Jin-Si R. Over
20230328
High resolution structure from motion digital surface models representing three sites on North Core Banks, NC in October 2022
1.0
raster digital data
data release
DOI:10.5066/P99IV3FC
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Hazards and Resources Program
https://doi.org/10.5066/P99IV3FC
https://www.sciencebase.gov/catalog/item/63ae0f3fd34e92aad3ca5bcd
Jin-Si R. Over
Christopher R. Sherwood
Jennifer M. Cramer
Alexandra D. Evans
Sara L. Zeigler
2023
Topographic, bathymetric, multispectral, vegetation, sediment, and supporting GPS data collected on North Core Banks, Cape Lookout National Seashore, North Carolina in October 2022, U.S. Geological Survey Field Activity 2022-034-FA
1.0
digital data
data release
DOI:10.5066/P99IV3FC
Reston, VA
U.S. Geological Survey
Suggested citation: Over, J.R., Sherwood, C.R., Cramer, J.M., Evans, A.D., and Zeigler, S.L, 2023, Topographic, bathymetric, multispectral, vegetation, sediment, and supporting GPS data collected on North Core Banks, Cape Lookout National Seashore, NC in October 2022, U.S. Geological Survey Field Activity 2022-034-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P99IV3FC.
https://doi.org/10.5066/P99IV3FC
https://www.sciencebase.gov/catalog/item/63ade364d34e92aad3ca5b2c
These data map in high detail surficial cross-sections of North Core Banks, a barrier island in Cape Lookout National Seashore, NC, in October 2022. U.S. Geological Survey field efforts are part of an interagency agreement with the National Park Service to monitor the recovery of the island from Hurricanes Florence (2018) and Dorian (2019). Three sites of outwash, overwash, and pond formation were targeted for extensive vegetation ground-truthing, sediment samples, bathymetric mapping with a remote-controlled surface vehicle, and uncrewed aerial systems (UAS) flights to collect multispectral imagery. Five semi-permanent ground control points were also installed and surveyed to act as control for additional aerial imagery collected via plane. UAS imagery were processed in Agisoft Metashape (v. 1.8.1) with surveyed temporary ground control points to produce calibrated multispectral (red, blue, green, red edge, near infrared, and panchromatic) orthoimages and digital surface models.
U.S. Geological Survey (USGS) researchers use the digital surface models (DSMs) to assess future coastal vulnerability, nesting habitats for wildlife, and provide data for hurricane impact models. The products span three sites on North Core Banks that can be compared to previous aerial survey products.
For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2022034FA. Bounding coordinates represent the maximum extent of all the DSMs, not the individual sites.
20221019
20221020
Ground condition; multiple survey days.
Not planned
-76.27257445
-76.22241438
34.92739173
34.88789705
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Woods Hole Coastal and Marine Science Center
WHCMSC
Agisoft Metashape
digital surface model
Remote Sensing Coastal Change
Hurricane Florence
Hurricane Dorian
National Seashore
USGS Thesaurus
remote sensing
digital elevation models
datasets
structure from motion
Marine Realms Information Bank (MRIB) keywords
topographic mapping
Data Categories for Marine Planning
Physical Habitats and Geomorphology
ISO 19115 Topic Category
geoscientificInformation
elevation
USGS Metadata Identifier
USGS:63ae0f3fd34e92aad3ca5bcd
Geographic Names Information System (GNIS)
Atlantic Ocean
State of North Carolina
Cape Lookout
North Core Banks
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.
Jin-Si R. Over
U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center
Geographer
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
508-548-8700 x2297
jover@usgs.gov
https://www.sciencebase.gov/catalog/file/get/63ae0f3fd34e92aad3ca5bcd?name=2022034FA_NCB_DSM_browse.JPG&allowOpen=true
Elevation-colored image of topography data collected from New Pond 1, North Core Banks.
