Andrew C. Ritchie
Jin-Si R. Over
20221011
Digital elevation models (DEMs) of coastal North Carolina, on 2019-10-11, one month Post-Hurricane Dorian
1.0
raster digital data (GeoTIFF)
data release
DOI:10.5066/P9K3TWY7
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P9K3TWY7
Andrew C. Ritchie
Jin-Si R. Over
Christine J. Kranenburg
Jenna A. Brown
Daniel D. Buscombe
Christopher R. Sherwood
Jonathan A. Warrick
Phillipe A. Wernette
2022
Aerial photogrammetry data and products of the North Carolina coast
1.0
digital files
data release
DOI:10.5066/P9K3TWY7
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P9K3TWY7
Digital elevation models (DEMs) were created from aerial imagery collected October 11, 2019, along the North Carolina coast between the Virginia-North Carolina border vicinity and Cape Lookout, North Carolina. These DEMs were created to document ground conditions one-month after Hurricane Dorian, which made landfall on the North Carolina coast on September 6, 2019.
The DEMs help researchers estimate the land surface one-month post-Hurricane Dorian and were created to document inter-annual changes in shoreline position and coastal morphology in response to storm events using aerial imagery collections and a structure from motion (SFM) workflow. These data can be used with geographic information systems or other software to identify topographic and shallow-water bathymetric features.
U.S. Geological (USGS) researchers use the DEMs to assess future coastal vulnerability, nesting habitats for wildlife, and provide data for hurricane impact models. The products span the coast over both highly developed towns and natural areas, including federal lands. This research is part of the USGS Remote Sensing Coastal Change Project.
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=2019-312-CNT
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
The raw imagery and navigation data used to produce the DEMs are available online at https://doi.org/10.5066/P9RRSMOJ. Bounding coordinates for the metadata are derived from the overall flight path and are not necessarily representative of individual DEM product boundaries, which are split up along the coast to have more accessible data-download sizes. See image at https://www.sciencebase.gov/catalog/file/get/617352c1d34ea36449a8838b?name=Product_Boundary_Map.jpg for geographic locations used to create the data subsets. Note that the term DEM is used throughout this data release, but digital surface model (DSM) is also appropriate, as the models include vegetation and other canopy returns.
20191011
Ground condition, data were collected on one day: October 11, 2019.
Not planned
-76.54691663
-75.45895472
36.26709770
34.58252919
ISO 19115 Topic Category
geoscientificInformation
oceans
imageryBaseMapsEarthCover
Data Categories for Marine Planning
Bathymetry and Elevation
Physical Habitats and Geomorphology
Marine Realms Information Bank (MRIB) keywords
remote sensing
fragile ecosystems
beach
barrier island
geographic information systems (GIS)
hurricanes and typhoons
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Pacific Coastal and Marine Science Center
PCMSC
Woods Hole Coastal and Marine Science Center
WHCMSC
Saint Petersburg Coastal and Marine Science Center
SPCMSC
Remote Sensing Coastal Change
Hurricane Dorian
digital surface models
Outer Banks
USGS Thesaurus
structure from motion
remote sensing
geomorphology
geospatial datasets
digital elevation models
earth sciences
geography
coastal processes
hurricanes
USGS Metadata Identifier
USGS:619d357cd34eb622f69526e3
Geographic Names Information System (GNIS)
Atlantic Ocean
Pamlico Sound
State of North Carolina
Commonwealth of Virginia
Cape Lookout
Cape Hatteras
Duck (1025292)
Oregon Inlet
Hatteras Inlet
Ocracoke Inlet
Ophelia Inlet
Beaufort Inlet
Cape Lookout
None
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. These data are not intended for navigational use.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
https://www.sciencebase.gov/catalog/file/get/619d357cd34eb622f69526e3?name=201910_DEM_NC_example.JPG&allowOpen=true
Example segment of an elevation-colored digital elevation model from 2019-10-11.
JPEG
Microsoft Windows 10, Agisoft Metashape Professional version 1.6.5, gdal version 3.1.4., QGIS 3.2.2.
