.
The following commands were used with ExifTool (version 10.17) to incorporate additional survey information into the appropriate metadata tags of each JPEG image. Since the images were acquired during two surveys, different commands were run for each survey's photos using slightly different tags. Information is duplicated in some tags because various software packages access different tags. Please note that depending on the software used to view the metadata tags, only a subset of these tags may be extracted.
Fall 2017 Nikon photos:
exiftool -P -Artist="Seth D. Ackerman, Dann S. Blackwood" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA" -Caption-Abstract="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Long Island Sound, New York, Connecticut, 2017-056-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2017-056-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-056-FA)." -Caption="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA" *.JPG
Spring 2018 Nikon and GoPro photos:
exiftool -P -Artist="Seth D. Ackerman, Dann S. Blackwood" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA" -Caption-Abstract="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Long Island Sound, New York, Connecticut, 2018-018-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2018-018-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-018-FA)." -Caption="Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA" *.JPG
The following tags were populated in the JPEG image headers using the above ExifTool commands:
Exif tags and the information used to populate these tags:
Artist: Seth D. Ackerman, Dann S. Blackwood
Copyright: Public Domain - please credit U.S. Geological Survey
ImageDescription (fall 2017 Nikon photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
ImageDescription (spring 2018 Nikon and GoPro photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
International Press Telecommunications Council (IPTC) tags and the information used to populate these tags:
Caption-Abstract (fall 2017 Nikon photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
Caption-Abstract (spring 2018 Nikon and GoPro photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
Contact: WHSC_data_contact@usgs.gov
CopyrightNotice: Public Domain - please credit U.S. Geological Survey
Credit: U.S. Geological Survey
Keywords (fall 2017 Nikon photos): Long Island Sound, New York, Connecticut, 2017-056-FA, SEABOSS, sea floor, USGS
Keywords (spring 2018 Nikon and GoPro photos): Long Island Sound, New York, Connecticut, 2018-018-FA, SEABOSS, sea floor, USGS
JPEG tag and the information used to populate this tag:
Comment (fall 2017 Nikon photos): Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2017-056-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-056-FA).
Comment (spring 2018 Nikon and GoPro photos): Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2018-018-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-018-FA).
Extensible Metadata Platform (XMP) tag and the information used to populate this tag:
Caption (fall 2017 Nikon photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
Caption (spring 2018 Nikon and GoPro photos): Photograph of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
To extract the information from the image metadata tags using ExifTool, the following command can be used (tested with ExifTool version 10.17):
exiftool -csv -f -filename -GPSTimeStamp -GPSDateStamp -GPSLatitude -GPSLongitude -n -Artist -Copyright -ImageDescription -Caption-Abstract -Contact -CopyrightNotice -Credit -keywords -comment -Caption *.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." Also note that the argument list may be too long if this command is used in a directory with all of the images. As a workaround, the command may be run separately on the fall 2017 and spring 2018 images by using a wildcard to select the images for each year in the directory (e.g., end the above command with LISMaRC_Fall2017*.JPG > out2017.csv to run it on the fall 2017 images and LISMaRC_Spring2018*.JPG > out2018.csv for the spring 2018 images).

Step 8: Captured frame grabs from the bottom video.
Five sites with no usable photographs were identified (sites SB60_abort, 2018-018-013, 2018-018-051, 2018-018-077, and 2018-018-080). For these sites, one to two still-image frame grabs per site were captured from the bottom video. This was a manual process whereby the video was viewed in VLC media player (version 2.2.6) and one or two clear images of the sea floor throughout the drift were captured.