JPEG
Metashape 1.8.1
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
data release
DOI:10.5066/P9K3TWY7
Reston, VA
U.S. Geological Survey
This data release contains data products that cover North Core Banks and can be used in data quality assessments and comparative elevation studies.
https://doi.org/10.5066/P9K3TWY7
Jin-Si R. Over
Andrew C. Ritchie
Christine J. Kranenburg
Jenna A. Brown
Daniel D. Buscombe
Tom 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 digital surface models and ortho products.
https://doi.org/10.3133/ofr20211039
DSMs were produced using a 4D structure-from-motion (SfM) processing workflow (see Over and others (2021) for more details) that aligned the Ricoh and Altum-PT panchromatic band images together to produce a more stable product, DSMs produced in 3D from the Ricoh and Altum-PT images separately had very high errors on the edges. Ground control points (GCPs) were used to constrain the digital surface models (DSMs) – see larger work citation for details on accuracies of these data. Final product vertical accuracy was assessed using RTK GPS points taken within the survey areas (point data are available in the larger work citation). It should also be noted that accuracy estimates of the products are for areas of bare ground or low vegetation where GCPs were placed and GPS points taken. Additional sources of error, such as poor image-to-image point matching due to vegetation or uniform substrate texture or moving objects, may cause localized errors in some portions of the DSM to exceed accuracy estimates.
There are a total of three DSMs included in this dataset distinguished by the names of the sites surveyed: New Pond 0 (NP0), New Pond 1 (NP1), and New Pond 3 (NP3). New Pond 2 was abandoned as a site due to time constraints. All data fall into expected elevation ranges of a low-lying barrier island except for points near the edges and near water (waves, ponds, shorelines), where the data return is often sparse, noisy, and erroneous. The DSM includes returns from the vegetation on land and in the water. Shallow underwater reconstructions have not been corrected for parallax.
The structure from motion dense point clouds that the DSMs are built from were hand edited to remove the majority of, but not all, reconstructed points with low confidence. The topographic surface is also not interpolated to fill holes. The DSMs do not cover the same exact extent as the associated orthorectified products in the larger work citation or the original imagery available, mostly due to the removal or poor reconstruction of water surfaces. GeoTIFFs are cloud-optimized.
Horizontal accuracy is affected by the source data and photogrammetry processing and difficult to quantitatively test, especially as this is the highest resolution dataset currently available in a very dynamic environment with no surveyed stable features. A cursory qualitative analysis of the UAS DSMs compared against published DSMs with overlapping extent (Ritchie and others, 2022) indicates the products align well as can be discerned between a 5 cm and 1 meter product. The horizontal root mean square error (RMSE) of the GCPs as reported from the Metashape projects for each site are given here. NP0 GCP (n=5) RMSE was xy: 0.013, 0.018 (m), NP1 GCP (n=3) RMSE was xy: 0.028, 0.032 (m), and NP3 GCP (n=5) RMSE was xy: 0.011, 0.004 (m). These values do not represent the absolute horizontal georeferencing accuracy of the product but provide a better sense of the overall processing accuracy.
The vertical RMSE of the GCPs as reported from the Metashape projects for each site are given here. NP0 GCP (n=5) RMSE was 0.017 m, NP0 GCP (n=3) RMSE was 0.005 m, and NP0 GCP (n=5) RMSE was 0.018 m. The vertical positional accuracy was independently evaluated, outside of Metashape, against GPS points within the extent of each site. These GPS points were compared to the raster elevations at each site; at NP0 the GPS points (n=18) RMSE was 0.054 m, at NP1 the GPS points (n=12) RMSE was 0.092 m, and at NP3 the GPS points (n=68) RMSE was 0.032 m.
The DSMs were created in Agisoft Metashape v. 1.8.1 using the following general steps (see Over and others, 2021 for a more detailed methodology explanation):
1. For each site (NP0, NP1, and NP3) a new project was created and Ricoh imagery and Altum-PT panchromatic band imagery (located in larger work citation) were imported.
2. Photos were aligned at a low accuracy and then GCPs were automatically detected in the point cloud. GCP positions (2022034FA_NCB_GCPs.csv located in the larger work citation) were added to the project in the reference systems NAD83(2011)/UTM Zone 18N and NAVD88 (geoid 18). Accuracies for the GCPs were set to 0.05 m and the camera positions for the panchromatic band images were turned off. The photos were then re-aligned with high accuracy (the pixels were not subsampled but processing speed decreased) using a keypoint limit of 60,000 and unlimited tie points.
3. The alignment process matched pixels between images and created point clouds and put the imagery into a relative spatial context using the GCPs. The resultant point clouds were filtered using one iteration of the 'Reconstruction uncertainty' filter at a level of 12, one iteration of the 'Projection accuracy' filter at a level of 3, and three iterations of the 'Reprojection accuracy' filter to get to a level of 0.3. With each filter, iteration points were selected, deleted, and then the camera model was optimized to refine the focal length, cx, cy, k1, k2, k3, p1, and p2 camera model coefficients.
