U.S. Geological Survey
2021
Digital surface model representing Head of the Meadow Beach, Truro from images taken during field activity 2020-015-FA on March 6, 2020
1.0
raster digital data
data release
DOI:10.5066/P9KSG1RQ
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/P9KSG1RQ
https://cmgds.marine.usgs.gov/data/field-activity-data/2020-015-FA/
C. Sherwood
P. Traykovski
J. Over
J. Borden
S. Brosnahan
E. Marsjanik
M. Martini
2021
Topographic and bathymetric data, sediment samples, and imagery collected at Head of the Meadow Beach, Truro in March 2020, U.S Geological Survey Field Activity 2020-015-FA
1.0
raster digital files
data release
DOI:10.5066/P9KSG1RQ
Reston, VA
U.S. Geological Survey
Over, J.R., Sherwood, C.R., Traykovski, P., Brosnahan, S.M., Martini, M.A., Marsjanik, E., Borden, J., 2021, Topographic and bathymetric data, sediment samples, and beach imagery collected at Head of the Meadow, Truro in March 2020, U.S Geological Survey Field Activity 2020-015-FA: U.S Geological Survey data release, https://doi.org/10.5066/P9KSG1RQ.
https://doi.org/10.5066/P9KSG1RQ
The data in this release map the beach and nearshore environment at Head of the Meadow Beach in Truro, MA and provide environmental context for the camera calibration information for the 2019 CoastCam installation that looks out at the coast shared by beachgoers, shorebirds, seals, and sharks. This is related to the field activity 2020-015-FA and a collaboration with the National Park Service at Cape Cod National Seashore to monitor the region that falls within the field of view of the CoastCam, which are two video cameras aimed at the beach. On March 4, 6, and 10, 2020, U.S Geological Survey and Woods Hole Oceanographic Institution (WHOI) scientists conducted field surveys to collect position and orientation information for the CoastCam cameras and map the field of view. Elevation data were collected using a real time kinematic – satellite navigation system (RTK-GNSS) receiver attached to a pole and walked on the beach. Point data of the beach face were collected along transects and at periodic locations of plywood targets moved throughout the day within the CoastCam view. Grain-size analysis was performed on sediment samples collected with a spade along multiple profiles from the bluff base to the intertidal zone. Images of the beach were taken with a camera (Ricoh GRII) and a post-processed kinematic (PPK) system attached to a kitesurfing kite, and high-precision targets (AeroPoints) were used as ground control points. Bathymetry was collected in the nearshore using a single-beam echosounder mounted on a surf capable self-righting electric autonomous survey vehicle. Agisoft Metashape (v. 1.6.1) was used to create a digital elevation model with the collected imagery and this was merged with the bathymetry in MatLab (v. 2020) to create a continuous topobathy product.
This digital elevation model, as constructed using structure-from-motion from the images in the 2020015FA_Truro_f1.zip and 2020015FA_Truro_f2.zip files, represents 0.1778 square kilometers of Head of the Meadow Beach in view of the CoastCam cameras on March 6, 2020.
For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2020-015-FA.
20200306
20200306
ground condition
Not planned
-70.08026794
-70.07504847
42.05323850
42.04944175
USGS Metadata Identifier
USGS:d286f22c-685d-41fb-b5cf-c63d22a74302
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Woods Hole Coastal and Marine Science Center
WHCMSC
Structure from Motion
USGS Thesaurus
remote sensing
digital elevation models
datasets
ISO 19115 Topic Category
geoscientificInformation
elevation
None
USA
Truro
Massachusetts
Head of the Meadow Beach
Cape Cod National Seashore
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.
Jin-Si Over
U.S. Geological Survey
mailing and physical address
U.S. Geological Survey
Woods Hole
MA
02543-1598
508-548-8700 x2269
jover@usgs.gov
2020015FA_Truro_DSM_browse.JPG
Height-colored image of topography data collected on Head of the Meadow Beach, Truro MA
JPG
The postional information used on the kite and ground control point datasets and metadata are available in the imagery and navigational components of the larger work citation.
All data fall into expected ranges except for points near and offshore of the waterline, where the data returned can be noisy and may result in erroneous measurements. This is a digital surface model (DSM) and includes returns from vegetation.
