Geotagged sea-floor photographs and location of bottom photographs collected in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey during field activities 2016-005-FA and 2017-022-FA (JPEG images, point shapefile, and CSV file)

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
Geotagged sea-floor photographs and location of bottom photographs collected in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey during field activities 2016-005-FA and 2017-022-FA (JPEG images, point shapefile, and CSV file)
Abstract:
Two marine geological surveys were conducted in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey (USGS) as part of an agreement with the Massachusetts Office of Coastal Zone Management to map the geology of the sea floor offshore of Massachusetts. Samples of surficial sediment and photographs of the sea floor were collected at 76 sampling sites within the survey area, and sea-floor videos were collected at 75 of the sites. The sediment data and the observations from the photos and videos are used to explore the nature of the sea floor; in conjunction with high-resolution geophysical data, the observations are used to make interpretive maps of sedimentary environments and validate acoustic remote sensing data.
Supplemental_Information:
See the larger work citation to view the sea-floor videos, location of bottom video tracklines, and locations and grain-size analysis results of sediment samples collected during the surveys. For more information about these field activities, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-005-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-022-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 20201116, Geotagged sea-floor photographs and location of bottom photographs collected in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey during field activities 2016-005-FA and 2017-022-FA (JPEG images, point shapefile, and CSV file): data release DOI:10.5066/P9UK5IOF, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Huntley, Emily C., Ackerman, Seth D., Brothers, Laura L., Blackwood, Dann S., Irwin, Barry J., and Pendleton, Elizabeth A., 2020, Sea-floor sediment and imagery data collected in Nantucket Sound, Massachusetts, 2016 and 2017: data release DOI:10.5066/P9UK5IOF, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Huntley, E.C., Ackerman, S.D., Brothers, L.L., Blackwood, D.S., Irwin, B.J., and Pendleton, E.A., 2020, Sea-floor sediment and imagery data collected in Nantucket Sound, Massachusetts, 2016 and 2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9UK5IOF.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.173002
    East_Bounding_Coordinate: -70.037282
    North_Bounding_Coordinate: 41.435695
    South_Bounding_Coordinate: 41.320672
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5f11ed4882ce21d4c409d2dd/?name=2016-005-FA_and_2017-022-FA_photos_browse.jpg (JPEG)
    Map of sea-floor photograph locations in the survey area in Nantucket Sound, Massachusetts.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 02-May-2016
    Ending_Date: 04-May-2017
    Currentness_Reference:
    Data were collected on the following dates: 20160502, 20160503, 20160507, and 20170504
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster, vector, and tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (255)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0000001. Longitudes are given to the nearest 0.0000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    2016-005-FA_and_2017-022-FA_photos
    Bottom photo locations and bottom photos collected during USGS field activities 2016-005-FA and 2017-022-FA in Nantucket Sound, Massachusetts, in 2016 and 2017. (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    PICNAME
    Name of bottom photo used to uniquely identify between surveys, cameras, and photos: e.g., 2016005FA_GoPro4_20160502T134350Z_G0020192.JPG where 2016005FA refers to the field activity, GoPro4 refers to the camera, 20160502T134350Z refers to the photo GPS date and time in the ISO 8601 standard (YYYYMMDD T [time separator] HHMMSS Z [Zulu/UTC time]), and G0020192 refers to the sequential photo number assigned to the photo by the camera. (Source: U.S. Geological Survey) String used to distinguish photos.
    CAMERA
    Camera used to collect bottom photo. (Source: U.S. Geological Survey) String used to distinguish between different camera models mounted on the sampler.
    GPSTIME
    UTC time of bottom photo from GPS navigation file in the format HH:MM:SS. (Source: U.S. Geological Survey) String used to distinguish the UTC times of the bottom photos determined by the GPS.
    CAMR_TIME
    Camera time of bottom photo in UTC in the format HH:MM:SS. (Source: U.S. Geological Survey) String used to distinguish the camera times of the bottom photos determined from the camera's internal clock.
    TIMEOFFSET
    Offset applied, if any, to match the bottom photo to the correct time determined by the GPS navigation. This field is the time difference between the camera time and the GPS time in UTC in the format HH:MM:SS. A value of "00:00:00" indicates no offset was applied in processing. If the camera time were X seconds behind the GPS time, a positive offset of +X would be applied. If the camera were Y seconds ahead of the GPS time, a negative offset of -Y would be applied. (Source: U.S. Geological Survey) String used to distinguish the time offsets of the bottom photos.
