True color aerial imagery collected during uncrewed aircraft systems (UAS) operations: Plum Island Estuary and Parker River NWR (PIEPR), Massachusetts, November 14, 2017 and March 28, 2019

Step 1: Set up equipment.
A Ricoh GR II camera was mounted on a 3DR Solo Quadcopter UAS. The Ricoh GR II acquired JPEG true color images at 14.2 megapixels with image dimensions of 4352 X 3264 pixels in 2017, and at 16.1 megapixels with image dimensions of 4928 X 3264 pixels in 2019. File sizes are generally between 4 and 6 MB on disc for the 2017 images, and 6 and 7 MB for the 2019 images. In 2017, photos were collected with an ISO of 400 or 800, shutter speeds between 1/100 and 1/3200, and an aperture between 3.5 and 4.9. In 2019, photos were collected with an ISO between 125 and 4500, shutter speeds of 1/2000 or 1/2500, and an aperture between 4.0 and 6.3. For flight, the camera was set to record images at 2-second intervals, activated before takeoff and deactivated after landing.
The 3DR Solo Quadcopter UAS includes an onboard mRo GPS (u-blox Neo-M8N / 3DR SOLO Upgrade), which receives signals from GPS and GLONASS satellites in WGS 84 (G1150) and records telemetry information including latitude, longitude, altitude, GPS time, roll, pitch, yaw, course, and flight mode in a telemetry log file (extension tlog), which was downloaded between each flight using file transfer protocol (FTP).

Step 2: Collected images.
The images were collected during field activity 2017-057-FA on November 14, 2017, and field activity 2019-009-FA on March 28, 2019. During each field activity, flights were flown approximately 100 meters above ground level along pre-planned lines and lasted the duration of the UAS battery life (approximately 15 minutes) or until the flight was completed or aborted. Preflight photos of UTC time displayed on a smartphone accurate timepiece were captured with the camera and used to monitor camera clock drift. During a flight, an image was captured every 2 seconds. After a flight, the SD card was removed from the camera, and all files related to the flight were downloaded and organized by flight number.

Step 3: Renamed the images and incorporated survey information into the images' metadata.
A customized Python program written by Seth Ackerman and Emily Sturdivant was run to rename the images and incorporate standard USGS tags and additional survey information into the images using ExifTool by Phil Harvey (version 10.99). All the images were renamed to ensure unique filenames and compliance with the USGS Coastal and Marine Hazards and Resources Program best practices for image naming convention at the time. The naming convention has since changed and the image filenames were subsequently renamed in a process step below.
The customized Python program also incorporated positional data from the UAS telemetry log into the metadata embedded in the header of each image using ExifTool. Before running the Python program, a time consistency check was conducted between the photos and the telemetry logs, and the telemetry logs recorded in Mission Planner software (version 1.3.49) were saved as GPX files. Using the Python program, photos were geotagged by adding positions from the GPX file to the images using ExifTool. ExifTool uses linear interpolation to determine the position of the device at the time recorded in the image. This creates values for the GPSLatitude, GPS LatitudeRef, GPSLongitude, GPSLongitudeRef, GPSAltitude, GPSTimeStamp, and GPSDateStamp tags.
A Python script was also run that incorporated standard USGS tags into the metadata embedded in the header of each image using ExifTool. Images may have different metadata formats embedded in their headers, and the script incorporated survey information into the following four image metadata formats: Exchangeable image file format (Exif), International Press Telecommunications Council (IPTC), Extensible Metadata Platform (XMP), and JPEG. The standard USGS tags at the time have since changed and were subsequently updated in a process step below. The following tags were populated and were not subsequently updated because they are no longer part of the standard USGS tags. Please note that all of the Exif tags originally populated were subsequently updated.
IPTC tags and the information used to populate the tags:
Caption-Abstract (2017 images): Photographs of the Plum Island marsh, Plum Island, Massachusetts, USA from survey 2017-057-FA Caption-Abstract (2019 images): Low-altitude aerial photograph of Plum Island, Massachusetts from survey 2019-009-FA (https://cmgds.marine.usgs.gov/fan_info.php?fa=2019-009-FA). CopyrightNotice: Public Domain. Please credit U.S. Geological Survey Keywords (2017 images): Plum Island, Massachusetts, 2017-057-FA, UAS, aerial imagery, USGS Keywords (2019 images): Plum Island, Massachusetts, 2019-009-FA, UAS, nadir, USGS
XMP tag and the information used to populate the tag:
Caption (2017 images): Photographs of the Plum Island marsh, Plum Island, Massachusetts, USA from survey 2017-057-FA Caption (2019 images): Low-altitude aerial photograph of Plum Island, Massachusetts from survey 2019-009-FA (https://cmgds.marine.usgs.gov/fan_info.php?fa=2019-009-FA).
JPEG tag and the information used to populate the tag:
Comment (2017 images): Photo from down-looking UAS camera during survey 2017-057-FA. Comment (2019 images): Low-altitude aerial photograph of Plum Island, Massachusetts from survey 2019-009-FA (https://cmgds.marine.usgs.gov/fan_info.php?fa=2019-009-FA).