The structure-from-motion process that builds the Digital Surface Model uses all the available imagery and location information at the start, however not all images may align in the software to produce the final product. Users are advised to read the rest of the metadata record carefully for additional details.
Navigation information was aquired from a GNSS receiver (EMLID Reach M2) in PPK mode with a Multi-band GNSS antenna that has an estimated horizontal accuracy of 5 meters.
The location information was aquired from a GNSS receiver (EMLID Reach M2) in PPK mode with a Multi-band GNSS antenna and hotshoe adapter with an estimated vertical accuracy of 5 m. The ground control points used have centimeter vertical accuracies.
Digital Surface Model was created in Agisoft Metashape v. 1.6.1 using the following steps:
1. Project created, imagery (located in larger work citation 2020015FA_Truro_f1.zip and 2020015FA_Truro_f2.zip) and position (located in larger work citation 2020015FA_Truro_f1_photolocations.csv and 2020015FA_Truro_f2_photolocations.csv) data were brought in using the NAD83(2011) datum.
2. Photos were aligned at high accuracy (the pixels are not subsampled for increased processing speed) with a keypoint limit of 40,000 and unlimited tie points. Alignment uses the positions and matching pixels between images to create point clouds and put the imagery into a realworld spatial context. Photos that failed to align/find tie points contained breaking waves and water, but are kept in the project to reconstruct the orthomosaic because they are still spatially orientated even if they do not contribute to the elevation model. Metashape software refined and optimized the camera positions and lens model in a least squares sense to minimize the reprojection error or the distance between the measured points and the software created points.
3. Eleven ground control points (GCPs) (2020015FA_Truro_nav_AeroPoints.csv located in the larger work citation were added to the project in NAD83(2011) and manually placed on the images as markers.
4. A dense point cloud was generated using high quality (images are not subsampled) and a low frequency filtering algorithm. Accuracies for the GCPs were set 0.01 m and accuracies for the camera positions were set to 0.05 m, resulting in a total GCP error of 0.21 m. The dense point cloud was then edited to remove noise by filtering by point confidence before generating a digital elevation model (the software calls all models elevation models, but technically it is a surface model because it includes non bare earth returns, a terrain model would be only bare earth returns).
5. The digital surface model is exported from the software at a resolution of 25 cm and in NAD83(2011)/UTM Zone 19N (ESPG:6348) and GEOID 12B NAVD88 in meters.
20200323
Peter Traykovski
Woods Hole Oceanographic Institue
Associate Scientist
mailing and physical address
226 Woods Hole Rd, MS #12
Woods Hole
MA
02543
508-289-2638
ptraykovski@whoi.edu
Corrected a thesaurus keyword.
20210514
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Raster
Pixel
1666
1708
Universal Transverse Mercator
19
0.999600
-69.000000
0.000000
500000.000000
0.000000
row and column
0.25
0.25
meters
North American Datum of 1983 (National Spatial Reference System 2011)
GRS_1980
6378137.000000
298.257222101
North American Vertical Datum of 1988
0.001
meters
Explicit elevation coordinate included with horizontal coordinates
Pixels represent elevation in meters relative to North American Vertical Datum of 1988 (NAVD88). GeoTIFF was created from the dense point cloud in Agisoft Metashape with interpolation enabled. The no-data value is -32767.
USGS Field Activity 2020-015-FA
Jin-Si Over
U.S. Geological Survey
geographer
mailing and physical
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
508-548-8700 x2269
jover@usgs.gov
GeoTIFF file 2020015FA_Truro_DSM_25cm.tif as a 32-bit floating point digital surface model (DSM).
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
GeoTIFF file containing 32-bit floating point DSM of Head of the Meadow Beach, Truro MA on March 6, 2020.
2.961
https://cmgds.marine.usgs.gov/data/field-activity-data/2020-015-FA/
https://doi.org/10.5066/P9KSG1RQ
The first link in the list above is to the field data page and the second link is to the publication landing page.
None.
20210514
Jin-Si Over
U.S. Geological Survey
geographer
mailing and physical
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
508-548-8700 x2269
jover@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
None
None