Digital Surface Models (DSM) from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA, July 2021

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Joshua B. Logan
Originator: Andrew W. Stevens
Originator: Cordell D. Johnson
Publication_Date: 20230623
Title:
Digital Surface Models (DSM) from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA, July 2021
Geospatial_Data_Presentation_Form: GeoTIFF
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9BVTVAW
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/P9BVTVAW
Online_Linkage:
https://www.sciencebase.gov/catalog/item/62e470b4d34e749ac04cb783
Larger_Work_Citation:
Citation_Information:
Originator: Joshua B. Logan
Originator: Andrew W. Stevens
Originator: Shawn R. Harrison
Originator: Cordell D. Johnson
Publication_Date: 2023
Title:
Aerial imagery and structure-from-motion data products from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9BVTVAW
Publication_Information:
Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA
Publisher: U.S. Geological Survey
Other_Citation_Details:
Suggested Citation: Logan, J.B., Stevens, A.W., Harrison, S.R., and Johnson, C.D., 2023, Aerial imagery and structure-from-motion data products from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA: U.S. Geological Survey data release, https://doi.org/10.5066/P9BVTVAW.
Online_Linkage: https://doi.org/10.5066/P9BVTVAW
Description:
Abstract:
This portion of the data release presents digital surface models (DSM) of the ocean beach at Fort Stevens State Park, OR, and Benson Beach at Cape Disappointment State Park, WA. The DSMs have resolutions of 10 centimeters per pixel and were derived from structure-from-motion (SfM) processing of aerial imagery collected with unoccupied aerial systems (UAS) during low tides on 22 and 23 July 2021. Unlike a digital elevation model (DEM), the DSMs represent the elevation of the highest object within the bounds of a cell. Vegetation, buildings, and other objects have not been removed from the data. The raw imagery used to create the DSMs was acquired with 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 120 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 3.2 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency post-processed kinematic (PPK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) processing to create topographic point clouds, high-resolution orthomosaic images, and DSMs. The DSMs, which are presented in this portion of the data release have been formatted as cloud optimized GeoTIFFs with internal overviews and masks to facilitate cloud-based queries and display.
Purpose:
These data were obtained to evaluate changes in shoreline position and coastal morphology. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify topographic features on the sub-aerially exposed portions of the beaches surveyed.
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=2021-632-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:
Multiple_Dates/Times:
Single_Date/Time:
Calendar_Date: 20210722
Single_Date/Time:
Calendar_Date: 20210723
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: -124.08829
East_Bounding_Coordinate: -123.99237
North_Bounding_Coordinate: 46.29986
South_Bounding_Coordinate: 46.19996
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:
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:
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:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:62e470b4d34e749ac04cb783
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: State of Washington
Place_Keyword: State of Oregon
Place_Keyword: Pacific Ocean
Place_Keyword: Columbia River
Place_Keyword: Clatsop County
Place_Keyword: Pacific County
Place_Keyword: Cape Disappointment
Place_Keyword: Fort Stevens
Place_Keyword: Benson Beach
Place_Keyword: Clatsop Spit
Place_Keyword: North Head
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/62e470b4d34e749ac04cb783?name=FortStevens_BensonBeach_2021-07_DSM_browse.jpg&allowOpen=true
Browse_Graphic_File_Description: Color-shaded relief of DSMs from July 2021 UAS surveys.
Browse_Graphic_File_Type: JPEG
Native_Data_Set_Environment:
Microsoft Windows 10, Agisoft Metashape 1.6.x through 1.8.x, Exiftool, QGIS 3.26, and GDAL 3.5.1
Cross_Reference:
Citation_Information:
Originator: Joshua B. Logan
Originator: Phillipe A. Wernette
Originator: Andrew C. Ritchie
Publication_Date: 2022
Title:
Agisoft Metashape/Photoscan Automated Image Alignment and Error Reduction version 2.0
Other_Citation_Details:
Logan, J.B., Wernette, P.A. and Ritchie, A.C., 2022, Agisoft Metashape/Photoscan Automated Image Alignment and Error Reduction version 2.0: U.S. Geological Survey code repository, U.S. Geological Survey software release, python package, Reston, Va., (https://doi.org/10.5066/P9DGS5B9).
