Metadata: Identification_Information: Citation: Citation_Information: Originator: Christine J. Kranenburg Originator: Andrew C. Ritchie Originator: Jenna A. Brown Originator: Jin-Si R. Over Originator: Daniel Buscombe Originator: Christopher R. Sherwood Originator: Jonathan A. Warrick Originator: Phillipe A. Wernette Publication_Date: 20201130 Title: Post-Hurricane Florence Aerial Imagery: Cape Fear to Duck, North Carolina, October 6-8, 2018 Geospatial_Data_Presentation_Form: remote-sensing image Series_Information: Series_Name: U.S. Geological Survey Data Release Issue_Identification: doi:10.5066/P91KB9SF Publication_Information: Publication_Place: St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P91KB9SF Description: Abstract: The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three-dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods. These products are valuable for measuring topographic change, and for understanding coastal vulnerability and response to disturbance events. A nadir (vertical) aerial imagery survey was conducted from Cape Fear to Duck, North Carolina on October 6-8, 2018, in response to Hurricane Florence. The observations along the coastline cover an area approximately 275 kilometers long and 300 to 700 meters (m) wide and encompass both highly developed towns as well as natural undeveloped areas, including the federal lands of Cape Lookout National Seashore and Cape Hatteras National Seashore. Low-altitude (300 m above ground level) digital aerial imagery were acquired from a manned, fixed-wing Piper P28A aircraft using a Sony A7R 36 Megapixel digital camera, along with precise aircraft navigation Global Navigation Satellite System (GNSS) data. Data were collected in shore-parallel lines, flying at approximately 50 meters per second (m/s) and capturing true color imagery at 1 Hertz (Hz), resulting in image footprints with approximately 75-80% endlap, 60-70% sidelap, and 5.3-centimeter (cm) ground sample distance (GSD). The precise time of each image capture (flash event) was recorded, and the corresponding aircraft position was computed in post-processing from the aircraft navigation GNSS data; precise image positions can then be determined by accounting for the lever arm offsets between the aircraft GNSS antenna and the camera lens. Position data, provided as latitude/longitude/ellipsoid height, is referenced to the North American Datum of 1983 (NAD83 (2011)). Purpose: These 37,456 aerial images were collected over multiple days along the coast of the Outer Banks, North Carolina, with sufficient resolution and endlap/sidelap to produce Structure-from-Motion (SfM) photogrammetry products in order to observe coastal impacts due to Hurricane Florence. Supplemental_Information: These data were collected by the USGS Coastal and Marine Hazards and Resources Program under the USGS field activity number (FAN) 2018-303-CNT, and the associated field activity web page contains additional information regarding the field activity: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-303-CNT. Aerial imagery was collected over multiple days in order to cover the entire survey area; acquisition was timed to coincide with low tide along the beach areas to ensure maximum shoreline extent was captured. Bounding coordinates for the aerial survey are derived from the overall flight path and are not necessarily representative of the imagery coverage. Time_Period_of_Content: Time_Period_Information: Multiple_Dates/Times: Single_Date/Time: Calendar_Date: 20181006 Single_Date/Time: Calendar_Date: 20181007 Single_Date/Time: Calendar_Date: 20181008 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -78.1627583734 East_Bounding_Coordinate: -75.4610244200 North_Bounding_Coordinate: 36.2191029662 South_Bounding_Coordinate: 33.8314148703 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:41b0f06b-9c3d-4fad-9a3e-13c1a76f1257 Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: remote sensing Theme_Keyword: aerial photography Theme_Keyword: image collections Theme_Keyword: geospatial datasets Theme_Keyword: coastal processes Theme_Keyword: geomorphology Theme_Keyword: hurricanes Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: hurricane Theme_Keyword: aerial imagery Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme_Keyword: imageryBaseMapsEarthCover Theme_Keyword: oceans Place: Place_Keyword_Thesaurus: Geographic Names Information Service (GNIS) Place_Keyword: North Carolina Place_Keyword: Outer Banks Place_Keyword: Cape Hatteras National Seashore Place_Keyword: Cape Lookout National Seashore Place_Keyword: Cape Fear Temporal: Temporal_Keyword_Thesaurus: None Temporal_Keyword: October 2018 Temporal_Keyword: Post-Hurricane Florence Access_Constraints: none Use_Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator of the dataset and in products derived from these data. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine J. Kranenburg Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: 2018-10_NC_RegionalMap.jpg (https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AreaMaps.zip) Browse_Graphic_File_Description: Regional map of survey area along the Outer Banks, North Carolina, during USGS field activity 2018-303-CNT. Browse_Graphic_File_Type: JPG Browse_Graphic: Browse_Graphic_File_Name: 2018-10_NC_Area1.jpg (https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AreaMaps.zip) Browse_Graphic_File_Description: This map, found within the zip file listed above, shows the extent of Area 1 in the regional map for the post-Hurricane Florence aerial images from Cape Fear, North Carolina, to Topsail Beach, North Carolina. The flight paths were divided into 3-minute latitudinal segments, represented by alternating purple and yellow lines, and images for each segment are contained in zip files named according to the four-digit latitude (degree/minute) of the southern boundary. Browse_Graphic_File_Type: JPG Browse_Graphic: Browse_Graphic_File_Name: 2018-10_NC_Area2.jpg (https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AreaMaps.zip) Browse_Graphic_File_Description: This map, found within the zip file listed above, shows the extent of Area 2 in the regional map for the post-Hurricane Florence aerial images from New Inlet, North Carolina, to the North Core Banks of Cape Lookout National Seashore, North Carolina. The flight paths were divided into 3-minute latitudinal segments, represented by alternating purple and yellow lines, and images for each segment are contained in zip files named according to the four-digit latitude (degree/minute) of the southern boundary. Some segments are further divided to limit the zip files to 20 GB and are identified by labels (a-e); all portions of a segment must be downloaded to ensure full coverage. Browse_Graphic_File_Type: JPG Browse_Graphic: Browse_Graphic_File_Name: 2018-10_NC_Area3.jpg (https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AreaMaps.zip) Browse_Graphic_File_Description: This map, found within the zip file listed above, shows the extent of Area 3 in the regional map for the post-Hurricane Florence aerial images from the North Core Banks of Cape Lookout National Seashore, North Carolina, to Avon, North Carolina. The flight paths were divided into 3-minute latitudinal segments, represented by alternating purple and yellow lines, and images for each segment are contained in zip files named according to the four-digit latitude (degree/minute) of the southern boundary. Some segments are further divided to limit the zip files to 20 GB and are identified by labels (a-e); all portions of a segment must be downloaded to ensure full coverage. Browse_Graphic_File_Type: JPG Browse_Graphic: Browse_Graphic_File_Name: 2018-10_NC_Area4.jpg (https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AreaMaps.zip) Browse_Graphic_File_Description: This map, found within the zip file listed above, shows the extent of Area 4 in the regional map for the post-Hurricane Florence aerial images from Avon, North Carolina, to Duck, North Carolina. The flight paths were divided into 3-minute latitudinal segments, represented by alternating purple and yellow lines, and images for each segment are contained in zip files named according to the four-digit latitude (degree/minute) of the southern boundary. Some segments are further divided to limit the zip files to 20 GB and are identified by labels (a-e); all portions of a segment must be downloaded to ensure full coverage. Browse_Graphic_File_Type: JPG Data_Set_Credit: Data collection was funded by the U.S. Geological Survey. The authors would like to thank pilot Wayne Wright of C.W. Wright Consulting for data acquisition and systems expertise. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The accuracy of the position data is based on the accuracy of the post-processed aircraft navigation data, which produced a 1-Hz aircraft trajectory with an estimated 2-sigma accuracy of 10 cm horizontal and 15 cm vertical for the October 7 and 8, 2018 surveys. In-aircraft electronic interference degraded the accuracy of the aircraft trajectory positions to an estimated value of 5 m on October 6, 2018. Note that the positions in the image EXIF headers are aircraft GNSS antenna positions and are limited to six decimal places, whereas the positions in the external navigation file are accurate to ten decimal places and are therefore highly recommended for use in SfM processing to produce the highest quality derived products. Logical_Consistency_Report: All data fall within expected ranges. Completeness_Report: This dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the entire metadata record carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Positions provided in the aircraft navigation file (2018-10_NC_AircraftPositions.txt) have an estimated 2-sigma horizontal accuracy of 10 cm for images collected on October 7 and 8, 2018. Positions in the same file for images collected on October 6, 2018 have an estimated horizontal accuracy of 5 m. The accuracy of the positions in the image EXIF headers are reduced due to field size limitations for storing latitude/longitude. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Positions provided in the aircraft navigation file (2018-10_NC_AircraftPositions.txt) have an estimated 2-sigma vertical accuracy of 15 cm for images collected on October 7 and 8, 2018. Positions in the same file for images collected on October 6, 2018 have an estimated vertical accuracy of 5 m. Lineage: Process_Step: Process_Description: IMAGE ACQUISITION A nadir (vertical) aerial imagery survey was conducted from Cape Fear to Duck, North Carolina on October 6-8, 2018, in response to Hurricane Florence, by C. W. Wright Consulting using a Sony A7R 36 Megapixel digital camera aboard a Piper P28A aircraft. Data were collected in shore-parallel lines, flying at approximately 50 m/s and capturing true color imagery at 1 Hz, resulting in image footprints with approximately 75-80% endlap, 60-70% sidelap, and 5.3-cm GSD. A total of 37,456 raw (ARW) images, raw dual-frequency carrier phase GNSS data and photo event time data were delivered to the USGS St. Petersburg Coastal and Marine Science Center. Process_Date: 20181008 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine J. Kranenburg Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Position: Cartographer Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Process_Step: Process_Description: AIRCRAFT NAVIGATION PROCESSING Raw GNSS data received by the antenna mounted atop the aircraft were recorded at 1 Hz by a dual-frequency survey-grade GNSS receiver, which was post-processed and differentially corrected with no fewer than 5 continuously operating reference stations (CORS) in Novatel's GrafNav software (v. 8.80) to produce 1-Hz aircraft trajectories. The aircraft trajectories, in combination with precisely recorded image capture (flash event) times, are used to generate aircraft GNSS antenna positions at the moment of each image capture (2018-10_NC_AircraftPositions.txt). The positions in the aircraft navigation file represent the position of the aircraft GNSS antenna, not the position of the camera or features photographed. To determine actual image positions, photogrammetric software such as Agisoft Metashape can be used to apply the lever arm offsets (in the camera frame of reference) from the GNSS antenna reference point to the camera lens, which are 0.1 m, -0.15 m, and 1.25 m, in the x, y, and z directions respectively. Process_Date: 20200326 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine J. Kranenburg Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Position: Cartographer Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Process_Step: Process_Description: IMAGE PROCESSING & SAVING Images were received from the vendor in Sony RAW (ARW) format and converted to Joint Photographic Experts Group (JPEG or JPG) format using Adobe Camera Raw (v. 12.2.1) and applying the Camera Neutral Profile. Image file names represent capture date, time stamp, and ancillary data, using the following convention: yyyy-mmdd-hhmmss-DSCnnnnn-N7251F.jpg where yyyy_mmdd represents the year (yyyy), month (mm) and day (dd) of capture; hhmmss is the time of capture as hours (hh), minutes (mm), seconds(ss) in UTC; DSCnnnnn represents a sequential image ID generated by the camera; and N7251F is the tail number of the aircraft used for acquisition. Process_Date: 20200620 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Andrew R. Ritchie Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Position: Geologist Contact_Address: Address_Type: Physical and Mailing Address: 2885 Mission St. City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: USA Contact_Voice_Telephone: 831-460-7454 Contact_Electronic_Mail_Address: aritchie@usgs.gov Process_Step: Process_Description: IMAGE EXIF & SORTING Georeferencing, copyright, and other relevant information was added to the EXIF header of each photo using Phil Harvey’s ExifTool (v. 11.88). To extract the information from the image headers using ExifTool, the following command can be used (tested with ExifTool version 11.88): exiftool -csv -f -filename -GPSDateStamp -GPSTimeStamp -GPSLongitude -GPSLatitude -n -Artist -Credit -comment -keywords -Caption -Copyright -CopyrightNotice -Caption-Abstract -ImageDescription directoryname/*.jpg > out.csv The -csv flag writes the information out in a comma-delimited format. The -n option formats the latitude and longitude as signed decimal degrees. Images are sorted by latitude and contained within zip files according to 3-minute latitude segments of the coast (labeled based on the southern latitude boundary in degrees (DD) and minutes (mm) North (N), and further subdivided (labeled as -a/b/c/d/e) as needed to limit the overall file size. Process_Date: 20200820 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine J. Kranenburg Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Position: Cartographer Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20201130 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Arnell S. Forde Contact_Position: Geologist Contact_Address: Address_Type: Mailing and Physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: aforde@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Pixel Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 (2011) Ellipsoid_Name: GRS 1980 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257223563 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: 2018-10_NC_AircraftPositions.txt Entity_Type_Definition: The space-separated American Standard Code for Information Interchange (ASCII) text file, 2018-10_NC_AircraftPositions.txt, is included within 2018-10_NC_AircraftPositions.zip and contains the post-processed aircraft navigation GNSS data (position of the aircraft at the moment of each image capture). Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: ImageName Attribute_Definition: File names of individual aerial images; see the Lineage section and IMAGE PROCESSING & SAVING Process_Description for file naming convention details. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2018-1006-135256-DSC04179-N7251F.jpg Range_Domain_Maximum: 2018-1008-194045-DSC00296-N7251F.jpg Attribute: Attribute_Label: Latitude Attribute_Definition: Latitude of aircraft GNSS antenna position at the moment of each image capture, in decimal degrees (NAD83). Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 33.8314148703 Range_Domain_Maximum: 36.2191029662 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Longitude Attribute_Definition: Longitude of aircraft GNSS antenna position at the moment of each image capture, in decimal degrees (NAD83). Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -75.4610244200 Range_Domain_Maximum: -78.1627583734 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Altitude Attribute_Definition: Altitude of aircraft GNSS antenna position at the moment of each image capture, in m above the (NAD83) datum. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 209.700 Range_Domain_Maximum: 359.264 Overview_Description: Entity_and_Attribute_Overview: Aerial Imagery (2018-10_NC_DDmmN-a/b/c/d/e.zip) - Individual aerial images are available in JPG format and are contained within zip files; see the Lineage section and IMAGE EXIF & SORTING Process_Step for more information on file naming and image sorting conventions. Entity_and_Attribute_Overview: Aircraft Navigation Data (2018-10_NC_AircraftPositions.zip) - The zip file contains a text (TXT) file of the precise post-processed GNSS position of the aircraft at the precise flash event time of each image; see the Entity_and_Attribute_Information section and Detailed_Description for more information on the variables reported in the TXT file, and see the Lineage section and AIRCRAFT NAVIGATION PROCESSING Process_Step for information on how to compute the precise image positions from the aircraft positions using photogrammetric software and applying lever arm offsets between the aircraft GNSS antenna and camera lens. Entity_and_Attribute_Overview: Area Maps (2018-10_NC_AreaMaps.zip) - The zip file contains a regional map and detailed Area maps, available in JPG format, of individual coastline segments corresponding to the aerial imagery zip files within each survey subset area; see the Identification_Information section and Browse_Graphic text for additional information about the maps. Entity_and_Attribute_Detail_Citation: The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: SPCMSC Data Management Group Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Address: Address_Type: Physical and Mailing Address: 600 4th St South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: gs-g-spcmsc_data_inquiries @usgs.gov Distribution_Liability: This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: JPEG Format_Information_Content: JPEG images can be opened directly with any JPEG-compatible image viewer. Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/ Access_Instructions: Aerial imagery, available in JPG format, can be downloaded per segment of coastline as zipped files from the data table of the data release page at the Network_Resource_Name link. The following link can also be modified and used to directly obtain the data files: https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_DDmmN(-a/b/c/d/e).zip, where DDmmN represents the southern boundary of the 3-degree latitude segment in degrees (DD) and minutes (mm) North (N), and the labels -a/b/c/d/e are to further subdivide the segment as needed to limit the overall file sizes. Digital_Form: Digital_Transfer_Information: Format_Name: TXT Format_Information_Content: TXT files can be opened directly with any text-editing software. Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P91KB9SF/data/2018-10_NC_AircraftPositions.zip Access_Instructions: Aircraft navigation data, available in TXT format, can be downloaded as a zip file from the Network_Resource_Name link. Fees: None. Metadata_Reference_Information: Metadata_Date: 20201130 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine J. Kranenburg Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Position: Cartographer Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998