Metadata: Identification_Information: Citation: Citation_Information: Originator: Joshua B. Logan Originator: Eric E. Grossman Originator: Nathan R. VanArendonk Publication_Date: 20210915 Title: Topographic point cloud for the intertidal zone at Lone Tree Point, Kiket Bay, WA, 2019-06-05 Geospatial_Data_Presentation_Form: point cloud digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9TO24SR 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/P9TO24SR Online_Linkage: https://www.sciencebase.gov/catalog/item/5ef5228582ced62aaae6a013 Larger_Work_Citation: Citation_Information: Originator: Joshua B. Logan Originator: Eric E. Grossman Originator: Nathan R. VanArendonk Publication_Date: 2021 Title: Aerial imagery and structure-from-motion data products from UAS survey of the intertidal zone at Lone Tree Point, Kiket Bay, WA, June 2019 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9TO24SR 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/P9TO24SR Online_Linkage: https://www.sciencebase.gov/catalog/item/5f2c591682ceae4cb3c2d030 Description: Abstract: This portion of the data release presents a topographic point cloud of the intertidal zone at Lone Tree Point, Kiket Bay, WA. The point cloud was derived from structure-from-motion (SfM) processing of aerial imagery collected with an unmanned aerial system (UAS) on 2019-06-05. The point cloud has 206,323,353 points with an average point density of 929 points per-square meter. The point cloud is tiled to reduce individual file sizes and is grouped within a zip file for downloading. Each point in the point cloud contains an explicit horizontal and vertical coordinate, color, intensity, and classification. Water portions of the point cloud were classified using a polygon digitized from the orthomosaic imagery derived from these surveys (also available in this data release). No other classifications were performed. The raw imagery used to create these point clouds was acquired using a UAS fitted with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines. The camera was triggered at 1 Hz using a built-in intervalometer. The UAS was flown at an approximate altitude of 70 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 1.8 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Eighteen temporary ground control points (GCPs) were distributed throughout the survey area to establish survey control. The GCPs consisted of a combination of small square tarps with black-and-white cross patterns and "X" marks placed on the ground using temporary chalk. The GCP positions were measured using post-processed kinematic (PPK) GPS, using corrections from a GPS base station located approximately 16 kilometers from the study area. The point clouds are formatted in LAZ format (LAS 1.2 specification). Purpose: These data were collected to characterize the morphology, substrate composition and roughness of intertidal areas to support modeling of coastal storm and wave impacts with sea-level rise as part of the USGS Puget Sound Coastal Storm Modeling System (PS-CoSMoS). The data are also intended to be used to model and evaluate sediment transport and its effects on coastal habitats, a focus of the USGS Coastal Habitats in Puget Sound Project (CHIPS) and its partners to inform resource management and adaptive planning for our Nation's coasts. 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=2019-623-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: 20190605 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: -122.55652 East_Bounding_Coordinate: -122.55186 North_Bounding_Coordinate: 48.41205 South_Bounding_Coordinate: 48.40420 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Bathymetry and Elevation 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: 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: Unmanned aerial system Theme_Keyword: UAS Theme_Keyword: Structure-from-motion Theme_Keyword: SfM Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5ef5228582ced62aaae6a013 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: State of Washington Place_Keyword: Swinomish Reservation Place_Keyword: Lone Tree Point Place_Keyword: Skagit County Place_Keyword: Salish Sea Place_Keyword: Kiket Bay Place_Keyword: Skagit Bay 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/5ef5228582ced62aaae6a013?name=LoneTreePoint_2019-06-05_pointcloud_browse.jpg&allow=openTrue Browse_Graphic_File_Description: Perspective view of the Lone Tree Point topographic point cloud from the 2019-06-05 UAS survey. Browse_Graphic_File_Type: JPEG Native_Data_Set_Environment: Microsoft Windows 10, Agisoft PhotoScan version 1.4.4 through Agisoft Metashape 1.5.3, ESRI ArcGIS 10.6 through 10.7, Exiftool, Geosetter 3.4.16, QGIS 3.04 through 3.12, and LAStools ver. 190417. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted. Logical_Consistency_Report: No formal logical accuracy tests were conducted. 