Online_Linkage: https://doi.org/10.5066/P9DGS5B9
Cross_Reference:
Citation_Information:
Originator: Andrew W. Stevens
Originator: Heather M. Weiner
Originator: Jeffrey M. Wood
Originator: Peter Ruggiero
Originator: George M. Kaminsky
Originator: Guy R. Gelfenbaum
Publication_Date: 2021
Title:
Beach topography and nearshore bathymetry of the Columbia River littoral cell, Washington and Oregon (ver. 3.0, December 2021)
Other_Citation_Details:
Stevens, A.W., Weiner, H.M., Wood, J.M., Ruggiero, P., Kaminsky, G.M., and Gelfenbaum G.R., 2019, Beach topography and nearshore bathymetry of the Columbia River littoral cell, Washington and Oregon (ver. 3.0, December 2021): U.S. Geological Survey data release, https://doi.org/10.5066/P9W15JX8.
Online_Linkage: https://doi.org/10.5066/P9W15JX8
Cross_Reference:
Citation_Information:
Originator: Federal Geographic Data Committee
Publication_Date: 1998
Title:
Geospatial Positioning Accuracy Standards Part 3: National Standard for Spatial Data Accuracy
Other_Citation_Details: FGDC-STD-007.3-1998
Online_Linkage:
https://www.fgdc.gov/standards/projects/FGDC-standards-projects/accuracy/part3/chapter3
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The attribute values of these DSMs represent elevation, the accuracy of which is discussed in the Vertical Positional Accuracy Report section of the metadata.
Logical_Consistency_Report:
Accuracy tests were performed on these data to estimate positional accuracy. These tests are discussed in the Positional Accuracy section of the metadata. Some areas of noise resulting from waves and water in the surf zone, standing water, or areas of uniform color and texture were manually masked and removed from the final product. Some noise may remain near boundaries of the domain or near water and should be treated with caution.
Completeness_Report:
Dataset is considered complete for the information presented, as described in the abstract. For the purpose of creating the final DSMs, areas of data artifacts caused by waves and water in the surf zone, and ponded water on the beach, or areas of uniform color and texture were removed from the data by filtering the dense point cloud used to create the DSM using only points with "point confidence" > 3. Additional areas of noise were removed through visual analysis and clipping in a GIS, however not all areas of noise and artifacts were removed. Users are advised to read the rest of the metadata record carefully for additional details.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
For each DSM, horizontal accuracy was estimated by comparing ground control point (GCP) positions measured with RTK GPS measurements to their SfM-estimated positions. 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. To evaluate the horizontal positional accuracy of the final SfM alignments, each GCPs was disabled one at a time using a python script to create a 'temporary check point'. With the 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. Following the Federal Geographic Data Committee (FGDC) National Standard for Spatial Data Accuracy guidelines, we use the RMSE to calculate the positional horizontal accuracy at the 95 percent confidence level. To account for additional uncertainty in the GPS-measured positions of the GCPs (0.030 meters) we include this as an additional error term through summation in quadrature to arrive at an estimate of total positional horizontal accuracy. The error statistics and horizontal accuracy estimates for each of the DSMs are below:
- FortStevens_2021-07-22_DSM_10cm.tif: Horizontal RMSE (m): 0.023; Horizontal MAE (m): 0.021; Horizontal accuracy at the 95 percent confidence level (m): 0.040; Total horizontal accuracy estimate at the 95 percent confidence level, including GPS uncertainty (m): 0.050;
- BensonBeach_2021-07-23_DSM_10cm.tif: Horizontal RMSE (m): 0.015; Horizontal MAE (m): 0.013; Horizontal accuracy at the 95 percent confidence level (m): 0.026; Total horizontal accuracy estimate at the 95 percent confidence level, including GPS uncertainty (m): 0.040;
It should be noted that this error estimate is for areas of bare ground 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 with uniform coloration) 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:
For each DSM, vertical accuracy was estimated using two methods to compare the DSM vertical elevations to concurrently collected real-time kinematic (RTK) GPS measurements.