Jin-Si R. Over
Andrew C. Ritchie
Christine J. Kranenburg
Jenna A. Brown
Daniel D. Buscombe
Tommy Noble
Christopher R. Sherwood
Jonathan A. Warrick
Phillipe A. Wernette
2021
Processing coastal imagery with Agisoft Metashape Professional Edition, version 1.6—Structure from motion workflow documentation
Open-File Report
2021-1039
Reston, VA
U.S. Geological Survey
This publication includes the general methodology for processing imagery in Metashape to produce DEMs and ortho products.
https://doi.org/10.3133/ofr20211039
NOAA Office for Coastal Management (OCM Partners)
2019
2018 USACE NCMP Post-Florence Topobathy Lidar DEM: Southeast Coast (VA, NC, SC)
Data Series
57345
Charleston, SC
Office for Coastal Management
This data set was used to qualitatively assess the horizontal and vertical accuracy of the DEM products.
https://www.fisheries.noaa.gov/inport/item/57345
NOAA Office for Coastal Management (OCM Partners)
2019
2019 USACE NCMP DUNEX Topobathy Lidar DEM: East Coast (NC, VA)
Data Series
60197
Charleston, SC
Office for Coastal Management
This data set was used to qualitatively assess the horizontal and vertical accuracy of the DEM products.
https://www.fisheries.noaa.gov/inport/item/60197
Christopher R. Sherwood
Jonathan A. Warrick
Andrew D. Hill
Andrew C. Ritchie
Nathaniel G. Plant
2018
Rapid, remote assessment of Hurricane Matthew impacts using four-dimensional structure-from-motion photogrammetry
Professional Paper
DOI:10.2112/JCOASTRES-D-18-00016.1
Online
Journal of Coastal Research
This publication includes the general methodology described for processing imagery in Metashape in four-dimensions to produce DEMs and ortho products.
https://doi.org/10.2112/JCOASTRES-D-18-00016.1
The source imagery and positional information and metadata that were used to create these photogrammetrically derived digital elevation models are available Kranenburg and others (2022a). Information on the horizontal and vertical accuracies of the source data can be found within the data release metadata. Product vertical accuracy is assessed using published ground control points (Brown and others, 2021). Users are encouraged to do their own accuracy assessment with published lidar or other elevation products to make sure the error estimates and products meet their needs. It should also be noted that accuracy estimates of the products are 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 or moving objects resulting in poor surface reconstruction may cause localized errors in some portions of the DEM to exceed accuracy estimates. Processing imagery in 4D (see processing steps) aims to keep related products precise within the reported accuracies.
There are a total of four DEMs included in this dataset. All data fall into expected elevation ranges except for points near tall buildings, areas of poorer image overlap, and near water (waves, ponds, shorelines), where the data return is often sparse, noisy, and erroneous. The DEM includes returns from the vegetation on land and in the water. Shallow underwater reconstructions have not been corrected for parallax.
The final DEM products are not interpolated and have been cropped to remove the majority, but not all of, the noise and zones of high uncertainty (for example, foreshore, water bodies, areas with poor overlap). Therefore, the DEMs do not cover the same exact extent as the associated orthorectified products in the larger work citation or the original imagery available. GeoTIFFs are cloud-optimized.
Horizontal accuracy is affected by the source data and photogrammetry processing and difficult to quantitatively test. One control point (GCP 34; 0.037-meter xy accuracy) and post-processed kinematic (PPK) camera positions (Kranenburg and others, 2022a; 2022b; 2022c; 2022d) were used to create the final SFM products in 4D. The horizontal (x,y) error of control point GCP 34 after batch co-alignment and error reduction in the Metashape project (see processing steps) was 0.040,-0.048 m. These values do not represent the absolute horizontal georeferencing accuracy of the product but provide a better sense of the overall accuracy. Due to the nature of the in-place GCPs being difficult to distinguish in the orthoimages at their published resolution, no further horizontal accuracy assessment was done with them. A qualitative analysis of gridded first-return lidar data at stable points (OCM Partners, 2018; 2019) supports these base horizontal accuracy estimates.
Only 1 ground control point (GCP 34; 0.043-meter z accuracy; Brown and others, 2021) and the post-processed kinematic (PPK) camera positions (Kranenburg and others, 2022a; 2022b; 2022c; 2022d) were used in the photogrammetry processing to create the final products. The vertical positional accuracy was independently evaluated, outside of Metashape, against 29 of the 34 Brown and others (2021) in-place GCPs within the extent of the Oregon Inlet to Hatteras Inlet DEM. Note that this is separate from the GCP and DEM adjustment detailed in Processing Step 7. These GCP vertical positions were compared to the corrected raster elevations using bilinear interpolation at each GPS point to derive the root-mean-square error (0.083 meters) and MAE (0.063 meters) of the DEM. The “corrected” mean-error (vertical bias) of the GCP measurements relative to DEM elevations was 0.026 meters, meaning the DEM was, on average, reconstructed at a lower elevation than the GPS measurements. The addition of the reported vertical accuracy of the GPS measurements (0.047 meters) in quadrature results in a total vertical accuracy estimate of 0.095 meters for the Oregon Inlet to Hatteras Inlet DEM using this method. Given that the ground control points are only available within the Oregon Inlet to Hatteras Inlet DEM, we assume that all other DEMs in this release (from the border of Virginia to Cape Lookout) have similar vertical non-vegetated accuracies. A qualitative analysis of gridded first return lidar data (OCM Partners, 2018; 2019) supports these accuracy estimates.