Step 9: Geotagged the video frame grabs and incorporated survey information into the images' metadata tags.
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. A Python script (MCZM_writeexif_2_readfile.py) was then run that incorporated the matched-up location data, along with additional survey information, into the appropriate metadata tags of each JPEG image. Since the images were acquired during two surveys, the script was run separately for each survey's images using slightly different tags. The Python script uses ExifTool (version 10.17) to write the information to the image metadata tags. Information is duplicated in some tags because various software packages access different tags. Please note that depending on the software used to view the metadata tags, only a subset of these tags may be extracted. The following tags were populated in the JPEG image headers:
GPS tags (these values are unique for each image and based on the matched-up location data):
GPSLatitudeRef GPSLatitude GPSLongitudeRef GPSLongitude GPSTimeStamp GSPDateStamp
Exif tags and the information used to populate these tags:
Artist: Seth D. Ackerman, Dann S. Blackwood
Copyright: Public Domain - please credit U.S. Geological Survey
ImageDescription (fall 2017 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
ImageDescription (spring 2018 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
International Press Telecommunications Council (IPTC) tags and the information used to populate these tags:
Caption-Abstract (fall 2017 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
Caption-Abstract (spring 2018 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
Contact: WHSC_data_contact@usgs.gov
CopyrightNotice: Public Domain - please credit U.S. Geological Survey
Credit: U.S. Geological Survey
Keywords (fall 2017 video frame grabs): Long Island Sound, New York, Connecticut, 2017-056-FA, SEABOSS, sea floor, USGS
Keywords (spring 2018 video frame grabs): Long Island Sound, New York, Connecticut, 2018-018-FA, SEABOSS, sea floor, USGS
JPEG tag and the information used to populate this tag:
Comment (fall 2017 video frame grabs): Video frame grab from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2017-056-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-056-FA).
Comment (spring 2018 video frame grabs): Video frame grab from down-looking camera on the USGS SEABOSS deployed from the R/V Connecticut during survey 2018-018-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-018-FA).
Extensible Metadata Platform (XMP) tag and the information used to populate this tag:
Caption (fall 2017 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2017-056-FA
Caption (spring 2018 video frame grabs): Image of the sea floor in Long Island Sound, New York and Connecticut, from survey 2018-018-FA
To extract the information from the image metadata tags using ExifTool, the following command can be used (tested with ExifTool version 10.17):
exiftool -csv -f -filename -GPSTimeStamp -GPSDateStamp -GPSLatitude -GPSLongitude -n -Artist -Copyright -ImageDescription -Caption-Abstract -Contact -CopyrightNotice -Credit -keywords -comment -Caption *.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." Also note that the argument list may be too long if this command is used in a directory with all of the images from this publication. As a workaround, the command may be run separately on the fall 2017 and spring 2018 images by using a wildcard to select the images for each year in the directory (e.g., end the above command with LISMaRC_Fall2017*.JPG > out2017.csv to run it on the fall 2017 images and LISMaRC_Spring2018*.JPG > out2018.csv for the spring 2018 images). This process step and all subsequent process steps were performed by the same person, Emily Huntley.

Step 10: Renamed the images.
The images were renamed to include LISMaRC (which stands for Long Island Sound Mapping and Research Collaborative), season, year, and GPS date and time in the ISO 8601 standard (YYYYMMDD T [time separator] HHMMSS Z [Zulu/UTC time]) in the filename. The fall 2017 Nikon and spring 2018 GoPro photo filenames end in the original filename, and the video frame grabs end in "OdysseyFrameGrab." Renaming the images was done by creating a shell script with the original image name and the new filename with the GPS date and time information parsed from the image's Exif metadata tags.

Step 11: Created a CSV file of the bottom image locations.
The information from the image metadata tags was extracted using the following ExifTool (version 10.17) commands (the argument list was too long when it was run in a directory with all of the images, so a wildcard was used to run the command separately on the fall 2017 and spring 2018 images):
Command for fall 2017 images:
exiftool -csv -f -filename -GPSTimeStamp -DateTimeOriginal -GPSDateStamp -GPSLatitude -GPSLongitude -n -comment LISMaRC_Fall2017*.JPG > out2017.csv
Command for spring 2018 images:
exiftool -csv -f -filename -GPSTimeStamp -DateTimeOriginal -GPSDateStamp -GPSLatitude -GPSLongitude -n -comment LISMaRC_Spring2018*.JPG > out2018.csv
Microsoft Excel 2016 for Mac was used to merge the two output CSV files into one file; rename the field names for the filename (PICNAME), GPS time (GPSTIME), original camera time (CAMR_TIME), GPS date (DATE), latitude (LAT), and longitude (LONG); add new fields for the camera (CAMERA), time offset applied to the camera time (TIMEOFFSET), Julian day of collection (JD), year of collection (YEAR), survey ID (FA_ID), sampling device used to collect the image (DEVICE_ID), and survey vessel (VEHICLE_ID); and remove additional fields extracted from the ExifTool command.

Step 12: Created a final shapefile and CSV file of the bottom image locations.
A shapefile was created from the bottom image locations CSV file in Esri ArcGIS (version 10.3.1). XTools Pro (version 12.0) for Esri ArcGIS was used to modify field parameters (Table Operations - Table Restructure) in the point shapefile. The Spatial Join tool was then run to calculate the site number (FIELD_NO), video trackline (LINENAME), and University of Connecticut's NURTEC site name for the spring 2018 survey (COMMENTS). These attributes were added to each bottom image using the Spatial Join tool by joining the attributes of the bottom video tracklines shapefile using the intersect match option with a search radius of 0.01 meters. Nine images intersected two tracklines, so the site number and video trackline name were edited if needed to match the GPS time of the image to the corresponding bottom video trackline. Forty-two of the bottom images did not intersect a bottom video trackline, so the site number and NURTEC site name, if applicable, were assigned to these images using information from the survey logs. These images were taken during the second deployment with no video or shortly before the video trackline, so a no data value of -9999 was added to the blank video trackline attributes. Unnecessary fields created when running the Spatial Join tool were deleted (i.e., Join_Count and TARGET_FID). Finally, the shapefile's attribute table was exported in Esri ArcGIS and saved as a CSV file. The FID field was deleted in the CSV file.