Evan T. Dailey
2018
Structure-from-Motion (SfM) surface models derived from seafloor video from the Channel Islands, California
TIFF
data release
DOI:10.5066/P929SXZE
Pacific Coastal and Marine Science Center, Santa Cruz, California
U.S. Geological Survey
https://doi.org/10.5066/P929SXZE
https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c
Structure-from-Motion (SfM) surface models were created using seafloor video collected over a visible fault scarp in the Channel Islands, California, during a 2016 U.S. Geological Survey (USGS) field activity. Four SfM surface models were created, each with a different combination of locating, scaling, and optimizing methods. Video imagery was collected using the USGS Pacific Coastal and Marine Science Center's BOBSled, equipped with high-definition (720p) video cameras (video published in Coastal and Marine Geology Program video and photo portal, Golden and others, 2015). The sled was towed behind the R/V Shearwater and shipboard GPS locations were recorded every 1 second in the video's audio channel. The models were geolocated and scaled using either shipboard GPS or georeferencing the imagery to existing sonar bathymetry at a lower resolution (Cochrane and others, 2018). The models were optimized using either a fixed lens model or automatic calibration in the SfM software, and the files presented here are named to reflect their processing method: "AutoCal" refers to automatic calibration by the SfM software; "Cal" refers to image calibration using a fixed lens model; "Georef" refers to locations derived from georeferencing the video imagery to the existing sonar data; and "ShipGPS" refers to locations derived from the shipboard GPS embedded in the video. Each file was created using one of each of the calibration and location methods, indicated in the filename as "SfM_CalibrationMethod_LocationMethod_UTM10N."
These surface models were produced to assess the accuracy and precision of different Structure-from-Motion workflows.
Additional information about the field activity from which these data were derived is available online at:
http://cmgds.marine.usgs.gov/fan_info.php?fan=2016-668-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
20160925
20160929
ground condition
None planned
-120.275
-120.27
34.011
34.009
USGS Metadata Identifier
USGS:5bae6310e4b08583a5d30f7c
ISO 19115 Topic Category
elevation
oceans
Data Categories for Marine Planning
Bathymetry and Elevation
USGS Thesaurus
bathymetry
bathymetry measurement
sea-floor characteristics
geospatial datasets
marine geophysics
remote sensing
videography
image mosaics
Marine Realms Information Bank (MRIB) keywords
seabed
data processing
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Pacific Coastal and Marine Science Center
PCMSC
Geographic Names Information System (GNIS)
Channel Islands National Park
Channel Islands
Pacific Ocean
None
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 of the dataset and in products derived from these data. This information is not intended for navigation purposes.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-460-4747
pcmsc_data@usgs.gov
https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c?name=SfM_AutoCal-ShipGPS_vert.png&allowOpen=true
Image map of the SfM elevation model created using automatic calibration and shipboard GPS locations
PNG
Data collection was funded by U.S. Geological Survey
Microsoft Windows 7 Service Pack 1 with Esri ArcGIS version 10.5.0.6491
Guy R. Cochrane
David P. Finlayson
Evan T. Dailey
2018
Bathymetry data collected in 2007 from the San Miguel Passage in the Channel Islands, California
data release
DOI:10.5066/F78G8HVC
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/F78G8HVC
Nadine E. Golden
Seth D. Ackerman
Evan T. Dailey
2015
Coastal and Marine Geology Program video and photograph portal
data release
DOI:10.5066/F7JH3J7N
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/F7JH3J7N
The horizontal and vertical accuracies of the surface models were compared against existing sonar data (Cochrane and others, 2018). The scale accuracy of the surface models was compared by measuring the camera sled's scale laser as it appeared in the original still frames and the still frames after being aligned and located in the SfM software.
All data fall within expected ranges.
Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
Assessing the true horizontal accuracy of the models is prone to uncertainty because they were compared against lower-resolution sonar data. The sonar data had a horizontal accuracy of no less than 2 m. The horizontal accuracy of the SfM models ranged from approximately 0 to 5 m as compared to the sonar data. Overall horizontal accuracy is assumed to be no less than 2 m and no greater than 10 m. The average horizontal scaling of all the models is estimated to be accurate to within 1.25 cm, and 0.15 on average in the model created using shipboard GPS and automatic calibration.