Christine J Kranenburg
Andrew C Ritchie
Jenna A Brown
Jin-Si R Over
Christopher R Sherwood
Jonathan A Warrick
Phillipe A Wernette
2022
Aerial imagery of the North Carolina coast: 2019-10-11
JPEG and TXT dataset
St. Petersburg Coastal and Marine Science Center
U.S. Geological Survey
https://doi.org/10.5066/P9RRSMOJ
Digital
20191011
ground condition
Aerial Imagery
The data in this release are used to make the 2019-10-11 SFM products.
Christine J Kranenburg
Andrew C Ritchie
Jenna A Brown
Jin-Si R Over
Christopher R Sherwood
Jonathan A Warrick
Phillipe A Wernette
2022
Aerial imagery of the North Carolina coast: 2019-11-26
JPEG and TXT dataset
St. Petersburg Coastal and Marine Science Center
U.S. Geological Survey
https://doi.org/10.5066/P99TL46N
Digital
20191126
ground condition
Aerial Imagery 4D dataset 1
The data in this release are used in the 4D alignment Metashape SFM Batch2a process.
Christine J Kranenburg
Andrew C Ritchie
Jenna A Brown
Jin-Si R Over
Christopher R Sherwood
Jonathan A Warrick
Phillipe A Wernette
2022
Aerial imagery of the North Carolina coast: 2020-02-08 to 2020-02-09
JPEG and TXT dataset
St. Petersburg Coastal and Marine Science Center
U.S. Geological Survey
https://doi.org/10.5066/P9ISFCVN
Digital
20200208
20200209
ground condition
Aerial Imagery 4D dataset 2
The data in this release are used in the 4D alignment Metashape SFM Batch2a process.
Christine J Kranenburg
Andrew C Ritchie
Jenna A Brown
Jin-Si R Over
Christopher R Sherwood
Jonathan A Warrick
Phillipe A Wernette
2022
Aerial imagery of the North Carolina coast: 2020-05-08 to 2020-05-09
JPEG and TXT dataset
St. Petersburg Coastal and Marine Science Center
U.S. Geological Survey
https://doi.org/10.5066/P9OCDOYZ
Digital
20200508
20200509
ground condition
Aerial Imagery 4D dataset 3
The data in this release are used in the 4D alignment Metashape SFM Batch2a process.
Jenna A. Brown
Christopher R. Sherwood
Marinna Martini
Christine J. Kranenburg
Jin-Si R. Over
2021
Ground Control Point Data from the Outer Banks, North Carolina, post-Hurricane Dorian, October 2019
1.0
tabular digital data
https://doi.org/10.5066/P9DVZC23
Digital and/or Hardcopy
20190924
20190925
ground condition
Ground Control Points
The Ground Control Points are used in the SFM process and to assess horizontal and vertical positional accuracy.
On a workstation (AMD Threadripper 3960X /AsRock TRX40 Creator motherboard/256GB 3000MHz RAM) using Win10x64, aerial imagery and associated positional data (Kranenburg and others 2022a; 2022b; 2022c; 2022d) and a single ground control point (Brown and others, 2021) were brought into an Agisoft Metashape Pro (v. 1.6.5) project to align in a 4D manner (see Sherwood and others, 2019). Only one ground control point, GCP 34, was used as a control point to help 'lock' in the camera positions, whereas the rest of the points were used as independent vertical check points (that is, they were not placed in Metashape). See Kranenburg and others (2022a), for Metashape Reference Settings inputs. The additional imagery improves the horizontal and vertical accuracy, but similar products can be reproduced without them. The following steps were performed on the Metashape project in the geographic coordinate system NAD83(2011) in ellipsoid height following the general guidance of Over and others (2021):
1. Separate camera models and camera groups were created for each flight date aligned in 4D. Note that multiple imagery datasets are used in the overall processing effort to produce the end individual survey products that this metadata file covers.
2. Imagery (with positions) are aligned in 4D to create a point cloud using a 'High' alignment setting, keypoint limit of 70,000, tiepoint limit of 0, generic preselection selected, and reference preselection via source selected. The tiepoint accuracy was set to 1 pixel.
