U.S. Geological Survey
2018
Braddock West orthomosaic from low-altitude aerial imagery from unmanned aerial systems (UAS) flights over of the Lake Ontario shoreline in the vicinity of Braddock Bay, New York in July 2017 (GeoTIFF image).
1.0
raster digital data
data release
DOI:10.5066/F74F1PX3
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.5066/F74F1PX3
https://www.sciencebase.gov/catalog/item/5a5cb308e4b06e28e9bcd23e
Christopher R. Sherwood
Sandra M. Brosnahan
Seth D. Ackerman
Jonathan Borden
Ellyn T. Montgomery
Elizabeth A. Pendleton
Emily J. Sturdivant
2018
Aerial imagery and photogrammetric products from unmanned aerial systems (UAS) flights over the Lake Ontario shoreline at Braddock Bay, New York, July 10 to 11, 2017
1.0
data release
DOI:10.5066/F74F1PX3
Reston, VA
U.S. Geological Survey
Suggested citation: Sherwood C.R., Brosnahan S.M., Ackerman S.D., Borden Jonathan, Montgomery E.T., Pendleton E.A., and Sturdivant, E.J., 2018, Aerial imagery and photogrammetric products from unmanned aerial systems (UAS) flights over the Lake Ontario shoreline at Braddock Bay, New York, July 10 to 11, 2017: U.S. Geological Survey data release, https://doi.org/10.5066/F74F1PX3.
https://doi.org/10.5066/F74F1PX3
https://www.sciencebase.gov/catalog/item/5a329336e4b08e6a89d88012
Low-altitude (80-100 meters above ground level) digital images were obtained from a camera mounted on a 3DR Solo quadcopter, a small unmanned aerial system (UAS), in three locations along the Lake Ontario shoreline in New York during July 2017. These data were collected to document and monitor effects of high lake levels, including shoreline erosion, inundation, and property damage in the vicinities of Braddock Bay, Sodus Bay, and Chimney Bluffs State Park, New York. This data release includes images tagged with locations determined from the UAS GPS; tables with updated estimates of camera positions and attitudes based on the photogrammetric reconstruction; tables listing locations of the base stations, ground control points, and transect points; geolocated, RGB-colored point clouds; orthomosaic images; and digital elevation models for each of the survey regions. Collection of these data was supported by the Federal Emergency Management Agency, the State of New York Departments of State and Environmental Conservation, and the USGS Coastal and Marine Geology Program and was conducted under USGS field activity number 2017-042-FA.
The orthomosaic image provides the optical surface reflectance of the land surface at mid-day low-tide on 10 July, 2017 in the Braddock Bay West study area. It was one of three products created to demonstrate the use of structure-from-motion for coastal research and to provide a means to test land cover classification from high-resolution imagery.
For more information about this field activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-042-FA. An orthomosaic is distinct from an orthophoto mosaic in that it corrects for camera lens distortion and preserves distances. Thus, an orthomosaic simulates a photo in which every pixel in the scene was captured at nadir.
20170710
ground condition
None planned
-77.713892
-77.699990
43.312404
43.303836
USGS Metadata Identifier
USGS:5a5cb308e4b06e28e9bcd23e
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Coastal and Marine Science Center
WHCMSC
State of New York Department of State
State of New York Department of Environmental Conservation
Federal Emergency Management Agency
shoreline
lake level
3DR Solo quadcopter
Ricoh GRII
low-altitude aerial imagery
aerial imagery
shoreline photographs
photographs
photos
UAS
Unmanned aerial system
lakeshore
Orthophoto
Orthomosaic
photo mosaic
GeoTIFF
raster
field activity number 2017-042-FA
USGS Thesaurus
remote sensing
aerial photography
image mosaics
ISO 19115 Topic Category
geoscientificInformation
inlandWaters
location
None
USA
Great Lakes
New York
Lake Ontario
Braddock Bay Wildlife Management Area
Braddock Bay
Greece, NY
Braddock Point
Westpoint Marina
Braddock Bay Park
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 as the originator of the dataset.
U.S. Geological Survey
Sandra Brosnahan
Physical Scientist
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543-1598
508-548-8700 x2265
508-457-2310
sbrosnahan@usgs.gov
https://www.sciencebase.gov/catalog/file/get/5a5cb308e4b06e28e9bcd23e/?name=2017042FA_BraddockWest_Orthomosaic_browse.jpg
Browse image of a portion of an orthomosaic generated from photogrammetry and low-altitude aerial images obtained with unmanned aerial systems (UAS).
JPEG
All data were handled in a consistent manner. Photoscan software determines the photos used in the construction of the products (Point Cloud, DEM and Orthomosaic) based on the ability to align the photo and the usability of valid tie points within an image. A tie point represents a point that the software determine to be common from one photo to the next. The camera locations CSV file in this data release (https://doi.org/10.5066/F74F1PX3) indicates which photos were used to create the final products. The final point cloud used to construct this dataset was checked for accuracy by rotating the point cloud to view from multiple angles to ensure that obvious spurious points do not cause artifacts in the derivative products (DEM and Orthomosaic).