    JD
    Julian day that the bottom photo was collected based on UTC time; Julian day is the integer number representing the interval of time in days since January 1 of the year. (Source: U.S. Geological Survey)
    Range of values
    Minimum:123
    Maximum:128
    Units:Julian days
    Resolution:1
    YEAR
    Year that the bottom photo was collected. (Source: U.S. Geological Survey)
    Range of values
    Minimum:2016
    Maximum:2017
    Units:years
    Resolution:1
    DATE
    Date based on UTC time that the bottom photo was collected in the format YYYYMMDD. (Source: U.S. Geological Survey) String used to distinguish dates.
    LAT
    Latitude of bottom photo in geographic coordinates, WGS 84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:41.3206717
    Maximum:41.4356950
    Units:decimal degrees
    Resolution:0.0000001
    LONG
    Longitude of bottom photo in geographic coordinates, WGS 84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.1730025
    Maximum:-70.0372820
    Units:decimal degrees
    Resolution:0.0000001
    FIELD_NO
    Site number as assigned in the field. (Source: U.S. Geological Survey) String used to distinguish site numbers.
    LINENAME
    Name of bottom video used to uniquely identify between surveys, cameras, and video files: e.g., 2016005FA_SeaViewer_20160502T134251Z_CLIP0000045.mp4 where 2016005FA refers to the field activity identifier, SeaViewer refers to the camera, 20160502T134251Z refers to the date and start time in the ISO 8601 standard (YYYYMMDD T [time separator] HHMMSS Z [Zulu/UTC time]), and CLIP0000045 refers to the sequential video number assigned to the video by the camera. (Source: U.S. Geological Survey) String used to distinguish bottom videos.
    FA_ID
    Serial number assigned to the field activity during which the bottom photo was collected. This value is in the format YYYY-XXX-FA where YYYY is the survey year, XXX is the number assigned to the activity within that year, and FA indicates Field Activity. (Source: U.S. Geological Survey) String used to distinguish field activities by year and ID number.
    DEVICE_ID
    Sampling device used to collect the bottom photo. (Source: U.S. Geological Survey) String used to identify the sampling configuration used during the survey.
    VEHICLE_ID
    Vehicle (ship) used to collect data during the field activity. (Source: U.S. Geological Survey) String used to identify the survey vessel.
    Entity_and_Attribute_Overview:
    The CSV file has the same attributes, except for FID (which is not included), with the same definitions.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov

Why was the data set created?

This dataset provides access to the geotagged sea-floor photographs and locations of bottom photographs acquired with a GoPro HERO4 Black camera on the Mini SEABed Observation and Sampling System (MiniSEABOSS) aboard the Research Vessel (R/V) Rafael during USGS field activity 2016-005-FA (May 2 to May 7, 2016) and aboard the R/V Tioga during USGS field activity 2017-022-FA (May 4, 2017). These data were collected to characterize the sea floor by identifying sediment texture and to ground-truth acoustic data collected during USGS field activity 2013-003-FA (Ackerman and others, 2016). Bottom photos serve as a means to visually classify grain size and identify sea-floor habitats, and they are especially important for sample sites where no physical sediment sample was collected.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 04-May-2017 (process 1 of 9)
    Step 1: Collected data.
    Two marine geological surveys were conducted in Nantucket Sound, Massachusetts, in May 2016 and May 2017. The survey vessel occupied one of the target sites and the MiniSEABOSS was deployed off the vessel's starboard side in 2016 and off the vessel's stern in 2017. The MiniSEABOSS was equipped with a modified Van Veen grab sampler, two GoPro HERO4 Black digital cameras (the lower camera acquired bottom photos and the upper camera recorded backup bottom video), an oblique downward-looking SeaViewer 6000 HD Sea-Drop video camera with a topside feed, and a dive light to illuminate the sea floor for video and photograph collection. The elements of this particular MiniSEABOSS system were held within a stainless-steel frame that measured ~1 x 1 meter. 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 MiniSEABOSS 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 photos 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 MiniSEABOSS is at the optimum height (approximately 75 centimeters) off the bottom for a photograph. The winch operator lowered the sampler until the sea floor was observed in the topside live video feed. Generally, the vessel and sampler drifted with wind and current for up to a few minutes to ensure a decent photo with a clear view of the sea floor was acquired. The GoPro camera was set to capture photos every 2 to 5 seconds during a MiniSEABOSS deployment in 2016 and every 1 second in 2017. The photographed area is most often within 0.5 to 1.25 meters from left to right. Bottom video was also recorded during the drift. Then, the winch operator lowered the Van Veen sampler until it rested on the sea floor. When the system was raised, the Van Veen 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 76 sites were occupied with the MiniSEABOSS: 55 sites were occupied aboard the R/V Rafael in May 2016 during field activity 2016-005-FA, and 21 sites were occupied aboard the R/V Tioga in May 2017 during field activity 2017-022-FA. Bottom photographs were collected at all 76 sites. Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
    Data sources produced in this process:
    • Original JPEG photographs
    Date: 2017 (process 2 of 9)
    Step 2: Acquired and processed navigation.
