Metadata: Identification_Information: Citation: Citation_Information: Originator: Evan T. Dailey Publication_Date: 2018 Title: Structure-from-Motion (SfM) surface models derived from seafloor video from the Channel Islands, California Geospatial_Data_Presentation_Form: TIFF Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P929SXZE 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/P929SXZE Online_Linkage: https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c Description: Abstract: Structure-from-Motion (SfM) surface models were created using seafloor video collected over a visible fault scarp in the Channel Islands, California, during a 2016 U.S. Geological Survey (USGS) field activity. Four SfM surface models were created, each with a different combination of locating, scaling, and optimizing methods. Video imagery was collected using the USGS Pacific Coastal and Marine Science Center's BOBSled, equipped with high-definition (720p) video cameras (video published in Coastal and Marine Geology Program video and photo portal, Golden and others, 2015). The sled was towed behind the R/V Shearwater and shipboard GPS locations were recorded every 1 second in the video's audio channel. The models were geolocated and scaled using either shipboard GPS or georeferencing the imagery to existing sonar bathymetry at a lower resolution (Cochrane and others, 2018). The models were optimized using either a fixed lens model or automatic calibration in the SfM software, and the files presented here are named to reflect their processing method: "AutoCal" refers to automatic calibration by the SfM software; "Cal" refers to image calibration using a fixed lens model; "Georef" refers to locations derived from georeferencing the video imagery to the existing sonar data; and "ShipGPS" refers to locations derived from the shipboard GPS embedded in the video. Each file was created using one of each of the calibration and location methods, indicated in the filename as "SfM_CalibrationMethod_LocationMethod_UTM10N." Purpose: These surface models were produced to assess the accuracy and precision of different Structure-from-Motion workflows. Supplemental_Information: Additional information about the field activity from which these data were derived is available online at: http://cmgds.marine.usgs.gov/fan_info.php?fan=2016-668-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20160925 Ending_Date: 20160929 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -120.275 East_Bounding_Coordinate: -120.27 North_Bounding_Coordinate: 34.011 South_Bounding_Coordinate: 34.009 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5bae6310e4b08583a5d30f7c Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: oceans Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Bathymetry and Elevation Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: bathymetry Theme_Keyword: bathymetry measurement Theme_Keyword: sea-floor characteristics Theme_Keyword: geospatial datasets Theme_Keyword: marine geophysics Theme_Keyword: remote sensing Theme_Keyword: videography Theme_Keyword: image mosaics Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: seabed Theme_Keyword: data processing Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: CMGP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Channel Islands National Park Place_Keyword: Channel Islands Place_Keyword: Pacific Ocean 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. 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: 831-460-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c?name=SfM_AutoCal-ShipGPS_vert.png&allowOpen=true Browse_Graphic_File_Description: Image map of the SfM elevation model created using automatic calibration and shipboard GPS locations Browse_Graphic_File_Type: PNG Data_Set_Credit: Data collection was funded by U.S. Geological Survey Native_Data_Set_Environment: Microsoft Windows 7 Service Pack 1 with Esri ArcGIS version 10.5.0.6491 Cross_Reference: Citation_Information: Originator: Guy R. Cochrane Originator: David P. Finlayson Originator: Evan T. Dailey Publication_Date: 2018 Title: Bathymetry data collected in 2007 from the San Miguel Passage in the Channel Islands, California Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/F78G8HVC 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/F78G8HVC Cross_Reference: Citation_Information: Originator: Nadine E. Golden Originator: Seth D. Ackerman Originator: Evan T. Dailey Publication_Date: 2015 Title: Coastal and Marine Geology Program video and photograph portal Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/F7JH3J7N 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/F7JH3J7N Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The horizontal and vertical accuracies of the surface models were compared against existing sonar data (Cochrane and others, 2018). The scale accuracy of the surface models was compared by measuring the camera sled's scale laser as it appeared in the original still frames and the still frames after being aligned and located in the SfM software. Logical_Consistency_Report: All data fall within expected ranges. Completeness_Report: Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Assessing the true horizontal accuracy of the models is prone to uncertainty because they were compared against lower-resolution sonar data. The sonar data had a horizontal accuracy of no less than 2 m. The horizontal accuracy of the SfM models ranged from approximately 0 to 5 m as compared to the sonar data. Overall horizontal accuracy is assumed to be no less than 2 m and no greater than 10 m. The average horizontal scaling of all the models is estimated to be accurate to within 1.25 cm, and 0.15 on average in the model created using shipboard GPS and automatic calibration. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Estimated to be 0.6 meters different than the sonar data, on average. The sonar data had a vertical accuracy estimated to be no less than 5 percent water depth. The average vertical scaling of all the models is estimated to be accurate to within 1.25 cm, and 0.15 on average in the model created using shipboard GPS and automatic calibration. Lineage: Process_Step: Process_Description: Data Collection: Video was collected during USGS field activity 2016-668-FA in the Channel Islands, CA. Video footage was collected using the USGS camera sled, which was equipped with two high resolution video cameras, one pointing downward (vertical) and the other pointing slightly forward (oblique) and was towed by the research vessel Shearwater. The camera sled was also equipped with paired lasers to provide scaling to features on the seafloor. Video was recorded in depths approximately 10 to 70 meters. Shipboard GPS locations were recorded every 1 second into one of the audio channels of the video using Red Hen Systems, LLC hardware. Process_Date: 201801 Process_Step: Process_Description: Structure-from-Motion Processing: Still frames were extracted from the video at a constant rate of 1 frame every 2/3 second. For the shipboard GPS method 6 markers were selected throughout the video imagery. Those markers were assigned latitude and longitude values from the shipboard GPS according to the playback time of that video frame, and the markers were assigned the depth from the existing sonar that corresponded to that location. For the georeferencing method, features visible in the video imagery were georeferenced to that feature where it was visible in the sonar data (7 markers were assigned this way). A lens model was developed using the BOBSled cameras to record imagery of a calibration board in a salt-water tank. That imagery was used to create a model, and the SfM software's lens model was exported as the fixed lens model. Automatic calibration by the SfM software was also used. Four models were produced: calibrated using a fixed lens model with the shipboard GPS that was embedded in the audio ("SfM_Cal-ShipGPS_UTM10N.tif"), lens model auto-calibrated by the SfM software with ship GPS ("SfM_AutoCal-ShipGPS_UTM10N.tif"), calibrated using a fixed lens model with locations derived from georeferencing the video imagery to the existing sonar bathymetry ("SfM_Cal-Georef_UTM10N.tif"), and auto-calibrated with georeferenced locations ("SfM_AutoCal-Georef_UTM10N.tif"). SfM models were created using Agisoft PhotoScan version 1.3.5. Photos were aligned in PhotoScan, iteratively 'cleaned' to reduce error using the following steps in PhotosScan: all points with reconstruction uncertainty greater than 10 were deleted (iteratively - no more than 50 percent of the models points were deleted at a time); all points with projection accuracy greater than 3 were deleted; reprojection error was reduced to 0.3 by iteratively deleting no more than 10 percent of the models points; after each of the previous steps, cameras were optimized; a dense point cloud was created in PhotoScan; digital elevation model created from dense point cloud in PhotoScan; elevation model exported as TIF image. Process_Date: 20180108 Process_Step: Process_Description: Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Process_Date: 20201019 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 10N Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -123.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.00422002 Ordinate_Resolution: 0.00422002 Planar_Distance_Units: METERS Geodetic_Model: Horizontal_Datum_Name: WGS_1984_UTM_Zone_10N Ellipsoid_Name: WGS 84 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257223563 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: MLLW Altitude_Resolution: 1.0E-4 Altitude_Distance_Units: Meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Attribute table Entity_Type_Definition: Table containing attribute information associated with the dataset Entity_Type_Definition_Source: U.S. Geological Survey Attribute: Attribute_Label: Value Attribute_Definition: Depth relative to mean lower low water (MLLW) in meters Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -28.6 Range_Domain_Maximum: -36.0457 Attribute_Units_of_Measure: Meters Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: Mailing and Physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: These data are available in TIFF format (SfM_AutoCal-Georef_UTM10N.tif, SfM_Cal-Georef_UTM10N.tif, SfM_AutoCal-ShipGPS_UTM10N.tif, SfM_Cal-ShipGPS_UTM10N.tif) contained in a single zip file which also includes CSDGM FGDC-compliant metadata, and a browse image map of the data (.jpg). The TIFF data files are named with the following convention: SfM, calibration method, location method, and projected coordinate system. 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: TIFF Format_Version_Number: Agisoft PhotoScan Professional Version 1.3.5 build 5649 (64 bit) Format_Information_Content: The .zip file contains four TIFF rasters (.tif), a browse image map, and the metadata. File_Decompression_Technique: No compression applied. Transfer_Size: 1264.68 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c Network_Resource_Name: https://doi.org/10.5066/P929SXZE Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data and metadata. The second link points to a landing page with metadata and data Fees: None. Technical_Prerequisites: These data can be viewed with Esri ArcGIS software. Metadata_Reference_Information: Metadata_Date: 20201019 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: 831-460-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998