This orthomosaic was created from the filtered tie-points of the dense point cloud using the Agisoft Photoscan Professional (v. 1.3.2) photogrammetry software. Through a standardized filtering process, spurious points from the dense point cloud were eliminated and remaining point cloud was used to generate a digital elevation model, which was subsequently used to create this orthomosaic. The completed Photoscan project for Braddock West, from which this orthomosaic was created, used 1091 of the original 1175 images and contained more than 158 million points. The point cloud and the DEM are available in this data release at https://doi.org/10.5066/F74F1PX3. To minimize the effects of changing environmental factors (e.g. shadows, lighting, etc) on the final products, the BraddockWest photogrammetry project contains only imagery from flights on July 10, 2017.
Horizontal positions of individual points for the point cloud, from which this was constructed, were calculated by photogrammetric software and ground control points. There are several sources of potential error that affect the horizontal accuracy:
1. The horizontal error estimate provided by Agisoft Photoscan for the Braddock West project as a result of alignment, optimization, and ground control processing procedures is 1.0 cm. This value is an RMS estimate of positional error at discrete locations within the orthomosaic.
2. Ground control points were collected using a Spectra model SP80 GNSS receiver set to record XY locations with the national adjustment of 2011 (NAD83(2011) UTM zone 18N EPSG::6347), which differs from the Photoscan project coordinate system (NAD83/UTM zone 18N (EPSG::26918)). This difference may introduce an average additional 0.9 cm horizontally at the 95% confidence level according to the National Geodetic Survey (https://www.ngs.noaa.gov/web/surveys/NA2011/).
3. Additionally, an assessment of repeated survey sites (transect points) using the same equipment by the USGS Aerial Imagery and Mapping group (AIM) estimates an accuracy of the ground control point locations of 1.76 cm (horizontal) and 0.54 cm (vertical).
The combination of the potential horizontal error is on the order of 3.66 cm for the Braddock West products. Although some portions of the map may contain much larger errors, up to 2 m horizontally. The horizontal coordinate system for the Braddock West Point Cloud, DEM and Orthomosaic is NAD83/UTM zone 18N (EPSG::26918).
It is also important to note: The UAS image locations are derived from a mRo GPS (u-Blox Neo-M8N / 3DR SOLO Upgrade), located on the UAS, which receives signals from GPS and GLONASS satellites in WGS84 (G1150) EPSG::7660. This location information is used by the Photoscan software to help with the initial alignment, however after photo alignment, these location data have no bearing on the project or the derivative product. Therefore the positional accuracy and potential errors of the GPS data attached to the input photographs is not propagated to the Photoscan project and therefore does not contribute to the overall horizontal accuracy of the products (Point Cloud, DEM and Orthomosaic).
U.S. Geological Survey
2018
Geotagged low-altitude aerial imagery from unmanned aerial systems (UAS) flights over of the Lake Ontario shoreline in the vicinity of Braddock Bay, New York, USA in July 2017
data release
DOI:10.5066/F74F1PX3
Reston, VA
U.S. Geological Survey
https://doi.org/10.5066/F74F1PX3
raster digital images
20170710
20170711
ground condition; images were obtained between 20170710 and 20170711.
geotagged aerial digital images
The digital images are the raw data used to produce subsequent photogrammetric products.
U.S. Geological Survey
2018
Ground control point and transect locations associated with images collected during unmanned aerial systems (UAS) flights over the Lake Ontario shoreline in the vicinity of Braddock Bay, New York, USA in July 2017
data release
DOI:10.5066/F74F1PX3
Reston, VA
U.S. Geological Survey
https://doi.org/10.5066/F74F1PX3
text data files
20170710
20170711
ground condition; ground control points were obtained between 20170710 and 20170711.
text files with ground control point (GCPs)
The ground control points (GCPs; not transect points -- see metadata for more information) were used to geolocate the photogrammetric products.
Orthomosaics for the Lake Ontario projects were constructed using photogrammetry software (Agisoft Photoscan Professional v. 1.3.2) and digital images taken approximately 80 and 100 m above the ground on July 10 - 14, 2017, with a Ricoh GRII digital camera mounted in a 3DR Solo quadcopter operated the U.S. Geological Survey. This orthomosaic is the product from one of several photogrammetry projects from field activity 2017-042-FA. Two projects incorporated flights over Braddock Bay on July 10 and 11, 2017 (Braddock West, Braddock East); four were used for flights in the vicinity of Sodus Bay on July 12, 13, and 14, 2017 (Lake Bluff / Crescent Bar, Crescent Bar / Charles Point, Sodus North, and Greig Street); and one project incorporated flights over Chimney Bluffs on July 14, 2017. The projects combined images with 5 to 27 ground control points to produce geolocated, colored (red-green-blue schema) point clouds. This orthomosaic, for the Braddock West project, was created using a standard processing flow as described in the processing step below.
201709
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
Christopher R. Sherwood
Research Oceanographer
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543
U.S.A.