3. The resultant point cloud was filtered using one iteration of the 'Reconstruction uncertainty' filter at a level of 10, one iteration of the 'Projection accuracy' filter at a level of 3, and two iterations of the 'Reprojection accuracy' filer at a level of 0.3 (in the second iteration the 'fit additional corrections' option was turned on). With each filter, iteration points are selected, deleted, and then the camera model is optimized to refine the focal length, cx, cy, k1, k2, k3, p1, and p2 camera model coefficients.
4. Natural breaks in the final alignment product were identified based on bodies of water or the extreme northern and southern ends of a flight (see Product_Boundary_Map.jpg at https://doi.org/10.5066/P9K3TWY7). The breaks and dates of imagery in the 4D process are used for ease and speed of processing. The boundaries used for the one-month post-Hurricane Dorian dataset are the Virginia-North Carolina border vicinity to Oregon Inlet, Oregon Inlet to Hatteras Inlet, Hatteras Inlet to Ocracoke Inlet, Ocracoke Inlet to Cape Lookout.
For each region, sub-chunks were created for each mission (one or two flight-days, usually adjacent) by iteratively copying the original 4D chunk and removing all camera groups not part of a single mission. Note that this particular metadata file only covers the one-month post-Hurricane Dorian dataset collected on 2019-10-11.
Processing took place starting in June 2021 and into February 2022, the latest processing in YYYYMM is given in the Process Date.
Aerial Imagery
Ground Control Points
Aerial Imagery 4D dataset 1
Aerial Imagery 4D dataset 2
Aerial Imagery 4D dataset 3
202202
From the previous process step, each 'chunk' is processed as follows to create the final DEM products for each flight date:
1. Targeted imagery sets in the aligned chunk are copied from the workstation to a new Agisoft Metashape Pro. project on the U.S Geological Survey Tallgrass high-performance computing network for processing on CPU and GPU nodes (https://www.usgs.gov/core-science-systems/sas/arc/machine-access).
2. If multiple flight dates were flown for this chunk, imagery from one date is targeted, and the rest are disabled (this is then switched for each flight date in the chunk after the final step and steps 3-6 are repeated).
3. A high quality dense point cloud is generated for the chunk with 'mild' filtering and the options to calculate point color and point confidence selected.
4. Dense point cloud is filtered using the 'Filter by Confidence' tool using the range 0-2, these points selected at this range are classified as low noise.
5. A DEM is built from the dense point cloud with interpolation disabled and without the points classified as low noise.
6. DEM is exported in NAD83(2011) UTM Zone 18N and NAVD88(m) with 1-m cell size and region boundaries rounded to the nearest 10 m interval. West and south bounds are rounded up and east and north bounds are rounded down.
7. In order to minimize elevation differences between flights in the 4D reconstruction, all DEMs were then adjusted to a common datum by adding the median signed difference between GCPs (Brown and others, 2021) and the Oregon Inlet to Hatteras Inlet DEM elevations (GCP - DEM) produced by each survey. That is, for DEMs from 2019-10-11 to 2020-05-09, differences were calculated for all GCPs and all Oregon Inlet to Hatteras Inlet DEMs and then these values were ranked, and the middle value was used (or the middle two values were averaged, for an even number of differences) to adjust each DEM in the chunk, not just the Oregon Inlet to Hatteras Inlet DEM. The median value for this 4D reconstruction was -0.03402.
8. Each adjusted DEM was then masked by a human-edited shapefile in QGIS (v. 3.2.2.) to remove high uncertainty regions. Note that the shapefiles are used as part of the workflow to produce the final product and are not provided, if this extent or shapefile needs to be used by someone else it can be recreated in a GIS setting by extracting the outline(s) of the provided raster(s), for example the raster to vector tool in QGIS. Uncertainty was visualized using a hillshade of the DEM with an elevation factor of 5 and an additional raster that highlights areas with a high standard deviation away from the adjusted DEM elevation values. The shapefiles were edited by either S. Bosse, J. Over, E. Lyons, or J. Favela.
9. Final clipped DEMs for the one-month post-Hurricane Dorian dataset are turned into cloud-optimized GeoTIFFs (COG) using gdal_translate with the following command:for %i in (.\*.tif) do gdal_translate %i .\cog\%~ni_cog.tif -of COG -stats -co BLOCKSIZE=256 -co COMPRESS=DEFLATE -co PREDICTOR=YES -co NUM_THREADS=ALL_CPUS -co BIGTIFF=YES (v. 3.1.4 accessed October 20, 2020 https://gdal.org/), where i is the name of each geoTIFF section.