The first method used a comparison of ground control point (GCP) positions measured with PPK GPS measurements to their SfM-estimated positions. 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 DSM. To evaluate the vertical positional accuracy of the final SfM alignments, 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. Following the Federal Geographic Data Committee (FGDC) National Standard for Spatial Data Accuracy guidelines, we use the RMSE to calculate the positional vertical accuracy at the 95 percent confidence level. To account for additional uncertainty in the GPS-measured positions of the GCPs (0.038 meters) we include this as an additional error term through summation in quadrature to arrive at an estimate of total positional vertical accuracy. The error statistics and vertical accuracy estimates for each of the DSMs are below:
- FortStevens_2021-07-22_DSM_10cm.tif: Vertical RMSE (m): 0.065; Vertical MAE (m): 0.043; Mean vertical error (m): -0.001; Vertical accuracy at the 95 percent confidence level (m): 0.127; Total vertical accuracy estimate at the 95 percent confidence level, including GPS uncertainty (m): 0.133;
- BensonBeach_2021-07-23_DSM_10cm.tif: Vertical RMSE (m): 0.056; Vertical MAE (m): 0.039; Mean vertical error (m): -0.002; Vertical accuracy at the 95 percent confidence level (m): 0.110; Total vertical accuracy estimate at the 95 percent confidence level, including GPS uncertainty (m): 0.116;
It should be noted that this error estimate is for areas of bare ground or low vegetation where GCPs were placed.
A second method was used to attempt to quantify the vertical errors in areas away from the GCPs, through comparison with concurrently collected backpack and ATV-mounted RTK GPS data (Stevens and others, 2021). The DSM elevations were compared to these measurements using bilinear interpolation at each GPS point to calculate the root-mean-square error (RMSE), mean-absolute error (MAE), and mean vertical error (bias). The error statistics and vertical accuracy estimates relative to the RTK-measured backpack and ATV RTK-GPS data for each of the DSMs are below:
- FortStevens_2021-07-22_DSM_10cm.tif: Number of measurements: 16,967; Vertical RMSE relative to concurrently collected RTK GPS measurements (m): 0.074; Vertical MAE relative to concurrently collected RTK GPS measurements (m): 0.043; Mean vertical error (bias) relative to concurrently collected RTK GPS measurements (m): -0.027 (DSM higher than RTK GPS measurements);
- BensonBeach_2021-07-23_DSM_10cm.tif: Number of measurements: 21,822; Vertical RMSE relative to concurrently collected RTK GPS measurements (m): 0.068; Vertical MAE relative to concurrently collected RTK GPS measurements (m): 0.052; Mean vertical error (bias) relative to concurrently collected RTK GPS measurements (m): -0.045 (DSM higher than RTK GPS measurements);
These slightly higher RMSE are due in part to the less precise nature of the backpack and ATV-mounted GPS measurements used as check points for this process. However, these comparisons do provide a more conservative, spatially distributed estimate of the true accuracy of the elevation models than the GCP check point method. We present both estimates here to provide the end-user with a more complete understanding of the accuracy of the final data products. It should be noted that additional sources of error such as poor image-to-image point matching due to water, vegetation or uniform substrate texture (such as sand with uniform coloration) resulting in poor surface reconstruction may cause localized errors in some portions of the DSMs 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. During acquisition the UAS was flown on pre-programmed autonomous flight lines at an approximate altitude of 120 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 3.2 centimeters per pixel. The flight lines were spaced to provide approximately 66 percent overlap between images from adjacent lines. 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 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: 202107
Process_Step:
Process_Description:
Ground control was established using ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary "X" marks placed with chalk on the ground surface throughout the survey area. The GCP positions were measured using post-processed kinematic (PPK) GPS, using corrections from GPS base stations located near the survey area. For each GCP measurement the GPS receiver was placed on a fixed-height tripod and set to occupy the GCP for a minimum occupation time of one minute. Post-processing was conducted using the Trimble Business Center software package.
Process_Date: 202107
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)
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 calls the exiftool utility. 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 the Fort Stevens survey on 2021-07-22 the image time stamps from camera "RB" were adjusted by +00:00:04 (4 seconds) to synchronize with corrected UTC time. For the Benson Beach survey on 2021-07-23 the image time stamps from camera "RA" were adjusted by -00:00:01 (-1 second) to synchronize with corrected UTC time; the image time stamps from camera "RB" were adjusted by +00:00:04 (4 seconds) 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:4979), with elevation in meters relative to the WGS84 ellipsoid.