    During field activity 2016-005-FA, DGPS navigation from a Hemisphere DGPS receiver was logged through HYPACK navigation software and a DataBridge data logger. The DGPS was set to receive fixes at a 2-second interval in geographic coordinates (WGS 84). Dates and times were recorded in UTC. Log files for each MiniSEABOSS deployment were saved in text format and then combined for each Julian day. An AWK script (awkseth.gprmc.16005.awk) was used to parse the GPRMC navigation string from the log files and create ASCII Comma Separated Values (CSV) text files. The output files were merged and then reformatted using an AWK script (nav_time_reformat.awk), creating a processed navigation CSV text file for the survey (2016-005-FA_OdysseyAudioStamp_nav_ALL.csv). For field activity 2017-022-FA, a GPS log file in text format for the R/V Tioga was provided by the Woods Hole Oceanographic Institution. The navigation was collected at a 1-second interval in geographic coordinates (WGS 84), and dates and times were recorded in UTC. An AWK script (awksethTioga.gprmc.17022.awk) was used to parse the GPRMC navigation string from the log file, creating a processed navigation CSV text file for the survey (2017022FA_TiogaShip_nav.csv). Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
    Data sources produced in this process:
    • Processed navigation files
    Date: Jul-2018 (process 3 of 9)
    Step 3: Identified camera time offset for photos.
    The original JPEG images do not represent spatial data; however, they were geotagged in a subsequent process step by linking the time the photo 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 photos, the GoPro camera time, which was set to UTC, was 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 navigation system or on the video, which had an overlay of the GPS time) were taken with the GoPro camera so that the camera time could be calibrated to the GPS time during photo processing. These calibration photographs indicated that the camera time was 22 seconds ahead of the GPS time on Julian day 123 and 29 seconds ahead of the GPS time on Julian day 124 during the 2016 survey. Calibration photographs were not available for Julian day 128 in 2016, so two photographs 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 46 seconds ahead of the GPS time. In 2017, calibration photographs indicated that the camera time was 92 seconds behind the GPS time. These time offsets were corrected in a later process step. Since different time offsets were applied to each survey day in 2016, the 2016 bottom photographs were renamed with a prefix of the Julian day (e.g., G0020192.JPG was renamed JD123_G0020192.JPG). This process step and the subsequent process steps were performed by the same person, Emily Huntley. Person who carried out this activity:
    Emily Huntley
    U.S. Geological Survey
    Geographer/Database Specialist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 (voice)
    508-457-2310 (FAX)
    ehuntley@contractor.usgs.gov
    Data sources used in this process:
    • Original JPEG photographs
    Data sources produced in this process:
    • Renamed JPEG photographs
    Date: Dec-2019 (process 4 of 9)
    Step 4: Interpolated to create 1-second navigation.
