U.S. Geological Survey
2021
Bathymetric grid representing single beam data during field activity 2020-015-FA offshore Head of the Meadow Beach, Truro MA on March 10, 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 2021, U.S Geological Survey Field Activity 2020-015-FA
1.0
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 bathymetric grid represents approximately 0.3764 square kilometers of nearshore single beam echo-sounder bathymetry data collected on March 10, 2020 in view of the CoastCam cameras on Head of the Meadow Beach.
For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2020-015-FA.
20200310
20200310
ground condition
Not planned
-70.07948644
-70.07272611
42.05804953
42.05190872
USGS Metadata Identifier
USGS:3ef20127-afb6-44c0-a599-b1c3a3ccde48
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Woods Hole Coastal and Marine Science Center
WHCMSC
USGS Thesaurus
remote sensing
single-beam echo sounder
bathymetry
ISO 19115 Topic Category
geoscientificInformation
oceans
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_bathymetry_browse.JPG
Depth-colored image of bathymetry data collected offshore of Head of the Meadow Beach, MA
JPG
The GNSS reciever used on the autonomous survey vehicle (ASV) has theoretical vertical and horizontal accuracies of 5 meters.
This file represents single beam echo-sounder bathymetry data collected by Peter Traykovski (WHOI). These data were combined with post-processed kinematic (PPK) orthometric heights collected using a GNSS receiver (EMLID Reach M2) mounted on a self-righting ASV corrected to a base station (JAVA Triumph) onshore in GEOID12B NAVD88 meters. The GNSS antenna is offset from the echo-sounder by 0.43 meters (referred to as Antenna_Z_Offset), and this is taken into account when calculating the depth in the trackline variables, see Processing Steps.
All collected survey line data were edited for erroneous soundings before being incorporated into the final bathymetric grid, the mask prevents extrapolation of data but does not exlcude any data.
Navigation information was acquired from the GNSS reciever in PPK mode with a Multi-band GNSS antenna that has an estimated horizontal accuracy of 5 meters.
The location information was acquired from the GNSS reciever in PPK mode with a Multi-band GNSS antenna and hot shoe adapter with an estimated vertical accuracy of 5 m.
The bathymetry was collected by launching the ASV into the water from the surf zone, the boat was controlled near the shore by Peter Traykovski and put on auto-pilot using predetermined tracklines for longer transects offshore.
The bathymetry data was processed with the following steps
1. Parsed the binary data (BU353s4 GPS Puck, Time, Position and Echosounder range) into Matlab (v. 2020b) from the EA24 Echosounder using Matlab Scripts developed by Peter Traykovski at WHOI - see contact below
2. Post Processed Kinematic (PPK) GNSS (Novatel OEM-V2_L1L2) data from the vessel was corrected using the base station (Java Triumph-1) data in Novatel Inertial Explorer (Version 8.70.8722) using the datum NAD83(2011) and then GEOID 12B for the vertical datum NAVD88. A projection for UTM Zone 19N was also specified to get the Easting and Northing information. An antenna height of 0.0 was used and then the actual antenna height is corrected for in Step 5.
3. Interpolated PPK GNSS positions and altitude (ppk_Height) to time of Echosounder samples with the MatLab function interp1 (linear interpolation).
4. Refined time alignment to account for any small time delays between GPS data and Echsounder data collection by using time lagged cross correlation of Echosounder range and PPK GNSS altitude in locations with a relatively flat bottom. The GPS measures vertical fluctuation of the boat due to waves and these flucations are also visible in echosounder data. The equation in Step 5 removes the vertical fluctuation due to waves from the echosounder data leaving only true bathymetry if GPS and the Echsounder are well synced. The lagged cross correlation processing ensures they are synced optimally.
5. Calculated sea floor elevation (referred to as depth) with reference to the NAVD88 datum in meters by the following equation: Depth = ppk_Height - Antenna_Z_Offset - Echo_altitude; Antenna_Z_Offset = 0.43 m is the offset from the GNSS antenna to the Echosounder transducer on the z-axis of the ASV.
6. Exported Trackline data to text file: 2020015FA_Truro_trackline.txt to be read into Matlab and then copied TXT file into Excel and saved as a CSV file for publication.
7. Gridded Depth onto 1 m resolution UTM eastings, northings using Matlab file exchange script regularizedata3d (cubic interpolation) with smoothness of 0.001 (used for data with low noise where the input points nearly coincide with the output surface) by Jamal (2020).