Additional information was added to the EXIF using the command-line 'exiftool' software. For the Fort Stevens imagery the following command was used: exiftool ^ -P ^ -IPTC:Credit="U.S. Geological Survey" ^ -IPTC:Contact="pcmsc_data@usgs.gov" ^ -EXIF:Copyright="Public Domain" ^ -XMP: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." ^ -EXIF:ImageDescription="Aerial image of the beach at Fort Stevens State Park, Oregon, USA, from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-632-FA), conducted under Oregon Parks and Recreation Department Scientific Research Permit #235" ^ -XMP:Event="Unoccupied Aircraft System survey of the beach at Fort Stevens State Park, Oregon, USA, during USGS field activity 2021-632-FA, conducted under Oregon Parks and Recreation Department Scientific Research Permit #235" ^ -EXIF:GPSAreaInformation="Position from UAS onboard autonomous single-frequency GNSS." ^ -EXIF:GPSMapDatum="EPSG:4979 (WGS 84)" ^ -EXIF:Artist="U.S. Geological Survey, Pacific Coastal and Marine Science Center" ^ -IPTC:CopyrightNotice="Public Domain. Please credit U.S. Geological Survey." ^ -IPTC:Caption-Abstract="Aerial image of the beach at Fort Stevens State Park, Oregon, USA, from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA conducted under Oregon Parks and Recreation Department Scientific Research Permit #235" ^ -sep ", " ^ -keywords="Columbia River, Fort Stevens State Park, South Jetty, Oregon, 2021-632-FA, Unoccupied Aircraft System, UAS, drone, aerial imagery, U.S. Geological Survey, USGS, Pacific Coastal and Marine Science Center" ^ -comment="Low-altitude aerial image from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA conducted under Oregon Parks and Recreation Department Scientific Research Permit #235" ^ -Orientation= ^ -XMP:AttributionURL="https://doi.org/10.5066/P9BVTVAW" ^ -OffsetTime*=+00:00 ^ -ext DNG ^ -ext JPG
For the Benson Beach imagery the following command was used: exiftool ^ -P ^ -IPTC:Credit="U.S. Geological Survey" ^ -IPTC:Contact="pcmsc_data@usgs.gov" ^ -EXIF:Copyright="Public Domain" ^ -XMP: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." ^ -EXIF:ImageDescription="Aerial image of Benson Beach at Cape Disappointment State Park, Washington, USA, from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-632-FA), conducted under Washington State Parks and Recreation Commission Scientific Research Permit 170603" ^ -XMP:Event="Unoccupied Aircraft System survey of Benson Beach at Cape Disappointment State Park, Washington, USA, during USGS field activity 2021-632-FA, conducted under Washington State Parks and Recreation Commission Scientific Research Permit 170603" ^ -EXIF:GPSAreaInformation="Position from UAS onboard autonomous single-frequency GNSS." ^ -EXIF:GPSMapDatum="EPSG:4979 (WGS 84)" ^ -EXIF:Artist="U.S. Geological Survey, Pacific Coastal and Marine Science Center" ^ -IPTC:CopyrightNotice="Public Domain. Please credit U.S. Geological Survey." ^ -IPTC:Caption-Abstract="Aerial image of Benson Beach at Cape Disappointment State Park, Washington, USA, from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA conducted under Washington State Parks and Recreation Commission Scientific Research Permit 170603" ^ -sep ", " ^ -keywords="Columbia River, Cape Disappointment State Park, North Jetty, Washington, 2021-632-FA, Unoccupied Aircraft System, UAS, drone, aerial imagery, U.S. Geological Survey, USGS, Pacific Coastal and Marine Science Center" ^ -comment="Low-altitude aerial image from USGS Unoccupied Aircraft System (UAS) survey 2021-632-FA conducted under Washington State Parks and Recreation Commission Scientific Research Permit 170603" ^ -Orientation= ^ -XMP:AttributionURL="https://doi.org/10.5066/P9BVTVAW" ^ -OffsetTime*=+00:00 ^ -ext DNG ^ -ext JPG
Additional metadata tags were populated for all of the imagery metadata using the following command: exiftool ^ -P ^ "-XMP-photoshop:Credit<IPTC:Credit" ^ "-XMP-iptcCore:CreatorWorkEmail<IPTC:Contact" ^ "-XMP-dc:Rights<EXIF:Copyright" ^ "-XMP-dc:Description<EXIF:ImageDescription" ^ "-XMP-exif:all<GPS:all" ^ "-XMP-exif:GPSLatitude<Composite:GPSLatitude" ^ "-XMP-exif:GPSLongitude<Composite:GPSLongitude" ^ "-XMP-exif:GPSDateTime<Composite:GPSDateTime" ^ "-XMP-photoshop:DateCreated<EXIF:DateTimeOriginal" ^ "-XMP-xmp:ModifyDate<EXIF:ModifyDate" ^ "-XMP-dc:Creator<EXIF:Artist" ^ "-XMP-tiff:Make<EXIF:Make" ^ "-XMP-tiff:Model<EXIF:Model" ^ -overwrite_original ^ -ext JPG ^ -ext DNG
Process_Date: 2022
Process_Step:
Process_Description:
