USGS CoastCam at Sand Key, Florida: Intrinsic and Extrinsic Calibration Data (Camera 1)

The CoastCam was used to take IO photos. This involves slightly tilting a printed checkerboard with 2.7-centimeter (cm) squares in various parts of the cameras field of view. An example image can be found in sandkey_c1_calibrationIOEO_exampleImagery.zip. There are a total of 29 IO images (sandkey_c1_20180413_IO.zip) used for the intrinsic calibration. These 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 sandkey_c1_20180413_IO.zip. Image file naming format follows “sandkey_c1_20180413_IO_##”, where sandkey is the site name, c1 is the camera name, 20180413 is the date the images were taken (YYYYMMDD format), IO is Intrinsic Orientation, and ## is the original unique ID from the camera.

Extrinsic orientation (EO) calibration ground control points (GCPs) were surveyed with a Spectra Precision SP80 Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver. GCPs were collected on 20180419. To place the photos taken by the CoastCam into real world coordinates and to rectify them into a planar view, objects within the field of view of the camera must be located. To do so, the elevation and position of the camera lenses in the CoastCam setup were measured with the RTK GPS. Then, a single large square target (1.2 m by 1.2 m) painted white and black in opposite quadrants was propped up to face the CoastCam setup at multiple locations within the camera field-of-view to collect ground control points. At each GCP location, a snapshot was taken with the camera of the position of the target (sandkey_c1_20180419_GCP##.jpg); additionally, the bottom-center of the target (between black and white, at ground level) was measured with the RTK GPS equipment. A single image showing all GCP locations (sandkey_c1_20180419_GCP_image_raw.jpg) was made by creating a “dark” image using all of the snapshots of the GCP target. The survey locations of the GCPs in the CSV file was used to hand label the raw image to generate an annotated image (sandkey_c1_20180419_GCP_image_annotated.jpg) 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 (hand-selected at bottom-center of targets), solved in Step B of Bruder and Brodie (2020), the GPS 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 “sandkey_c1_20180419_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: 0.5.6). 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': UserComment, 'GPSLatitude': '27.9391', 'GPSLongitude': '-82.8393', '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/P146YVZF ', 'Contributor': 'Jenna A. Brown, Justin J. Birchler, Margaret L. Palmsten, Eric Swanson, Emily L. Johnson, Mark Buckley', 'XMP-photoshop:Credit': 'U.S. Geological Survey', 'iptcCore:CreatorWorkEmail': 'gs-g-spcmsc_data_inquiries@usgs.gov','Rights': 'Public Domain', 'Keywords' : "Sand Key, Florida, CoastCam, USGS, intrinsic calibration, snapshot, remote sensing ", 'ImageDescription': 'This image was captured from a stationary mounted camera at Sand Key, Florida. Field Activity Number: 2018-302-DD (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-302-DD) Other FANs referenced in calibration metadata: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-328-FA, 'Description': 'This image was captured from a stationary mounted camera at Sand Key, Florida. Field Activity Number: 2018-302-DD (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-302-DD) Other FANs referenced in calibration metadata: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-328-FA}. 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: 0.5.6). 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': UserComment, 'GPSLatitude': '27.9391', 'GPSLongitude': '-82.8393', '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/P146YVZF ', 'Contributor': 'Jenna A. Brown, Justin J. Birchler, Margaret L. Palmsten, Eric Swanson, Emily L. Johnson, Mark Buckley', 'XMP-photoshop:Credit': 'U.S. Geological Survey', 'iptcCore:CreatorWorkEmail': 'gs-g-spcmsc_data_inquiries@usgs.gov','Rights': 'Public Domain', 'Keywords' : "Sand Key, Florida, CoastCam, USGS, extrinsic calibration, remote sensing, ground control point", 'ImageDescription': 'This image was captured from a stationary mounted camera at Sand Key, Florida. Field Activity Number: 2018-302-DD (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-302-DD) Other FANs referenced in calibration metadata: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-328-FA, 'Description': 'This image was captured from a stationary mounted camera at Sand Key, Florida. Field Activity Number: 2018-302-DD (https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-302-DD) Other FANs referenced in calibration metadata: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-328-FA}. 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.