    The navigation fixes were interpolated to create 1-second navigation. This was done because the application used to geotag the bottom photos would have interpolated between fixes; therefore, before running the application, the navigation was interpolated so that the sediment and imagery data could be mapped using the same 1-second navigation. To interpolate the 2016 navigation data, first, a column of the original source filename was deleted from the processed navigation CSV text file (2016-005-FA_OdysseyAudioStamp_nav_ALL.csv). Next, a shapefile was created from the CSV file in Esri ArcGIS (version 10.3.1) and projected to WGS 84 UTM Zone 19N so that the distance in meters between the navigation fixes could be calculated. Then, the Generate Near Table tool was run using the planar method with the input and output features set to the UTM navigation shapefile and with the option checked to find only the closest feature. The output table was used to identify erroneous fixes, and two erroneous fixes were deleted from the navigation CSV text file. A Jupyter Notebook Python script (Interp_NAV_Dec2019_for_Nantucket2016-005-FA.ipynb) was run to interpolate and create a CSV text file of 1-second navigation. The original 2-second fixes were logged only when the video was recorded, so the script also interpolated between the end point of a video trackline and the start point of the next trackline. To create a final file of 1-second navigation, the points between the video trackline start and end times were extracted (which removed the interpolated positions during the transits between the video tracklines) and were saved as a CSV text file (out_interp_2016Nantucket_sel_for_gpx.csv). The CSV file was reorganized and formatted to have fields of the latitude, longitude, hours, minutes, seconds, Julian day, year, field activity ID, and Julian day and time. Finally, the CSV text file was converted to a GPX file (out_interp_2016Nantucket_sel.gpx), which is a GPS track log file format supported by ExifTool, using GPS Visualizer (http://www.gpsvisualizer.com/convert_input?convert_format=gpx, accessed December 20, 2019). For the 2017 survey, navigation data were logged for the full Julian day, including when the survey vessel was at the dock and when it was transiting to, from, and between the sampling sites. First, the navigation data from 13:30:00 to 19:14:59 were extracted from the processed navigation CSV text file (2017022FA_TiogaShip_nav.csv) to remove the navigation logged at, departing, and returning to the dock. Next, columns of the original source filename and time (the hours, minutes, and seconds were listed individually in other columns) were deleted from the CSV text file, and leading spaces were deleted as needed. Then, a shapefile was created from the CSV file in Esri ArcGIS (version 10.3.1) and projected to WGS 84 UTM Zone 19N so that the distance in meters between the navigation fixes could be calculated. The Generate Near Table tool was run using the planar method with the input and output features set to the UTM navigation shapefile and with the option checked to find only the closest feature. The output table was used to identify erroneous fixes, but no erroneous fixes were identified. The navigation data, however, were noisy. To smooth the data, the coordinates were rounded from seven to six decimal places and every fourth fix was extracted. A Jupyter Notebook Python script (Interp_NAV_Dec2019_for_Nantucket2017-022-FA.ipynb) was run to interpolate and create a CSV text file of 1-second navigation (2017022FA_TiogaShip_nav_4secint_round6_interp_for_gpx.csv). The CSV file was reorganized and formatted to have fields of the latitude, longitude, hours, minutes, seconds, Julian day, year, field activity ID, and Julian day and time to create a final CSV file of 1-second navigation for the survey. Finally, the CSV text file was converted to a GPX file (2017022FA_TiogaShip_nav_4secint_round6_interp.gpx) using GPS Visualizer (http://www.gpsvisualizer.com/convert_input?convert_format=gpx, accessed December 15, 2019). Data sources used in this process:
    • Processed navigation files
    Data sources produced in this process:
    • GPX navigation files
    Date: Feb-2020 (process 5 of 9)
    Step 5: Geotagged the photos and incorporated survey information into the photos' metadata tags.
    The following commands were used with ExifTool (version 11.86) to geotag the photos by populating the GPS tags and to incorporate additional survey information into the appropriate metadata tags of each JPEG image. Since the photos were acquired during two surveys and various time offsets were applied to each Julian day of surveying, different commands were run for each day's photos using slightly different tags. In the commands below, the "-geosync" value 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 photo'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). Survey 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. For more information about the ExifTool commands, see https://exiftool.org/geotag.html and https://exiftool.org/faq.html.