Structure-from-motion (SfM) processing techniques were used to create point clouds, DSMs, and orthomosaic images in the Agisoft Photoscan/Metashape software package using the following workflow: 1. Initial image alignment was performed using an automated python script (Logan and others, 2022), with the following parameters: Accuracy: 'high' Pair selection: 'reference', 'generic' Key point limit: 60,000 Tie point limit: 0 (unlimited) 2. Ground control point (GCP) positions were imported, and markers were manually identified and placed in the images. 3. After initial alignment and GCP placement, all initial camera positions (from the UAS onboard single-frequency GPS) were disabled to reduce camera position errors. 4. Sparse point cloud error reduction was performed using the automated python script (Logan and others, 2022), to sequentially apply the Reconstruction Uncertainty and Projection Accuracy gradual selection filters to remove 50percent of the sparse points, followed by camera optimization. This resulted in the following final gradual selection filter values: - For Fort Stevens: Final Reconstruction Uncertainty: 24.2 Final Projection Accuracy: 4.0 Lens calibration parameters for optimization: f, cx, cy, k1, k2, k3, p1, and p2 - For Benson Beach: Final Reconstruction Uncertainty: 20.8 Final Projection Accuracy: 3.3 Lens calibration parameters for optimization: f, cx, cy, k1, k2, k3, p1, and p2 5. Additional sparse point cloud error reduction was performed using the automated python script to iteratively apply the Reprojection Error gradual selection filter and camera optimization such that no more than 10percent of the remaining sparse points are deleted at a time. Between each iteration of the filter, camera optimization was performed with the following lens calibration parameters: f, cx, cy, k1, k2, k3, p1, and p2. Once Reprojection Error was reduced below 1 pixel, additional lens calibration parameters (k4, b1, b2, p3, and p4) were included during optimization. This process was repeated until the following final Reprojection Error filter levels were achieved: - For Fort Stevens: Final Reprojection Error: 0.3 Lens calibration parameters for optimization: f, b1, b2, cx, cy, k1, k2, k3, k4, p1, p2, p3 and p4 - For Benson Beach: Final Reprojection Error: 0.4 Lens calibration parameters for optimization: f, b1, b2, cx, cy, k1, k2, k3, k4, p1, p2, p3 and p4 Additional remaining sparse points obviously above or below the true surface were manually deleted after the last error reduction iteration, and a final optimization was performed. 6. Dense point clouds were created using the 'high' accuracy setting, with 'aggressive' depth filtering, and point "confidence" calculated. Points with "confidence" less than 4 were classified as LAS class 7 (Low Point [Noise]). All other points were left with point classification 0 (unclassified). The point clouds were exported to LAZ format in 500 by 500 meter tiles, with point confidence in the extra bytes fields. 7. Preliminary Digital Surface Models (DSM) with native resolutions of 5.93 and 6.02 centimeters per pixel (for Fort Stevens and Benson Beach, respectively) were created using all points in the dense point clouds not classified as class 7 in the preceding step. The DSM were exported to GeoTIFF files with 10-centimeter pixel resolutions. 8. RGB orthomosaics with native resolutions of 2.97 and 3.01 centimeters per pixel (for Fort Stevens and Benson Beach, respectively) were created using the preliminary DSM as the orthorectification surface and exported to GeoTIFF files with 2.5-centimeter pixel resolutions. 9. Generalized exterior clipping boundaries were manually digitized in Agisoft to exclude areas outside of the areas of interest. 10. The RGB orthomosaics were exported to GeoTIFF formats with 2.5-centimeter pixel resolutions, using the digitized polygons as exterior boundaries. 11. The RGB orthomosaics were converted to cloud optimized GeoTIFF formats (using internal JPEG compression with a quality of 90) for compatibility with cloud storage services using the gdal_translate utility in the GDAL software package. 12. The orthomosaics and DSM GeoTIFFs were used as background maps in QGIS to manually delineate clipping polygons to exclude areas of poor surface reconstruction in the DSMs due to standing water, waves in the surf zone, or sand of uniform color. 13. The digitized polygons were used to clip the final DSMs using the gdalwarp utility in the GDAL software package. 14. The gdal_translate utility in the GDAL software package was used to convert the DSMs to cloud optimized GeoTIFF formats with DEFLATE compression, and internal statistics.