4. At this point, the Ricoh images were disabled so only the Altum-PT images were used to create a dense point cloud using the high-quality setting (images were not subsampled) and a low-frequency filtering algorithm. Note, this process was reversed so only Ricoh imagery was enabled, but the final product from that iteration was inferior when compared to the GPS points (see accuracy report). The dense point cloud was then edited by visual inspection and Metashape’s confidence filter to remove points with a low confidence near the edges and near water bodies.
4. The DSM products were exported at 5 cm in NAD83(2011)/UTM Zone 18N and NAVD88 (m). Region boundaries were rounded to the nearest 5 m interval. West and south bounds were rounded up and east and north bounds were rounded down.
202212
The DSMs were then turned into cloud-optimized GeoTIFFz (COG) using gdal_translate with the following command: for %i in (.\*.tif) do gdal_translate %i .\%~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.
20221216
Jin-Si R. Over
U.S Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center
Geographer
mailing and physical address
384 Woods Hole Rd
Woods Hole
MA
02543
508-548-8700 x2297
jover@usgs.gov
Raster
Pixel
Universal Transverse Mercator
18
0.999600
-75.000000
0.000000
500000.000000
0.000000
row and column
0.001
0.001
meters
North American Datum of 1983 (National Spatial Reference System 2011)
GRS_1980
6378137.000000
298.257222101
North American Vertical Datum of 1988, using geoid 18
0.0001
meters
Explicit elevation coordinate included with horizontal coordinates
2022034FA_NCB_NP0_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif
A raster dataset with encoded elevation values of New Pond 0 built from MicaSense Altum-PT panchromatic band images. Pixel resolution is 5 cm.
producer defined
Value
Surface elevation orthometric height NAVD88 (m) using Geoid 18 in NAD83(2011)/UTM Zone 18N.
producer defined
-999
No data
Producer-defined
-1.1205
4.6258
meters
2022034FA_NCB_NP1_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif
A raster dataset with encoded elevation values of New Pond 1 built from MicaSense Altum-PT panchromatic band images. Pixel resolution is 5 cm.
producer defined
Value
Surface elevation orthometric height NAVD88 (m) using Geoid 18 in NAD83(2011)/UTM Zone 18N.
producer defined
-999
No data
Producer-defined
-2.1147
4.8020
meters
2022034FA_NCB_NP3_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif
A raster dataset with encoded elevation values of New Pond 3 built from MicaSense Altum-PT panchromatic band images. Pixel resolution is 5 cm.
producer defined
Value
Surface elevation orthometric height NAVD88 (m) using Geoid 18 in NAD83(2011)/UTM Zone 18N.
producer defined
-999
No data
Producer-defined
-0.9543
6.5958
meters
Pixels represent elevation in meters relative to NAVD88 (geoid 18). The filename is formatted as "2022034FA_NCB_NP#_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif", where 2022034FA is the USGS Field activity ID, NCB_NP# is the location – North Core Banks (NCB) and New Pond (NP) 0, 1, or 3, Altum-PT is the sensor, DSM is Digital Surface Model, 5cm indicates the resolution of the grid, UTM18N_NAVD88 indicates the coordinate reference systems, and cog is cloud optimized GeoTIFF. Pixel row and column size of 2022034FA_NCB_NP0_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif is 9500 x 9200, 2022034FA_NCB_NP1_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif is 12300 x 12100, 2022034FA_NCB_NP3_Altum-PT_DSM_5cm_UTM18N_NAVD88_cog.tif is 11800 x 11700.
USGS Field Activity 2022-034-FA
Jin-Si R. Over
U.S. Geological Survey, Northeast Region, , Woods Hole Coastal and Marine Science Center
Geographer
mailing and physical
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
508-548-8700 x2297
jover@usgs.gov
GeoTIFF files are 32-bit floating point digital surface models.
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
GeoTIFF
1.0.0
32-bit floating point GeoTIFF format
Encoded surface elevations.
407
https://www.sciencebase.gov/catalog/file/get/63ae0f3fd34e92aad3ca5bcd
https://www.sciencebase.gov/catalog/item/63ae0f3fd34e92aad3ca5bcd
https://doi.org/10.5066/P99IV3FC
The first link in the list above is to directly download the GeoTIFFs as a zip file, the second to the data page to download files individually, and the third link is to the publication landing page.
None.
20230328
Jin-Si R. Over
U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center
Geographer
mailing and physical
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
508-548-8700 x2297
whsc_data_contact@usgs.gov
The metadata contact email address is a generic address in the event the person is no longer with USGS.
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
None
None