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: Horizontal accuracy was estimated by comparing SfM-derived ground control point (GCP) positions to PPK GPS measurements. Due to the time-intensive process of placing GCPs in the field, all available GCPs were used for registration and camera optimization in the SfM processing workflow during the creation of the final point clouds. To evaluate the horizontal positional accuracy of the point cloud after processing was completed, each GCPs was disabled one-at-a-time using a python script to create a 'temporary check point'. With a single GCP temporarily disabled, camera optimization was performed with all lens parameters fixed, and all other GCPs enabled. The residual errors of the check point relative to its GPS-measured position were recorded. After all temporary check point iterations were complete, the root-mean-square error (RMSE) and mean-absolute error (MAE) were calculated. The resulting horizontal RMSE was 0.019 meters (MAE 0.016 meters). The addition of the estimated horizontal GPS uncertainty (0.020 meters) in quadrature results in a total horizontal accuracy estimate of 0.028 meters for the point cloud. It should be noted that this error estimate is for areas of bare ground or low vegetation where GCPs were placed. Additional sources of error such as poor image-to-image point matching due to vegetation or uniform substrate texture (such as sand) resulting in poor surface reconstruction may cause localized errors in some portions of the point clouds to exceed this estimate. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Vertical accuracy was estimated by comparing SfM-derived ground control point (GCP) positions to PPK GPS measurements. Due to the time-intensive process of placing GCPs in the field, all available GCPs were used for registration and camera optimization in the SfM processing workflow during the creation of the final point cloud. To evaluate the vertical positional accuracy of the point cloud after processing was completed, each GCPs was disabled one-at-a-time using a python script to create a 'temporary check point'. With a single GCP temporarily disabled, camera optimization was performed with all lens parameters fixed, and all other GCPs enabled. The residual errors of the check point relative to its GPS-measured position were recorded. After all temporary check point iterations were complete, the root-mean-square error (RMSE) and mean-absolute error (MAE) were calculated. The resulting vertical RMSE was 0.037 meters (MAE 0.028 meters). The addition of the estimated vertical GPS uncertainty (0.025 meters) in quadrature results in a total vertical accuracy estimate of 0.045 meters for the point cloud. It should be noted that this error estimate is for areas of bare ground or low vegetation where GCPs were placed. Additional sources of error such as poor image-to-image point matching due to vegetation or uniform substrate texture (such as sand) resulting in poor surface reconstruction may cause localized errors in some portions of the point clouds to exceed this estimate. 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 camera was mounted using a fixed mount on the bottom of the UAS and oriented in an approximately nadir orientation. For flights F01, F02, F03, and F04, the UAS was flown on pre-programmed autonomous flight lines at an approximate altitude of 70 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 1.8 centimeters per pixel. The flight lines were oriented roughly shore-parallel and were spaced to provide approximately 70 percent overlap between images from adjacent lines. For flight F05, the UAS was flown manually to acquire imagery over areas not mapped in the previous flights. The camera was triggered at 1 Hz using a built-in intervalometer and were programmed to simultaneously acquire imagery in both JPG and camera raw (Adobe DNG) formats. Before each flight, the camera digital ISO, aperture and shutter speed were manually set to adjust for ambient light conditions. Although these settings were changed between flights, they were not permitted to change during a flight; thus, the images from each flight were acquired with consistent camera settings. Process_Date: 20190605 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: Ground control was established using ground control points (GCPs) consisting of small square tarps with black-and-white cross patterns and temporary chalk 'X' marks placed on the ground surface throughout the survey area. The GCP positions were measured using survey-grade GPS receivers operating in post-processed-kinematic (PPK) mode. The GPS receivers were placed on short fixed-height tripods and set to occupy each GCP for a minimum occupation time of one minute. The PPK corrections were referenced to a Continuously Operating Reference (CORS) GPS base station ('SKGT') located approximately 16 kilometers from the study area operated by the Washington State Reference Network (WSRN). Process_Date: 20190605 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 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 a custom Python script which processes the GPS data from the UAS telemetry log and calls the command-line 'exiftool' software. 