    2016 photos from Julian day 123:
    exiftool -api GeoMaxIntSecs=0 -api GeoMaxExtSecs=0 -P -m -geotag ./out_interp_2016Nantucket_sel.gpx -geosync=-22 '-geotime<${DateTimeOriginal}+00:00' -Artist="Laura L. Brothers" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Caption-Abstract="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Nantucket Sound, Massachusetts, 2016-005-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Rafael during survey 2016-005-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-005-FA)." -Caption="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" ./2016_originals/JD123*
    2016 photos from Julian day 124:
    exiftool -api GeoMaxIntSecs=0 -api GeoMaxExtSecs=0 -P -m -geotag ./out_interp_2016Nantucket_sel.gpx -geosync=-29 '-geotime<${DateTimeOriginal}+00:00' -Artist="Laura L. Brothers" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Caption-Abstract="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Nantucket Sound, Massachusetts, 2016-005-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Rafael during survey 2016-005-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-005-FA)." -Caption="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" ./2016_originals/JD124*
    2016 photos from Julian day 128:
    exiftool -api GeoMaxIntSecs=0 -api GeoMaxExtSecs=0 -P -m -geotag ./out_interp_2016Nantucket_sel.gpx -geosync=-46 '-geotime<${DateTimeOriginal}+00:00' -Artist="Laura L. Brothers" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Caption-Abstract="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Nantucket Sound, Massachusetts, 2016-005-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Rafael during survey 2016-005-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-005-FA)." -Caption="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA" ./2016_originals/JD128*
    2017 photos:
    exiftool -api GeoMaxIntSecs=0 -api GeoMaxExtSecs=0 -P -m -geotag ./2017022FA_TiogaShip_nav_4secint_round6_interp.gpx -geosync=+92 '-geotime<${DateTimeOriginal}+00:00' -Artist="Laura L. Brothers" -Copyright="Public Domain - please credit U.S. Geological Survey" -ImageDescription="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA" -Caption-Abstract="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA" -Contact="WHSC_data_contact@usgs.gov" -CopyrightNotice="Public Domain - please credit U.S. Geological Survey" -Credit="U.S. Geological Survey" -sep ", " -keywords="Nantucket Sound, Massachusetts, 2017-022-FA, SEABOSS, sea floor, USGS" -comment="Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Tioga during survey 2017-022-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-022-FA)." -Caption="Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA" ./2017_originals
    The following tags were populated in the JPEG image headers using the above ExifTool commands:
    GPS tags (these values are unique for each photo 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: Laura L. Brothers
    Copyright: Public Domain - please credit U.S. Geological Survey
    ImageDescription (2016 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA
    ImageDescription (2017 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA
    International Press Telecommunications Council (IPTC) tags and the information used to populate these tags:
    Caption-Abstract (2016 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA
    Caption-Abstract (2017 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA
    Contact: WHSC_data_contact@usgs.gov
    CopyrightNotice: Public Domain - please credit U.S. Geological Survey
    Credit: U.S. Geological Survey
    Keywords (2016 photos): Nantucket Sound, Massachusetts, 2016-005-FA, SEABOSS, sea floor, USGS
    Keywords (2017 photos): Nantucket Sound, Massachusetts, 2017-022-FA, SEABOSS, sea floor, USGS
    JPEG tag and the information used to populate this tag:
    Comment (2016 photos): Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Rafael during survey 2016-005-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-005-FA).
    Comment (2017 photos): Photo from down-looking camera on the USGS SEABOSS deployed from the R/V Tioga during survey 2017-022-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-022-FA).
    Extensible Metadata Platform (XMP) tag and the information used to populate this tag:
    Caption (2016 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2016-005-FA
    Caption (2017 photos): Photograph of the sea floor in Nantucket Sound, Massachusetts, from survey 2017-022-FA
    To extract the information from the photo metadata tags using ExifTool, the following command can be used (tested with ExifTool version 11.86):
    exiftool -csv -f -filename -GPSTimeStamp -GPSDateStamp -GPSLatitude -GPSLongitude -c "%+.7f" -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 -c option formats the latitude and longitude as signed decimal degrees with seven decimal places. Please note that the above command was tested on macOS; Windows users may need to use "exiftool.exe" instead of "exiftool." Data sources used in this process:
    • Original JPEG photographs
    • GPX navigation files
    Data sources produced in this process:
    • JPEG photographs with updated metadata tags
    Date: Feb-2020 (process 6 of 9)
    Step 6: Renamed the photos.
    The photographs were renamed to include the field activity identifier, camera, and GPS date and time in the ISO 8601 standard (YYYYMMDD T [time separator] HHMMSS Z [Zulu/UTC time]) in the filename. Renaming the photos was done by creating a shell script with the original photo name and the new photo name with the GPS date and time information parsed from the photo's Exif metadata tags. Data sources used in this process:
    • JPEG photographs with updated metadata tags
    Data sources produced in this process:
    • Renamed JPEG photographs with updated metadata tags
    Date: Jun-2020 (process 7 of 9)
    Step 7: Culled the photos.