Step 4: Renamed the images.
A command was run to rename the images again to comply with the current USGS Coastal and Marine Hazards and Resources Program best practices for image naming convention. The renamed images have the field activity ID, camera ID, flight ID, and UTC date and time added to the beginning of each original filename. An example renamed filename is 2017057FA_r01f01_20171114T174502Z_P0021159.JPG where 2017057FA refers to the field activity, r01 refers to the camera (Ricoh sensor 1), f01 refers to the flight number, 20171114T174502Z refers to the image date and time in the ISO 8601 standard (YYYYMMDD T [time separator] HHMMSS Z [Zulu/UTC time]), and P0021159 refers to the original filename assigned to the image by the camera.

Step 5: Incorporated survey information into the images' metadata.
The updated standard USGS tags were incorporated into the metadata embedded in the header of each image using several commands. First, the following ExifTool command was run to incorporate standard USGS tags and survey information into the metadata embedded in the headers of the 2017 images. This command also removes the camera orientation tag because motion caused the camera to think that the orientation (portrait vs. landscape) was changed even though it was mounted in a fixed position
exiftool -P "-XMP:PreservedFileName<Filename" -EXIF:Orientation= -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=2017-057-FA; Low-altitude aerial photograph of Plum Island, Massachusetts, from USGS field activity 2017-057-FA" -XMP:AttributionURL="https://doi.org/10.5066/P9PP35F4" -EXIF:GPSAreaInformation="position derived from UAS GPS" -EXIF:GPSMapDatum="EPSG:7660 (WGS 84 [G1150])" -EXIF:Artist="Woods Hole Coastal and Marine Science Center (WHCMSC) Aerial Imaging and Mapping (AIM) Group" -overwrite_original -ext JPG .
Next, the following ExifTool command was run to remove the orientation tag and incorporate standard USGS tags and survey information into the metadata embedded in the headers of the 2019 images:
exiftool -P "-XMP:PreservedFileName<Filename" -EXIF:Orientation= -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=2019-009-FA; Low-altitude aerial photograph of Plum Island, Massachusetts, from USGS field activity 2019-009-FA" -XMP:AttributionURL="https://doi.org/10.5066/P9PP35F4" -EXIF:GPSAreaInformation="position derived from UAS GPS" -EXIF:GPSMapDatum="EPSG:7660 (WGS 84 [G1150])" -EXIF:Artist="Woods Hole Coastal and Marine Science Center (WHCMSC) Aerial Imaging and Mapping (AIM) Group" -overwrite_original -ext JPG .
Finally, the following ExifTool command was run on both the 2017 and 2019 images to duplicate values from Exif and IPTC metadata tags to XMP tags because various software packages read different tags:
exiftool -P "-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 .
The following metadata tags were populated in the image headers using the above ExifTool commands. Please note that only a subset of these tags may be accessed depending on the software used to view the image metadata.
Exif tags and the information used to populate these tags:
Artist: Woods Hole Coastal and Marine Science Center (WHCMSC) Aerial Imaging and Mapping (AIM) Group Copyright: Public Domain GPSAreaInformation: position derived from UAS GPS GPSMapDatum: EPSG:7660 (WGS 84 [G1150]) ImageDescription (2017 images): https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-057-FA; Low-altitude aerial photograph of Plum Island, Massachusetts, from USGS field activity 2017-057-FA ImageDescription (2019 images): https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-009-FA; Low-altitude aerial photograph of Plum Island, Massachusetts, from USGS field activity 2019-009-FA
IPTC tags and the information used to populate these tags:
Contact: WHSC_data_contact@usgs.gov Credit: U.S. Geological Survey
XMP tags and the information used to populate these tags:
AttributionURL: https://doi.org/10.5066/P9PP35F4 Creator: duplicated from Exif Artist CreatorWorkEmail: duplicated from IPTC Contact Credit: duplicated from IPTC Credit DateCreated: duplicated from Exif DateTimeOriginal Description: duplicated from Exif ImageDescription GPSAreaInformation: duplicated from Exif GPSAreaInformation by copying all the Exif GPS tags to the same-named tags in XMP (-XMP-exif:all<GPS:all) GPSDateTime: duplicated using the composite of Exif GPSDateStamp and Exif GPSTimeStamp GPSLatitude: duplicated using the composite of Exif GPSLatitude and Exif GPSLatitudeRef GPSLongitude: duplicated using the composite of Exif GPSLongitude and Exif GPSLongitudeRef GPSMapDatum: duplicated from Exif GPSMapDatum by copying all the Exif GPS tags to the same-named tags in XMP (-XMP-exif:all<GPS:all) Make: duplicated from Exif Make Model: duplicated from Exif Model ModifyDate: duplicated from Exif ModifyDate PreservedFileName: original image file name, which is unique for each image Rights: duplicated from Exif Copyright 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.
To extract the geotagging and survey information (except for 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 -ext tif . > 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."

Step 6: Create image location CSV file.
The image details were downloaded for the entire set of photos on this data release from the CMHRP Imagery Data System, providing the exif_data.csv file. The file was parsed for records that contain navigation data for the Ricoh camera. The columns containing the date, time, latitude, longitude and image filename were kept, the rest of the columns were deleted, resulting in a simplified CSV image location file. The file header line was edited to give each column names as described in the attribute information in this metadata file.