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, + 00:00:01 (1 second) was added to the image timestamp to synchronize with corrected 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 intertidal zone at Lone Tree Point, Kiket Bay, Washington, USA, from USGS survey 2019-623-FA." ^ -Caption-Abstract="Intertidal zone at Lone Tree Point, Kiket Bay, Washington, USA, from USGS survey 2019-623-FA." ^ -Caption="Aerial image of the intertidal zone at Lone Tree Point, Kiket Bay, Washington, USA, from USGS survey 2019-623-FA." ^ -sep ", " ^ -keywords="Marine Nearshore Intertidal, Lone Tree Point, Swinomish Reservation, Kiket Bay, Washington, 2019-623-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 2019-623-FA." ^ -Credit="U.S. Geological Survey" ^ -Contact="pcmsc_data@usgs.gov" ^ -Artist="U.S. Geological Survey, Pacific Coastal and Marine Science Center" Process_Date: 2019 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 Process_Step: Process_Description: Structure-from-motion (SfM) processing techniques were used to create the point clouds in the Agisoft Photoscan/Metashape software package using the following workflow: 1. Initial image alignment was performed with the following parameters - Accuracy: 'high'; Pair selection: 'reference', 'generic'; Key point limit: 0 (unlimited); Tie point limit: 0 (unlimited). 2. Sparse point cloud error reduction was performed using an iterative gradual selection and camera optimization process with the following parameters: Reconstruction Uncertainty: 10; Projection Accuracy: 3. Lens calibration parameters f, cx, cy, k1, k2, k3, p1, and p2 were included in the optimization. Additional sparse points obviously above or below the true surface were manually deleted after the last error reduction iteration. 3. Ground control points (GCPs) were automatically detected using the 'Cross (non-coded)' option. False matches were manually removed, and all markers were visually checked and manually placed or adjusted if needed. Markers were manually placed for GCPs that consisted of chalk 'X' marks. 4. Additional sparse point cloud error reduction was performed using an iterative gradual selection and camera optimization process with the following parameters: Reconstruction Error: 0.3. Lens calibration parameters f, cx, cy, k1, k2, k3, p1, and p2 were initially included in the optimization, but additional parameters k4, b1, b2, p3, and p4 were included once Reconstruction Error was reduced below 1 pixel. Additional sparse points obviously above or below the true surface were manually deleted after the last error reduction iteration, and a final optimization was performed. 5. A dense point cloud was created using the 'high' accuracy setting, with 'aggressive' depth filtering. 6. A Digital Surface Model (DSM) with a native resolution of 3.7 centimeters per pixel was created using all points in the dense point cloud, and was exported to a GeoTIFF format with a 4-centimeter pixel resolution. 7. An RGB orthomosaic with a native resolution of 1.84 centimeters per pixel was created using the main DSM as the orthorectification surface, and was exported to a GeoTIFF format with a 2-centimeter pixel resolution. 8. An exterior boundary was digitized using the orthomosaic as a reference and was used as a clipping mask to exclude areas of water, obvious edge artifacts, and large areas of interpolation. 9. The point clouds were exported in LAZ format. 10. LAStools 'lasclip' was used to set the classification of all points falling within the horizontal bounds of the water clipping mask shapefile as Class 9 ('water'). Process_Date: 2019 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 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 10 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: 0.001 Ordinate_Resolution: 0.001 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: NAD83 (National Spatial Reference System 2011) (EPSG:1116) Ellipsoid_Name: GRS 1980 (EPSG:7019) Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 (EPSG:5703), derived using GEOID12B Altitude_Resolution: 0.001 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The attribute information associated with point cloud follows the LAZ file standard. Attributes include location (northing, easting, and elevation in the NAD83(2011)/UTM zone 10N (EPSG:6339) horizontal and NAVD88 vertical coordinate systems), color (red, blue, and green components), intensity, and classification. All points are classified as 0 (unclassified) or 9 (water). Entity_and_Attribute_Detail_Citation: American Society for Photogrammetry and Remote Sensing (ASPRS; 2013, https://www.asprs.org/committee-general/laser-las-file-format-exchange-activities.html) and Isenburg (2013, https://doi.org/10.14358/PERS.79.2.209) 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 topographic point clouds are available as LAZ files. 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: LAZ Format_Version_Number: LAS 1.2 Format_Information_Content: These zip files contain point cloud data in LAZ format (LAS 1.2 specification). File_Decompression_Technique: Zip Transfer_Size: 1520 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5ef5228582ced62aaae6a013?name=LoneTreePoint_2019-06-05_pointcloud.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5ef5228582ced62aaae6a013 Network_Resource_Name: https://doi.org/10.5066/P94LH20J Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to a zip file containing the main survey area point clouds in LAZ format. The second link points to a landing page with the point cloud, metadata, and a browse image. The third link points to the landing page for the entire data release, including links to pages of the various data files. Fees: None. Technical_Prerequisites: This zip file contains point cloud data in LAZ format (LAS 1.2 specification). The user must have software capable of uncompressing the .zip compressed file and displaying or processing the .laz format file. Metadata_Reference_Information: Metadata_Date: 20210915 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