U.S. Geological Survey
20170508
Single-Beam Bathymetry Data Collected in 2015 nearshore Dauphin Island, Alabama, U.S. Geological Survey (USGS). This metadata file is specific to the International Reference Frame 2000 (ITRF00) xyz point data.
Multimedia
https://doi.org/10.5066/F7BZ648W
Nancy T. DeWitt
Chelsea A. Stalk
James G. Flocks
Julie C. Bernier
Kyle W. Kelso
Jake J. Fredericks
Thomas Tuten
20170508
Single-Beam Bathymetry Data Collected in 2015 nearshore Dauphin Island, Alabama.
multimedia presentation
U.S. Geological Survey Data Release
F7BZ648W
St. Petersburg, Florida
U.S. Geological Survey
https://doi.org/10.5066/F7BZ648W
Dauphin Island, Alabama is a barrier island located in the Gulf of Mexico that supports local residence, tourism, commercial infrastructure, and the historical Fort Gaines. During the past decade the island has been impacted by several major hurricanes (Ivan, 2004; Katrina, 2005; Isaac 2012). Storms along with sea level rise, presents a continued threat to island stability. State and federal managers are taking a scientific investigative approach to identify the best options available to formulate and implement a long-term plan to properly restore Dauphin Island and provide resilience against future storms and sea-level rise. Island morphology, including current bathymetry data, is one of several aspects being investigated and funded through a grant from National Fish and Wildlife Foundation Gulf Environmental Benefit Fund. In August 2015, the United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC) in cooperation with the United States Army Corps of Engineers (USACE) and the state of Alabama conducted bathymetric surveys of the nearshore waters surrounding Dauphin Island. This data release provides 1,165-line kilometers (km) of processed single-beam bathymetry (SBB) data collected by the USGS SPCMSC in August 2015 (Field Activity Number [FAN] 2015-326-FA). Data were acquired aboard 4 separate survey vessels; the RV Sallenger (subFAN, 15BIM10), the RV Jabba Jaw (subFAN, 15BIM11), the RV Shark (subFAN, 15BIM12), and the RV Chum (subFAN, 15BIM13). The data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-47.04 meters [m] to -29.36 m); 2) the North American Datum of 1983, realization of CORS96 (NAD83 (CORS96)) horizontal, and the North American Vertical Datum 1988 (NAVD88) vertical (-0.24 m to -17.33 m); and 3) the NAD83 (CORS96) horizontal, and Mean Lower Low Water (MLLW) vertical (-0.12 m to -17.93 m). Additional files include trackline shapefiles, digital and handwritten Field Activity Collection Systems (FACS) logs, a comprehensive 50-meter Digital Elevation Model (DEM), and formal Federal Geographic Data Committee (FGDC) metadata.
This zip archive contains processed x,y,z data points for the single-beam bathymetry data (SBB) collected in August 2015 (FAN=2015-326-FA; SubFans=15BIM10, 15BIM11, 15BIM12 and 15BIM13) around Dauphin Island, Alabama. The processed single-beam soundings are provided as ASCII x,y,z point data.
The single-beam surveys were acquired and processed to a geodetic reference ellipsoid. The single-beam data was acquired using stand-alone GPS and then post-processed to obtain Differential Global Positioning System DGPS navigation. All single-beam surveys were referenced to WGS84 (G1150)/ITRF00. The final x,y,z position data from each survey were merged to generate a digital elevation model (DEM) with a cell-size resolution of 50 meters.
20150819
20150825
ground condition
None planned
-88.395044
-88.037671
30.272026
30.190160
USGS Metadata Identifier
USGS:3f435d40-723b-41af-ac98-91d285d68523
ISO 19115 Topic Category
oceans
elevation
location
geoscientificInformation
imageryBaseMapsEarthCover
USGS Thesaurus
marine geology
geophysics
bathymetry
single-beam echo sounder
field monitoring stations
digital elevation models
None
trackline
USGS
shapefile
HYPACK
single-beam bathymetry
base station
benchmark
West Dauphin Island (WDAU)Benchmark
NGS (National Geodetic Survey) Permanent Identifier (PID) BH1755
kinematic
shoreline
hydrography
ODOM Echotrach CV-100
ODOM
TSS Motion Sensor
echosounder
St. Petersburg Coastal and Marine Science Center
SPCMSC
Barrier Island Evolution Research Project
Barrier Island Mapping
15BIM10
15BIM11
15BIM12
15BIM13
2015-326-FA
DEM
Digital Elevation Model
50-meter DEM
Geographic Names Information System (GNIS)
Alabama
Gulf of Mexico
Mississippi Sound
Dauphin Island
None
datum
water
shoreline
None
August 2015
The U.S. Geological Survey requests that it be referenced as the originator of this dataset in any future products or research derived from these data.
