Metadata: Identification_Information: Citation: Citation_Information: Originator: Joshua B. Logan Originator: Curt D. Storlazzi Publication_Date: 20220321 Title: Aerial imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Geospatial_Data_Presentation_Form: JPEG Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9XZT1FK Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P9XZT1FK Online_Linkage: https://www.sciencebase.gov/catalog/item/61957726d34eb622f69093a1 Larger_Work_Citation: Citation_Information: Originator: Joshua B. Logan Originator: Curt D. Storlazzi Publication_Date: 2022 Title: Aerial imagery and structure-from-motion-derived shallow water bathymetry from a UAS survey of the coral reef off Waiakane, Molokai, Hawaii, June 2018 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9XZT1FK Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P9XZT1FK Online_Linkage: https://www.sciencebase.gov/catalog/item/61943c39d34eb622f68f530c Description: Abstract: This portion of the data release presents raw aerial imagery collected during an unoccupied aerial system (UAS) survey of the coral reef off Waiakane, Molokai, Hawaii, on 24 June 2018. The imagery was acquired using a Department of Interior-owned 3DR Solo quadcopter fitted with a Ricoh GR II digital camera featuring a global shutter. The camera was mounted in a nadir orientation using a fixed mount. Before each flight, the camera’s digital ISO, aperture, and shutter speed were adjusted for ambient light conditions. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 75 percent overlap between images from adjacent lines. The UAS was flown at an approximate altitude of 100 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.6 centimeters per pixel. The camera was triggered at 1 Hz using a built-in intervalometer. A total of five flights were conducted for the survey between 16:40 and 17:45 UTC (06:40 and 07:45 HST). Flight F01 was a reconnaissance flight, and no mapping imagery was collected. Flights F02 and F03 were conducted at an approximate altitude of 100 meters above ground level (AGL), resulting in complete coverage of the mapping area with a nominal ground-sample-distance (GSD) of approximately 2.5 centimeters per pixel. Flights F04 and F05 were conducted using the same flight lines and altitudes of F02 and F03, but the camera was fitted with a circular polarizing filter to reduced reflections and provide improved imaging of the seafloor through the water surface. After acquisition, the images were renamed to include flight number and acquisition time in the file name. The coordinates of the approximate image acquisition location were added ('geotagged') to the image metadata (EXIF) using the telemetry log from the UAS onboard single-frequency autonomous GPS. The image EXIF was also updated to include additional information related to the acquisition. Although the images were recorded in both JPG and camera raw (Adobe DNG) formats, only the JPG images are provided in this data release. The data release includes a total of 1,665 JPG images. Images from takeoff and landing sequences were not used for processing and have been omitted from the data release. The images from each flight are provided in a zip file named with the flight number. The zip files containing the imagery collected with the circular polarizing filter are named with '_CPF' to distinguish them from the files with imagery collected without a filter. Purpose: These data were collected to characterize the morphology and rugosity of the shallow fringing coral reef off Waiakane, Molokai, Hawaii, as part of a larger USGS study of nearshore circulation and hydrodynamic properties of coral reefs. The orthomosaic images can be used with geographic information systems (GIS) software for research purposes. Supplemental_Information: Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-617-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20180624 Currentness_Reference: ground condition at time data were collected Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -157.15679 East_Bounding_Coordinate: -157.15388 North_Bounding_Coordinate: 21.09352 South_Bounding_Coordinate: 21.08451 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: imageryBaseMapsEarthCover Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Substrate Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: topography Theme_Keyword: topographic maps Theme_Keyword: remote sensing Theme_Keyword: geomorphology Theme_Keyword: aerial photography Theme_Keyword: image mosaics Theme_Keyword: geospatial datasets Theme_Keyword: structure from motion Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: photography Theme_Keyword: remote sensing Theme_Keyword: aerial and satellite photography Theme_Keyword: altimetry Theme_Keyword: orthophotography Theme_Keyword: coastal processes Theme_Keyword: reef Theme_Keyword: fringing reef Theme_Keyword: coral reefs 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: CHMRP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Theme_Keyword: UAS Theme_Keyword: Unmanned aerial system Theme_Keyword: Structure-from-motion Theme_Keyword: SfM Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:61957726d34eb622f69093a1 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: State of Hawaii Place_Keyword: Molokai Place_Keyword: Maui County Place_Keyword: Waiakane Place_Keyword: Kalohi Channel 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(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/61957726d34eb622f69093a1?name=F3_20180624T171308Z_RB017518.JPG&allowOpen=True Browse_Graphic_File_Description: Example aerial image from the Waiakane UAS survey. Browse_Graphic_File_Type: JPEG Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The Ricoh GR II cameras used to acquire these images produce a nominal image size of 16.2 megapixels in both JPG and camera raw (Adobe DNG) image formats. The image acquisition time stamp is recorded to the image metadata (EXIF) with a precision of 1 second. The UAS onboard GPS is a single-frequency autonomous receiver which records positions to the telemetry log at 1 second intervals, with an approximate accuracy of 3 meters horizontally and 10 meters vertically. The geotagging operation uses the image time stamp to derive the image acquisition location by finding the nearest location recorded at the time of acquisition. To reduce the potential for timing errors during the geotagging process, the image time stamps were adjusted to true ('corrected') UTC time by comparing the image time stamps with several images taken of a smartphone app ('Emerald Time') showing accurate time from Network Time Protocol (NTP) servers. For this survey, + 00:00:02 (2 seconds) were added to the image time to synchronize with corrected UTC time. The adjusted time stamp was only used for geotagging; the original image time stamp was retained in the image EXIF and file name. The positions stored in the EXIF are in the WGS84 (G1150) coordinate reference system (EPSG:7660), with elevation in meters relative to the WGS84 ellipsoid. Logical_Consistency_Report: Photographs were renamed using a custom python script to include flight number, image acquisition date and time in Universal Coordinated Time (UTC), camera ID, and original image ID number. The image EXIF were also updated to include additional information related to the acquisition. Some photographs may be auto-rotated by certain viewing software, but the original image orientation is the same for all images. Completeness_Report: Five flights were conducted with during the survey. Flights F01 was for reconnaissance purposes and no mapping imagery was collected. The imagery from each flight was stored separately, and the flights were renamed for organizational purposes. The camera shutter was triggered at 1 Hz by a built-in intervalometer which was started before takeoff and stopped after landing. Images from the takeoff and landing sequences were not used in data processing and are not included in this data release. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal positions stored in the EXIF image metadata were derived with a 'geotagging' process using the image time stamps and the uncorrected positions recorded in the telemetry log of the UAS from the onboard single-frequency autonomous GPS (mRobotics GPS u-Blox Neo-M8N / 3DR SOLO Upgrade). To reduce the potential for timing errors during the geotagging process, the image time stamps were adjusted to true ('corrected') UTC time by comparing the image time stamps with several images taken of a smartphone app ('Emerald Time') showing accurate time from Network Time Protocol (NTP) servers. The horizontal positions are estimated to be accurate to approximately 3 meters. However, it should be noted that for some images the error may exceed this estimate due to GPS errors or timing errors associated with the geotagging process. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The vertical positions stored in the EXIF image metadata were derived with a 'geotagging' process using the image time stamps and the uncorrected positions recorded in the telemetry log of the UAS from the onboard single-frequency autonomous GPS (mRobotics GPS u-Blox Neo-M8N / 3DR SOLO Upgrade). To reduce the potential for timing errors during the geotagging process, the image time stamps were adjusted to true ('corrected') UTC time by comparing the image time stamps with several images taken of a smartphone app ('Emerald Time') showing accurate time from Network Time Protocol (NTP) servers. The horizontal positions are estimated to be accurate to approximately 10 meters. However, it should be noted that for some images the error may exceed this estimate due to GPS errors or timing errors associated with the geotagging process. Lineage: Process_Step: Process_Description: Aerial imagery was collected using a Department of Interior-owned 3DR Solo quadcopter fitted with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines which were oriented roughly shore-normal and were spaced to provide approximately 75 percent overlap between images from adjacent lines, at an approximate altitude of 100 meters above ground level (AGL). The camera was triggered at 1 Hz using a built-in intervalometer. Before each flight, the camera’s digital ISO, aperture, and shutter speed were adjusted for ambient light conditions. A total of five flights were conducted for the survey between 16:40 and 17:45 UTC (06:40 and 07:45 HST). Flight F01 was a reconnaissance flight, and no mapping imagery was collected during the flight. Flights F02 and F03 were conducted at an approximate altitude of 100 meters above ground level (AGL), resulting in complete coverage of the mapping area with a nominal ground-sample-distance (GSD) of approximately 2.5 centimeters per pixel. Flights F04 and F05 were conducted using the same flight lines and altitudes of F02 and F03, but the camera was fitted with a circular polarizing filter to reduced reflections and provide improved imaging of the seafloor through the water surface. Only the images collected without the polarizing filter (F02 and F03) were used for the creation of the orthomosaic presented in this data release. Process_Date: 20180624 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joshua Logan Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: US Contact_Voice_Telephone: 831-460-7519 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: jlogan@usgs.gov Process_Step: Process_Description: The image files were renamed using a custom python script. The file names were formed using the following pattern Fx-YYYYMMDDThhmmssZ_Ryz.