508-548-8700 x2269
508 457 2310
csherwood@usgs.gov
The following steps make up the general processing flow for creating orthomosaics from UAS flights:
1. Geotagged images (see source citation) containing useful imagery from the survey area were imported into Agisoft Photoscan Professional v. 1.3.2 software using the “Add photos…” tool. Photos taken before and immediately after takeoff, photos taken immediately prior to and after landing, and photos with 100% water were not loaded into the project. Project coordinate system is set to EPSG::7660 WGS84 (G1150) geocentric coordinate system.
2. Using ”Convert”, the coordinate system of the images (called “cameras” in Photoscan) was converted from native latitude/longitude WGS84 (G1150) coordinate system to meters in NAD83/UTM zone 18N (EPSG::26918).
3. The photos were processed through an initial alignment and optimization procedure using the following settings:
Alignment - Accuracy: “High”; Pair selection: “Reference”; Key point limit: 80,000; Tie point limit; 0 (unlimited). Adaptive camera model fitting option was selected.
Optimization - Lens-calibration parameters f, cx, cy, k1, k2, k3, p1, and p2 were included; b1, b2, and higher-order parameters k4, p3, and p4 were not.
4. The sparse point cloud (also known as tie points; created as a result of photo alignment and optimization) was edited using an iterative error-reduction procedure to filter the data. This was done in several iterations of a process called "Gradual Selection" to first to reduce reconstruction uncertainty (to a unitless value of 10) and then projection accuracy (to a weighted value of 3).
5. Ground control points were created by first by letting the software automatically detect markers where it finds all of the 4-ft square black/white targets deployed (false targets that are sometimes detected were manually deleted). The automatically-generated marker labels were manually changed to match the names in the survey notes and GCP location files.
6. "Import markers” was used to load the GCP location file, which assigned coordinates (northing, easting, and elevation in UTM Zone 18 North meters in NAD83 and NAVD88 coordinate systems) from the location file to the detected markers. The locations of auto-detected markers were retained.
7. Another round of "Gradual Selection" was done to reduce the reprojection error (to a value of 0.3 pixels, unless more than 10% of the points would be removed).
8. A dense point cloud was then created with the parameters "High" quality and “Aggressive” depth filtering.
9. A DEM was create with the parameters Source data="Dense Cloud" Interpolation="Enabled" Resolution="0.05"
10. An orthomosaic was create with the parameters Surface="DEM" Blending mode="Mosaic" Pixel size X="0.025" Pixel size Y="0.025"
11. The orthomosaic was exported in GeoTIFF format (2017-07-10_Braddock_West_ORTHO_2pt5cm.tif) along with a world file (tfw), then both were renamed to the AIM Data Release filenaming standard (e.g. 2017042FA_BraddockWest_Orthomosaic.tif).
20170913
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
Christopher R. Sherwood
Research Oceanographer
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543
U.S.A.
508-548-8700 x2269
508 457 2310
csherwood@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20200807
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
36680
43960
Universal Transverse Mercator
0.999600
-75.00000
0.000
500000.0000
0.0000
coordinate pair
0.025
0.025
meters
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222101
There are no attributes associated with this GeoTIFF. This is a 4-band (each is 8-bits) orthomosaic in GeoTIFF format. Band1=RedBand, Band2=GreenBand, Band3=BlueBand, Band4=transparency
U.S. Geological Survey
U.S. Geological Survey - ScienceBase
mailing and physical address
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
1-888-275-8747
sciencebase@usgs.gov
This data release contains an orthomosaic in GeoTIFF format (2017042FA_BraddockWest_Orthomosaic.tif) the world file (2017042FA_BraddockWest_Orthomosaic.tfw), and a browse graphic (2017042FA_BraddockWest_Orthomosaic_browse.jpg). FGDC CSDGM metadata (2017042FA_BraddockWest_Orthomosaic.xml) accompanies the data and can be found on the dataset landing page.
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 USGS 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
Agisoft Photoscan Professional v. 1.3.2 GeoTIFF
32-bit RBGA GeoTIFF
Orthomosaic (each band is an 8-bit unsigned integer) in GeoTIFF image format at 0.025 meter resolution, world file and the associated metadata.
Use WinZip, 7zip, Peazip or pkUnzip
2060
https://www.sciencebase.gov/catalog/item/5a5cb308e4b06e28e9bcd23e
https://www.sciencebase.gov/catalog/file/get/5a5cb308e4b06e28e9bcd23e
https://doi.org/10.5066/F74F1PX3
The first link is to the page containing the data, the second link downloads all data available from the page as a zip file, and the third link is to the publication landing page. Because the dataset is over 1 GB, the user should go to the main landing page (first link) and use the large file download option to obtain the data. The second link may or may not work appropriately.
none
To utilize these data an image processing or GIS software package capable of viewing a GeoTIFF image is necessary.
20200807
U.S. Geological Survey
Sandra Brosnahan
Physical Scientist
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543-1598
508-548-8700 x2265
508-457-2310
sbrosnahan@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998