Process_Date: 2022
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: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 4602
Lambert_Conformal_Conic:
Standard_Parallel: 47.33333
Standard_Parallel: 45.83333
Longitude_of_Central_Meridian: -120.50000
Latitude_of_Projection_Origin: 45.33333
False_Easting: 500000.0
False_Northing: 0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 0.100
Ordinate_Resolution: 0.100
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983 (EPSG:4269)
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:
Detailed_Description:
Entity_Type:
Entity_Type_Label: GeoTIFF
Entity_Type_Definition: GeoTIFF containing elevation values.
Entity_Type_Definition_Source: Producer defined
Attribute:
Attribute_Label: Band_1
Attribute_Definition: Elevation relative to NAVD88 in units of meters.
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -2.554
Range_Domain_Maximum: 84.383
Overview_Description:
Entity_and_Attribute_Overview:
The dataset consists of a raster which represents elevation values and contains a single attribute. Each cell in the raster corresponds to a location and contains a numeric value indicating the elevation relative to NAVD88 in units of meters.
Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
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 DSMs are available as Cloud Optimized GeoTIFF 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: GeoTIFF
Format_Version_Number: GDAL 3.5.1
Format_Information_Content:
Cloud Optimized GeoTIFF contains a Digital Surface Model (DSM) with single-precision floating-point values compressed using the DEFLATE lossless compression method. No data value is -32767. The transfer size listed reflects the largest size file that may be downloaded. Other files in this data release are smaller.
File_Decompression_Technique: none
Transfer_Size: 746
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
https://www.sciencebase.gov/catalog/file/get/62e470b4d34e749ac04cb783?name=FortStevens_2021-07-22_DSM_10cm.tif
Network_Resource_Name:
https://www.sciencebase.gov/catalog/file/get/62e470b4d34e749ac04cb783?name=BensonBeach_2021-07-23_DSM_10cm.tif
Network_Resource_Name:
https://prod-is-usgs-sb-prod-publish.s3.amazonaws.com/62e470b4d34e749ac04cb783/FortStevens_2021-07-22_DSM_10cm.tif
Network_Resource_Name:
https://prod-is-usgs-sb-prod-publish.s3.amazonaws.com/62e470b4d34e749ac04cb783/BensonBeach_2021-07-23_DSM_10cm.tif
Network_Resource_Name:
https://www.sciencebase.gov/catalog/item/62e470b4d34e749ac04cb783
Network_Resource_Name: https://doi.org/10.5066/P9BVTVAW
Access_Instructions:
Data can be downloaded using the Network_Resource_Name links. The first two links are direct links to download the 10-centimeter DSMs in GeoTIFF format. The second two links are for accessing the DSMs on cloud-based storage and can be used for cloud-based queries or viewing. The fifth link points to a landing page with the DSM, metadata, and a browse image. The sixth link points to the landing page for the entire data release, including links to pages of the various data files.
Fees: None.
Technical_Prerequisites:
These data can be viewed with GIS software or other software capable of displaying geospatial raster data.
Metadata_Reference_Information:
Metadata_Date: 20231107
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
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_P9BVTVAW/FortStevens_BensonBeach_2021-07_DSM_metadata.html>
Generated by mp version 2.9.51 on Fri Nov 17 13:30:50 2023