    Photos with no corresponding navigation data, which included 118 photos from the 2016 survey and 99 photos from 2017, were removed from the dataset. Most of these photos were taken on deck or in the water column. Since the photos were captured every 2 to 5 seconds in 2016 and every 1 second in 2017, the remaining bottom photographs were culled to select a few representative photos for each site for publication. To do this, 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 with a clear view of the sea floor. If a site had many photos with a clear view of the sea floor, then a photo generally every 15 to 20 seconds was selected for publication. Navigation was not recorded for site 2016-005-043, so a bottom photograph taken when the MiniSEABOSS was resting on the sea floor was given the coordinates of the closest available fix, which was shortly after the MiniSEABOSS was lifted off the sea floor at the site, using ExifTool and added to the dataset. An additional photo that did not intersect a video trackline was also added to the dataset; one photo that was taken a few seconds before the start of the video trackline at site 2016-005-044 was selected for publication since it had a clear view of the sea floor. Data sources used in this process:
    • Renamed JPEG photographs with updated metadata tags
    Data sources produced in this process:
    • Final JPEG photographs
    Date: Jun-2020 (process 8 of 9)
    Step 8: Created a CSV file of the bottom photo locations.
    The information from the photo metadata tags was extracted using the following ExifTool (version 11.86) command:
    exiftool -csv -f -filename -GPSTimeStamp -DateTimeOriginal -GPSDateStamp -GPSLatitude -GPSLongitude -c "%+.7f" *.JPG > out.csv
    Microsoft Excel 2016 for Mac was used to 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 including an attribute 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 photo (DEVICE_ID), and survey vessel (VEHICLE_ID); and remove additional fields extracted from the ExifTool command. Data sources used in this process:
    • Final JPEG photos
    Data sources produced in this process:
    • Bottom photo locations CSV file
    Date: Jun-2020 (process 9 of 9)
    Step 9: Created a final shapefile and CSV file of the bottom photo locations.
    A shapefile was created from the bottom photos locations CSV file using the XY Table To Point tool in Esri ArcGIS Pro (version 2.4). The Spatial Join tool was then run to calculate the site number (FIELD_NO) and video trackline (LINENAME) for each bottom photo by joining the attributes of the bottom video tracklines shapefile using the intersect match option with a search radius of 0.01 meters. Two of the bottom photos did not intersect a bottom video trackline, so the site number (FIELD_NO) was assigned to the photo and a no data value of -9999 was added to the blank video trackline attribute (LINENAME). 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 Pro and saved as a CSV file. The FID field was deleted in the CSV file. Data sources used in this process:
    • Bottom photo locations CSV file
    • Bottom video tracklines shapefile
    Data sources produced in this process:
    • Final bottom photo locations shapefile
    • Final bottom photo locations CSV file
  3. What similar or related data should the user be aware of?
    Ackerman, Seth D., Brothers, Laura L., Foster, David S., Andrews, Brian D., Baldwin, Wayne E., and Schwab, William C., 2016, High-resolution geophysical data from the inner continental shelf: South of Martha’s Vineyard and north of Nantucket, Massachusetts: Open-File Report 2016–1168, U.S. Geological Survey, Reston, VA.

    Online Links:

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    Sea-floor photos were acquired with a 12-megapixel GoPro HERO4 Black camera using the default settings; file sizes are generally between 2 and 3 MB on disc. Camera time drift and the precision with which the camera time can be set often result in a time offset. The GoPro camera time was set to Coordinated Universal Time (UTC). During photo processing, calibration photographs indicated that, in 2016, the camera time was 22 seconds ahead of the Global Positioning System (GPS) time on Julian day 123, 29 seconds ahead on Julian day 124, and 46 seconds ahead on Julian day 128, and, in 2017, the camera time was 92 seconds behind the GPS time throughout the survey. These time offsets were corrected during photo processing.