Estimated to be 0.6 meters different than the sonar data, on average. The sonar data had a vertical accuracy estimated to be no less than 5 percent water depth. The average vertical scaling of all the models is estimated to be accurate to within 1.25 cm, and 0.15 on average in the model created using shipboard GPS and automatic calibration.
Data Collection: Video was collected during USGS field activity 2016-668-FA in the Channel Islands, CA. Video footage was collected using the USGS camera sled, which was equipped with two high resolution video cameras, one pointing downward (vertical) and the other pointing slightly forward (oblique) and was towed by the research vessel Shearwater. The camera sled was also equipped with paired lasers to provide scaling to features on the seafloor. Video was recorded in depths approximately 10 to 70 meters. Shipboard GPS locations were recorded every 1 second into one of the audio channels of the video using Red Hen Systems, LLC hardware.
201801
Structure-from-Motion Processing: Still frames were extracted from the video at a constant rate of 1 frame every 2/3 second. For the shipboard GPS method 6 markers were selected throughout the video imagery. Those markers were assigned latitude and longitude values from the shipboard GPS according to the playback time of that video frame, and the markers were assigned the depth from the existing sonar that corresponded to that location. For the georeferencing method, features visible in the video imagery were georeferenced to that feature where it was visible in the sonar data (7 markers were assigned this way). A lens model was developed using the BOBSled cameras to record imagery of a calibration board in a salt-water tank. That imagery was used to create a model, and the SfM software's lens model was exported as the fixed lens model. Automatic calibration by the SfM software was also used. Four models were produced: calibrated using a fixed lens model with the shipboard GPS that was embedded in the audio ("SfM_Cal-ShipGPS_UTM10N.tif"), lens model auto-calibrated by the SfM software with ship GPS ("SfM_AutoCal-ShipGPS_UTM10N.tif"), calibrated using a fixed lens model with locations derived from georeferencing the video imagery to the existing sonar bathymetry ("SfM_Cal-Georef_UTM10N.tif"), and auto-calibrated with georeferenced locations ("SfM_AutoCal-Georef_UTM10N.tif"). SfM models were created using Agisoft PhotoScan version 1.3.5. Photos were aligned in PhotoScan, iteratively 'cleaned' to reduce error using the following steps in PhotosScan: all points with reconstruction uncertainty greater than 10 were deleted (iteratively - no more than 50 percent of the models points were deleted at a time); all points with projection accuracy greater than 3 were deleted; reprojection error was reduced to 0.3 by iteratively deleting no more than 10 percent of the models points; after each of the previous steps, cameras were optimized; a dense point cloud was created in PhotoScan; digital elevation model created from dense point cloud in PhotoScan; elevation model exported as TIF image.
20180108
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
20201019
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
Grid Cell
Universal Transverse Mercator
10N
0.9996
-123.0
0.0
500000.0
0.0
coordinate pair
0.00422002
0.00422002
METERS
WGS_1984_UTM_Zone_10N
WGS 84
6378137.0
298.257223563
MLLW
1.0E-4
Meters
Explicit elevation coordinate included with horizontal coordinates
Attribute table
Table containing attribute information associated with the dataset
U.S. Geological Survey
Value
Depth relative to mean lower low water (MLLW) in meters
U.S. Geological Survey
-28.6
-36.0457
Meters
U.S. Geological Survey - ScienceBase
Mailing and Physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
1-888-275-8747
sciencebase@usgs.gov
These data are available in TIFF format (SfM_AutoCal-Georef_UTM10N.tif, SfM_Cal-Georef_UTM10N.tif, SfM_AutoCal-ShipGPS_UTM10N.tif, SfM_Cal-ShipGPS_UTM10N.tif) contained in a single zip file which also includes CSDGM FGDC-compliant metadata, and a browse image map of the data (.jpg). The TIFF data files are named with the following convention: SfM, calibration method, location method, and projected coordinate system.
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.
TIFF
Agisoft PhotoScan Professional Version 1.3.5 build 5649 (64 bit)
The .zip file contains four TIFF rasters (.tif), a browse image map, and the metadata.
No compression applied.
1264.68
https://www.sciencebase.gov/catalog/file/get/5bae6310e4b08583a5d30f7c
https://doi.org/10.5066/P929SXZE
Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data and metadata. The second link points to a landing page with metadata and data
None.
These data can be viewed with Esri ArcGIS software.
20201019
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-460-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998