*, where: - Fx = Flight number - YYYYMMDDThhmmssZ = date and time in the ISO 8601 standard, where 'T' separates the date from the time, and 'Z' denotes UTC ('Zulu') time. - Ry = RA or RB to distinguish camera 'RicohA' from 'RicohB' - z = original image name assigned by camera during acquisition - * = file extension (JPG or DNG) The approximate image acquisition coordinates were added to the image metadata (EXIF) ('geotagged') using the image timestamp and the telemetry logs from the UAS onboard single-frequency 1-Hz autonomous GPS. The geotagging process was done using the GeoSetter software package. To improve timestamp accuracy, the image acquisition times were adjusted to true ('corrected') UTC time by comparing the image timestamps with several images taken of a smartphone app ('Emerald Time') showing accurate time from Network Time Protocol (NTP) servers. For this survey, + 00:00:02 (2 seconds) were added to the image timestamp to synchronize with UTC time. The positions stored in the EXIF are in geographic coordinates referenced to the WGS84(G1150) coordinate reference system (EPSG:7660), with elevation in meters relative to the WGS84 ellipsoid. Additional information was added to the EXIF using the command-line 'exiftool' software with the following command: exiftool ^ -P ^ -Copyright="Public Domain. Please credit U.S. Geological Survey." ^ -CopyrightNotice="Public Domain. Please credit U.S. Geological Survey." ^ -ImageDescription="Low-altitude aerial image of the shallow coral reef off Waiakane, Molokai, HI, USA, from USGS Unmanned Aircraft System (UAS) survey 2018-617-FA." ^ -Caption-Abstract="Coral reef off Waiakane, Molokai, HI, USA, from USGS survey 2018-617-FA." ^ -Caption="Aerial image of the shallow coral reef off Waiakane, Molokai, HI, USA, from USGS Unmanned Aircraft System (UAS) survey 2018-617-FA." ^ -sep ", " ^ -keywords="coral reef, Molokai, Maui County, Hawaii, Waiakane, 2018-617-FA, Unmanned Aircraft System, UAS, drone, aerial imagery, U.S. Geological Survey, USGS, Pacific Coastal and Marine Science Center" ^ -comment="Low-altitude aerial image from USGS Unmanned Aircraft System (UAS) survey 2018-617-FA." ^ -Credit="U.S. Geological Survey" ^ -Contact="pcmsc_data@usgs.gov" ^ -Artist="U.S. Geological Survey, Pacific Coastal and Marine Science Center" Process_Date: 2018 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joshua Logan Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7519 Contact_Electronic_Mail_Address: jlogan@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Pixel Row_Count: 3264 Column_Count: 4352 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: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257224 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: WGS84 Ellipsoid Altitude_Resolution: 0.01 Altitude_Distance_Units: meters Altitude_Encoding_Method: Attribute values Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: There are no additional attributes besides the tags described in data quality section associated with these images. Entity_and_Attribute_Detail_Citation: USGS Field Activity 2018-617-FA Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing address Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Country: United States Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: The aerial images from four flights conducted during the UAS survey are available in JPG format. The images from each flight are combined into a zip file with the flight number in the file name. Distribution_Liability: 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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: JPEG Format_Information_Content: Zipped files contain geotagged aerial images acquired during a UAS survey by the U.S. Geological Survey. File_Decompression_Technique: WinZip, 7zip, Peazip or pkUnzip Transfer_Size: 3.12 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/61957726d34eb622f69093a1?name=F02_Waiakane_2018-06-24_JPG_images.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/61957726d34eb622f69093a1?name=F03_Waiakane_2018-06-24_JPG_images.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/61957726d34eb622f69093a1?name=F04_Waiakane_2018-06-24_JPG_images_CPF.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/61957726d34eb622f69093a1?name=F05_Waiakane_2018-06-24_JPG_images_CPF.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/61957726d34eb622f69093a1 Network_Resource_Name: https://doi.org/10.5066/P9XZT1FK Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first four links are direct links to the zip files with the images from each flight. Transfer sizes of the zip files range between 1.5 GB to 3.12 GB. The fifth link points to a landing page with the image zip files, metadata, and a browse image. The last link points to the landing page for the entire data release, including links to pages of the various data files. Fees: None. Technical_Prerequisites: The downloadable data files are available in zipped JPG file format. Image processing and viewing software can be used to open and view the files. Metadata_Reference_Information: Metadata_Date: 20220321 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998