  2. How accurate are the geographic locations?
    The original JPEG images alone do not represent spatial data; however, the photos were geolocated during post-processing by linking the time the photo was taken to the corresponding time in the navigation data. Sources of horizontal inaccuracy may be due to the camera time or navigation data. In 2016, the GoPro camera time was 22 seconds ahead of the GPS time on Julian day 123, 29 seconds ahead on Julian day 124, and 46 seconds ahead on Julian day 128. In 2017, the GoPro camera time was 92 seconds behind the GPS time. These time offsets were corrected during photo processing. Navigation for field activity 2016-005-FA used a Differential Global Positioning System (DGPS). The DGPS was set to receive fixes at a 2-second interval in geographic coordinates (World Geodetic System of 1984 [WGS 84]). The fixes were later interpolated to get 1-second navigation. For field activity 2017-022-FA, navigation data for the R/V Tioga from a GPS were provided by the Woods Hole Oceanographic Institution. The 2017 navigation was collected at a 1-second interval in geographic coordinates (WGS 84); however, the navigation data were noisy, so a fix every 4 seconds was extracted and then interpolated to get smoother 1-second navigation. The recorded position of each photograph is the position of the DGPS/GPS antenna on the survey vessel, located on the aft port side of the R/V Rafael's cabin just off the centerline in 2016 and on the forward center of the R/V Tioga's wheelhouse in 2017, not the location of the MiniSEABOSS. The MiniSEABOSS was deployed approximately 2 meters to the starboard side of the DGPS antenna in 2016 and approximately 13 meters aft the GPS antenna in 2017. No layback or offset was applied to the recorded position. In addition, the sampler may drift away from the survey vessel when deployed to the sea floor. Based on the various sources of horizontal offsets, a conservative estimate of the horizontal accuracy of the bottom photograph locations is 2-4 meters in 2016 and 13-15 meters in 2017. Navigation was not recorded for one site (site 2016-005-043), so the photo from this site was mapped at the closest available fix, which was shortly after the MiniSEABOSS was lifted off the sea floor at the site.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This dataset includes geotagged sea-floor photographs in JPEG format and a shapefile and CSV file of the locations of photos collected during field activities 2016-005-FA and 2017-022-FA. Seventy-six sites were occupied within the study area, and bottom photos were acquired at all of the sites with a GoPro HERO4 Black camera mounted on the MiniSEABOSS. Representative photos with a clear view of the sea floor for each site were chosen for publication. Navigation and video were not recorded for one site (site 2016-005-043), so a bottom photograph taken when the MiniSEABOSS was resting on the sea floor and the sediment sample from the site were mapped at the closest available fix, which was shortly after the MiniSEABOSS was lifted off the sea floor at the site. A total of 255 photos for all 76 sites are included in this dataset.
  5. How consistent are the relationships among the observations, including topology?
    Two GoPro HERO4 Black cameras were mounted on the MiniSEABOSS: a lower camera, which acquired bottom photos, and an upper camera, which recorded backup bottom video. All bottom photographs were acquired with the lower GoPro camera. The lower GoPro camera also acquired additional backup video on the first survey day (Julian day 123) in 2016, so the photos collected that day have a different dimension (3840 x 2160) from the photos acquired during the remaining survey days (4000 x 3000). The GoPro camera was set to capture photos every 2 to 5 seconds during a MiniSEABOSS deployment in 2016 and every 1 second in 2017. Gaps in sequential photo numbers exist because representative photos with a clear view of the sea floor for each site were chosen for publication. Navigation and video were not recorded for one site (site 2016-005-043), so a bottom photograph taken when the MiniSEABOSS was resting on the sea floor and the sediment sample from the site were mapped at the closest available fix, which was shortly after the MiniSEABOSS was lifted off the sea floor at the site; the bottom photo from this site has a different time offset than the offset applied to the other photos taken on the same day. An additional photo that did not intersect a video trackline was also included in this dataset: one photo that was taken a few seconds before the start of the video trackline at site 2016-005-044 was selected for publication since it had a clear view of the sea floor.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? Geotagged sea-floor photographs and location of bottom photographs collected in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey during field activities 2016-005-FA and 2017-022-FA. This dataset contains the following files: a shapefile of the bottom photo locations (2016-005-FA_and_2017-022-FA_photos.shp); a CSV file of the bottom photo locations (2016-005-FA_and_2017-022-FA_photos.csv); 255 geotagged bottom photos from a GoPro HERO4 Black camera in a zip file (2016-005-FA_and_2017-022-FA_jpg.zip); a browse graphic of bottom photo locations (2016-005-FA_and_2017-022-FA_photos_browse.jpg); and a Federal Geographic Data Committee (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM) metadata file (2016-005-FA_and_2017-022-FA_photos_meta.xml).
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    This dataset contains data available as a point shapefile, a CSV file, and JPEG image files. The user must have software capable of reading shapefile format to use the point shapefile. The CSV file can be read with a text editor. An image viewer can be used to see the JPEG images.

Who wrote the metadata?

Dates:
Last modified: 16-Nov-2020
Metadata author:
Emily Huntley
U.S. Geological Survey
Geographer/Database Specialist
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 (voice)
508-457-2310 (FAX)
ehuntley@contractor.usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9UK5IOF/2016-005-FA_and_2017-022-FA_photos_meta.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:19:41 2021