202204
Correction made to network resource link to remove extra space. (scochran@usgs.gov)
20230509
Raster
Pixel
Universal Transverse Mercator
18
0.999600
-69.000000
0.000000
500000.000000
0.000000
row and column
1
1
meters
NAD83_National_Spatial_Reference_System_2011
Geodetic Reference System 80
6378137.000000
298.257222
North American Vertical Datum of 1988
0.001
meters
Explicit elevation coordinate included with horizontal coordinates
20191011_DEM_VA_to_Oregon_Inlet_NAD83_2011_UTM18N_NAVD88_1m_cog.tif
A raster dataset (Cloud-optimized GeoTIFF format) with encoded elevation values of the North Carolina coast from the vicinity of the Virginia State border to Oregon Inlet on October 11, 2019. Pixel resolution is 1-meter.
U.S. Geological Survey
Value
Surface elevation orthometric height (m) in NAVD88 using Geoid 2018
U.S. Geological Survey
-3.4028234663852886e+38
No data
Producer-defined
-7.899
48.954
meters
20191011_DEM_Oregon_Inlet_to_Hatteras_Inlet_NAD83_2011_UTM18N_NAVD88_1m_cog.tif
A raster dataset (Cloud-optimized GeoTIFF format) with encoded elevation values of the North Carolina coast from Oregon Inlet to Hatteras Inlet on October 11, 2019. Pixel resolution is 1-meter.
U.S. Geological Survey
Value
Surface elevation orthometric height (m) in NAVD88 using Geoid 2018
U.S. Geological Survey
-3.4028234663852886e+38
No data
Producer-defined
-17.907
42.871
meters
20191011_DEM_Hatteras_Inlet_to_Ocracoke_Inlet_NAD83_2011_UTM18N_NAVD88_1m_cog.tif
A raster dataset (Cloud-optimized GeoTIFF format) with encoded elevation values of the North Carolina coast from Hatteras Inlet to Ocracoke Inlet on October 11, 2019. Pixel resolution is 1-meter.
U.S. Geological Survey
Value
Surface elevation orthometric height (m) in NAVD88 using Geoid 2018
U.S. Geological Survey
-3.4028234663852886e+38
No data
Producer-defined
-1.975
26.775
meters
20191011_DEM_Ocracoke_Inlet_to_Cape_Lookout_NAD83_2011_UTM18N_NAVD88_1m_cog.tif
A raster dataset (Cloud-optimized GeoTIFF format) with encoded elevation values of the North Carolina coast from Ocracoke Inlet to Cape Lookout on October 11, 2019. Pixel resolution is 1-meter.
U.S. Geological Survey
Value
Surface elevation orthometric height (m) in NAVD88 using Geoid 2018
U.S. Geological Survey
-3.4028234663852886e+38
No data
Producer-defined
-7.541
50.763
meters
Pixels represent elevation in meters relative to NAVD88 (Geoid 18). There are four DEM 32-bit floating point cloud-optimized GeoTIFFs. The filename for each DEM is formatted as "date_product_location_to_location_CRS_resolution_cog.tif", where date is the date the images were collected (in YYYYMMDD format), product is Digital Elevation Model (DEM), location_to_location is the specific geographic location in North Carolina of the northern extent to the southern extent, CRS is the horizontal and vertical coordinate reference system used, resolution is the horizontal pixel resolution of the grid, and 'cog' denotes the product is a cloud-optimized GeoTIFF. The horizontal and vertical CRS is NAD83(2011) UTM Zone 18N and NAVD88 for all DEMs.
USGS
U.S. Geological Survey - Sciencebase
mailing address
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
United States
1-888-275-8747
sciencebase@usgs.gov
The four DEM deflate-compressed cloud-optimized GeoTIFFS (COGs) are available in 1-m resolution and represent the coast of North Carolina one-month after Hurricane Dorian on October 11, 2019.
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. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
GeoTIFF
Cloud-optimized 32-bit floating point 1-m GeoTIFFs deflate compressed.
none
1100
https://www.sciencebase.gov/catalog/file/get/619d357cd34eb622f69526e3
https://www.sciencebase.gov/catalog/item/619d357cd34eb622f69526e3
https://doi.org/10.5066/P9K3TWY7
Data can be downloaded using the Network_Resource_Name links. The first link will begin a direct download of a zip file containing all the datasets and metadata (the transfer size in MB). The second link is to the page where you can download data files individually. The third link points to the landing page for the entire data release.
none
20230509
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998