8. The Matlab function 'roipoly' returns the mask as a binary image, setting pixels inside the region of interest to 1 and pixels outside the ROI to 0. The boundary is developed so that there is no extrapolated bathymetry data outside the tracklines. The masks extent is the convex hull of the tracklines positions (x,y) and a bounding z coordinate of 0.8 representing the surface in reference to NAVD88 in meters.
9. Export gridded 1 m data in NAD83(2011)/UTM Zone 19N in NAVD88 meters as a GeoTIFF: 2020015FA_Truro_bathymetry_1m.tif
Jamal (2020). RegularizeData3D (https://www.mathworks.com/matlabcentral/fileexchange/46223-regularizedata3d), MATLAB Central File Exchange. Retrieved September 23, 2020.
20200917
Peter Traykovski
Woods Hole Oceanographic Institute
Associate Scientist
mailing and physical address
226 Woods Hole Rd, MS #12
Woods Hole
MA
02543
508-289-2638
ptraykovski@whoi.edu
Universal Transverse Mercator
19
0.999600
-69.000000
0.000000
500000.000000
0.000000
row and column
1
1
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
2020015FA_Truro_trackline.csv
The CSV file contains the post-processed navigation GNSS trackline data for the echosounder. This dataset contains 4730 records.
USGS
timedate_EST
Time position values were taken in the format dd-mmm-yyyy hh:mm:ss Eastern Standard Time (EST)
None
10-Mar-2020 15:32:25
10-Mar-2020 16:12:44
Echo_altitude
The height in meters of the data point generated from the single-beam echo-sounder transponder with reference to NAVD88.
None
1.003
10.376
meters
Latitude
Post-processed kinematic (PPK) latitude of GNSS antenna position at the moment of a valid Echo_altitude value relative to the NAD83(2011).
USGS
42.05190872
42.05804953
Decimal degrees
Longtitude
Post-processed kinematic (PPK) longitude of GNSS antenna position at the moment of a valid Echo_altitude value relative to the NAD83(2011).
None
-70.07948644
-70.07272611
Decimal degrees
Easting
Post-processed kinematic (PPK) X-coordinates in NAD83(2011)/UTM Zone 19N interpolated from valid echo-sounder altitude samples.
USGS
410681.159
411230.310
meters
Northing
Post-processed kinematic (PPK) Y-coordinates in NAD83(2011)/UTM Zone 19N interpolated from valid echo-sounder altitude samples.
USGS
4656104.184
4646778.031
meters
ppk_Height
Post-processed kinematic (PPK) height (Z-coordinates) GNSS data in reference to NAVD88 in meters of the electric autonomous survey vehicle interpolated from valid echo-sounder samples. A positive z value is the up direction.
USGS
1.612
2.334
meters
Depth
Depth refers to the elevation of the seafloor in NAVD88 in meters and is calculated by subtracting the Antenna_Z_offset (0.43 meters) and Echo-altitude from the ppk_Height (Z-coordinate).
None
-8.988
0.601
meters
There are no text attributes associated with a binary GeoTIFF file. The GeoTIFF has 552 columns and 676 rows. The pixel values are a 64-bit floating point format that represent elevation in meters relative to the NAVD88 datum. The no-data value is -32767. The trackline CSV contains post-processed navigation GNSS data as given in the Entity_and_Attribute_Information section.
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
Windows 10 zip file 2020015FA_Truro_bathymetry.zip containing a 64-bit floating point GeoTIFF 1m grid of bathymetric data (2020015FA_Truro_bathymetry_1m.tif)and corrected trackline positions and elevation values (2020015FA_Truro_trackline.csv).
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
64-bit floating point GeoTIFF format
Windows 10 zip file containing 64-bit floating point GeoTIFF representing a grid of single beam bathymetric data collected by Peter Traykovski (WHOI) during field activity 2020-015-FA offshore Head of the Meadow Beach, Truro MA in March 2020.
Use WinZip, 7zip, Peazip or pkUnzip
2.41
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.
CSV
Exported from Excel Office 365 16.01
The CSV file contains trackline data.
Use WinZip, 7zip, Peazip or pkUnzip
0.385
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.
These data are available as a 64-bit floating point GeoTIFF image. To utilize these data, the user must have an image viewer, image processing, GIS software package capable of importing a GeoTIFF image. Free spatial data viewers or proprietary software such as ArcGIS Earth or Google Earth Pro are capable of displaying the data. See: http://www.esri.com/software/arcgis-earth, or https://www.google.com/earth/desktop/. The zip file also contains associated metadata.
20210318
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