USGS CoastCam at Tres Palmas, Rincón, Puerto Rico: Intrinsic and Extrinsic Calibration Data

The CoastCam was used to take IO photos. This involves slightly tilting a printed checkerboard with 30-millimeter (mm) squares in various parts of the cameras field of view. An example image can be found in TresPalmasPR_c2_20190721_calibrationIOEO_exampleImagery.zip. There are a total of 54 IO images (TresPalmasPR_c2_20190719_IO.zip) of which 38 were used for the intrinsic calibration. The 38 images were used in step A in the Camera Calibration procedures outlined in Bruder and Brodie (2020). The resultant parameters are stored in a YAML file located in TresPalmasPR_c2_20190719_IO.zip. Image file naming format follows “TresPalmasPR_c2_20190719_##.jpg”, 2019-07-19 is the date that the images were taken (YYYYMMDD format) and #### is the original unique ID from the camera.

Extrinsic orientation (EO) calibration ground control points (GCPs) were surveyed with a Topcon GRS-1 survey-grade dual-frequency GNSS receiver set to record raw GNSS observables in Post-Processed Kinematic (PPK) mode. To place the photos taken by the CoastCam into real world coordinates and to rectify them into a planar view, objects (GCPs) within the field of view of the camera must be located. Multiple GCPs painted orange and black in opposite quadrants were stationed within the field of view of the CoastCam. The GNSS receiver was placed on a fixed-height survey rod and set to record observations for one minute at each ground control point at the center of each target (between black and orange). One receiver, serving as a base station, was placed on a fixed-height rod and affixed to a stable object approximately 250 meters from the survey area. The base receiver was programmed to record raw GNSS observations during survey operations. After completion of the survey, the NovAtel Waypoint Grafnav software package was used to derive coordinates for the base reference position using Precise Point Positioning (PPP). After the surveys, the raw recorded GNSS observations were converted from proprietary format to the standard RINEX format using the TEQC software package. The Trimble Business Center ver. 5.00 software package was then used to post process the data using the PPK post processing technique. The CoastCam took pictures of the position of each target within the camera view (raw JPEG image). The CSV file was used to hand label the raw images to generate annotated images so that the targets could be labeled correctly in Step B of the Camera Calibration steps in Bruder and Brodie (2020). The pixel coordinates of each GCP within the raw images, solved in Step B of Bruder and Brodie (2020), the GNSS positions from the CSV files, and the IO parameters in the IO YAML file were used in Step C of the Camera Calibration steps in Bruder and Brodie (2020) to solve for the EO parameters. The resultant parameters for the EO calibration are stored in a YAML file located in “TresPalmasPR_c2_20190721_EO.zip”.

All intrinsic calibration images were given additional information required by the USGS to the exchangeable image file format (EXIF) and other imagery headers using PyExifTool Python library (https://pypi.org/project/PyExifTool/, version: 0.5.5). All intrinsic photos were given EXIF header information in the directory with all the photos by assigning all the tags in a Python dictionary object to each photo using PyExifTool. The following describes the Python dictionary object with each entry in the dictionary being a tag-value pair: tags = { 'Copyright': 'Public Domain', 'CopyrightNotice': 'Public Domain - please credit U.S. Geological Survey', 'Artist': 'USGS SPCMSC', 'Make': 'FLIR','Model': 'BFLY-PGE-50S5C-C','UserComment': ‘The following nested dictionary contains the cameras intrinsic and extrinsic calibration parameters. Intrinsic camera parameters use the Brown distortion model (Brown, D.C., 1971. "Close-Range Camera Calibration." Photogrammetric Engineering), using the Camera Calibration Toolbox for Matlab by Jean-Yves Bouguet (https://doi.org/10.22002/D1.20164). Extrinsic calibration parameters were computed using the CIRN Quantitative Coastal Imaging Toolbox (Bruder, B. L. and Brodie, K. L., 2020, "CIRN Quantitative Coastal Imaging Toolbox.", SoftwareX 12 (10052), https://doi.org/10.1016/j.softx.2020.100582.)’, 'GPSLatitude': '18.34810272', 'GPSLongitude': '-67.26319029', 'GPSMapDatum': 'EPSG:6318 (NAD83_National_Spatial_Reference_System_2011)', 'GPSLatitudeRef': 'N', 'GPSLongitudeRef': 'W', 'GPSDateStamp': '2019-07-19', 'Credit': 'U.S. Geological Survey', 'Contact': 'gs-g-spcmsc_data_inquiries@usgs.gov', '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", 'AttributionURL': 'https://doi.org/10.5066/P142AXUJ', 'ExternalMetadataLink': 'https://www1.usgs.gov/pir/api/identifiers/USGS:2cc439a0-ce48-49df-bc9f-78e8fa85b0f2', 'Contributor': 'Shawn R. Harrison, Mark L. Buckley, Cordell Johnson, Daniel J. Nowacki, Miguel Canals, Colin Evans, Joshua Logan, Curt D. Storlazzi, Justin J. Birchler, Margaret L. Palmsten, Eric Swanson, Emily L. Johnson', 'XMP-photoshop:Credit': 'U.S. Geological Survey', 'iptcCore:CreatorWorkEmail': 'gs-g-spcmsc_data_inquiries@usgs.gov','Rights': 'Public Domain', 'Keywords' : "Tres Palmas, Rincón, Puerto Rico, CoastCam, USGS, intrinsic calibration, snapshot, remote sensing, ground control point", 'ImageDescription': 'This image was captured from a stationary mounted camera at Tres Palmas, Rincón, Puerto Rico. Field Activity Number: 2019-675-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-675-FA)', 'Description': 'This image was captured from a stationary mounted camera at Tres Palmas, Rincón, Puerto Rico. Field Activity Number: 2019-675-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-675-FA)'}. If there were errors generating keywords with the Python script, additional keywords were added to the imagery headers for all of the IO images using the following command: 'exiftool -sep ", " -iptc:keywords="Tres Palmas, Rincón, Puerto Rico, CoastCam, USGS, intrinsic calibration" *.jpg'. The UserComment EXIF metadata field was used to store the camera intrinsics and extrinsics in the image metadata. The UserComment has a nested dictionary structure. The highest-level dictionary contains two nested dictionaries as well as a note explaining the structure of the UserComment field. One nested dictionary contains the actual intrinsic and extrinsic data variables. The other nested dictionary contains text descriptions for each of the variables in the dictionary of data variables. To read out the imagery header information to a CSV file the command is: 'exiftool -csv *.jpg > allheaders.csv'. Specific tags may be specified with this command, if preferred.

All extrinsic calibration ground control point images were given additional information required by the USGS to the exchangeable image file format (EXIF) and other imagery headers using PyExifTool Python library (https://pypi.org/project/PyExifTool/, version: 0.5.5). All extrinsic photos were given EXIF header information in the directory with all the photos by assigning all the tags in a Python dictionary object to each photo using PyExifTool. The following describes the Python dictionary object with each entry in the dictionary being a tag-value pair: tags = { 'Copyright': 'Public Domain', 'CopyrightNotice': 'Public Domain - please credit U.S. Geological Survey', 'Artist': 'USGS SPCMSC', 'Make': 'FLIR','Model': 'BFLY-PGE-50S5C-C','UserComment': ‘The following nested dictionary contains the cameras intrinsic and extrinsic calibration parameters. Intrinsic camera parameters use the Brown distortion model (Brown, D.C., 1971. "Close-Range Camera Calibration." Photogrammetric Engineering), using the Camera Calibration Toolbox for Matlab by Jean-Yves Bouguet (https://doi.org/10.22002/D1.20164). Extrinsic calibration parameters were computed using the CIRN Quantitative Coastal Imaging Toolbox (Bruder, B. L. and Brodie, K. L., 2020, "CIRN Quantitative Coastal Imaging Toolbox.", SoftwareX 12 (10052), https://doi.org/10.1016/j.softx.2020.100582.)', 'GPSLatitude': '18.34810272', 'GPSLongitude': '-67.26319029', 'GPSMapDatum': 'EPSG:6318 (NAD83_National_Spatial_Reference_System_2011)', 'GPSLatitudeRef': 'N', 'GPSLongitudeRef': 'W', 'Credit': 'U.S. Geological Survey', 'Contact': 'gs-g-spcmsc_data_inquiries@usgs.gov', '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", 'AttributionURL': 'https://doi.org/10.5066/P142AXUJ', 'ExternalMetadataLink':'https://www1.usgs.gov/pir/api/identifiers/USGS:2cc439a0-ce48-49df-bc9f-78e8fa85b0f2', 'Contributor': 'Shawn R. Harrison, Mark L. Buckley, Cordell Johnson, Daniel J. Nowacki, Miguel Canals, Colin Evans, Joshua Logan, Curt D. Storlazzi, Justin J. Birchler, Margaret L. Palmsten, Eric Swanson, Emily L. Johnson', 'XMP-photoshop:Credit': 'U.S. Geological Survey', 'iptcCore:CreatorWorkEmail': 'gs-g-spcmsc_data_inquiries@usgs.gov','Rights': 'Public Domain', 'Keywords' : "Tres Palmas, Rincón, Puerto Rico, CoastCam, USGS, intrinsic calibration, snapshot, remote sensing, ground control point", 'ImageDescription': 'This image was captured from a stationary mounted camera at Tres Palmas, Rincón, Puerto Rico. Field Activity Number: 2019-675-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-675-FA', 'Description': 'This image was captured from a stationary mounted camera at Tres Palmas, Rincón, Puerto Rico. Field Activity Number: 2019-675-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-675-FA)'}. If there were errors generating keywords with the Python script, additional keywords were added to the imagery headers for all of the IO images using the following command: 'exiftool -sep ", " -iptc:keywords="Tres Palmas, Rincón, Puerto Rico, CoastCam, USGS, extrinsic calibration" *.jpg'. The only tag which can have a different value from image to image is GPSDateStamp. Depending on the date the photo was captured, the value in the GPSDatestamp tag changes. The UserComment EXIF metadata field was used to store the camera intrinsics and extrinsics in the image metadata. The UserComment has a nested dictionary structure. The highest-level dictionary contains two nested dictionaries as well as a note explaining the structure of the UserComment field. One nested dictionary contains the actual intrinsic and extrinsic data variables. The other nested dictionary contains text descriptions for each of the variables in the dictionary of data variables. To read out the imagery header information to a CSV file the command is: 'exiftool -csv *.jpg > allheaders.csv'. Specific tags may be specified with this command, if preferred.