These data should not be used for navigational purposes.
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center
Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcCatalog 10.1.0.3035
The accuracy of the data is determined during data collection. The SBB data were collected during one research effort in August, 2015, USGS FAN 2015-326-FA. This dataset that utilized four vessels and is therefore internally consistent per platform. Methods were employed to maintain data collection consistency aboard the platform. During mobilization, each piece of equipment is isolated to obtain internal and external offset measurements with respect to the survey platform. Each system has a dedicated computer, and efforts are made to utilize the same equipment and software versions on all systems. However, upgrades and changes occur and require additional setup, measurements, and notation. DGPS was always implemented for navigational accuracy in post-processing. These bathymetric data have not been independently verified for accuracy.
For the SBB, offsets between the single-beam transducers, the Ashtech antenna reference point (ARP), and the TSS motion unit were measured and accounted for on the roving vessels. All pertinent measurements were accounted for in the DGPS post processing software packages (National Geodetic Survey On-Line Positioning User Service, OPUS, and Waypoint Product Group GrafNav, version 8.6). Bar checks were also performed as calibration efforts and accounted for any drift in the echosounder.
This file represents the post-processed bathymetric data (x,y,z) collected during SBB surveys. They represent data coverage for the single-beam portion the 2015 nearshore Dauphin Island, Alabama survey, specifically FAN 2015-326-FA (SubFans 15BIM10, 15BIM11, 15BIM12, and 15BIM13). Refer to the online data release linkage for field logs, vessel platform descriptions, and other survey information; this information is directly available at https://doi.org/10.5066/F7BZ648W
These are complete post-processed xyz bathymetric data points from acoustic single-beam data collected in August 2015 from the nearshore areas of Dauphin Island, Alabama.
All static GPS base station sessions were run through the On-Line Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The base location results from OPUS were entered into a spreadsheet to compute one final coordinate and error analysis for that base location. Using the OPUS values for each day, and the total time that data were collected each day, the average daily weighted value of occupation time was calculated; longer occupation times held more value than shorter times. The final value for latitude, longitude, and ellipsoid was the weighted average of all the GPS session processed with OPUS. This value was entered in GrafNav version 8.6 as the base station coordinates. Error was calculated using output from OPUS for each day and was calculated as the absolute value of the final value minus the daily value. The maximum horizontal error of the base station coordinates used for post-processing the single-beam bathymetry was 0.00028 decimal seconds latitude and 0.00022 decimal seconds longitude for BH17 and 0.00027 decimal seconds latitude and 0.00018 decimal seconds longitude for WDAU.
0.00028
The maximum error for base stations BH17 and WDAU in latitude decimal seconds
0.00022
The maximum error for base stations BH17 and WDAU in longitude decimal seconds
All static base station sessions for BH17 and WDAU were processed through On-Line Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The base location results from OPUS were entered into a spreadsheet to compute a final, time-weighted positional coordinate (latitude, longitude, and ellipsoid height). Base-station positional error for each GPS session was calculated as the absolute value of the final position minus the session position value. SPCMSC standards define the maximum acceptable vertical error for any individual base station GPS session as less than or equal to three times the standard deviation of the ellipsoid height; any occupations exceeding this error are removed and the base station coordinates are recalculated. For BH17 base location, the standard deviation of the ellipsoid height was 0.005 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.015 m. For WDAU base location, the standard deviation of the ellipsoid height was 0.005 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.014 m.
GPS Acquisition: Two GPS base stations were erected on Dauphin Island. One base station was erected upon the National Geodetic Survey (NGS) Permanent Identifier (PID) BH1755.txt at the entrance to Fort Gaines on the eastern end of the island. The second GPS base station was erected at a temporarily installed USGS benchmark (WDAU) located on the western end of Dauphin Island just outside of the Dauphin Island Beach Parking lot. The strategically placed base stations then provided differential GPS coverage for the survey area within a 15 kilometer (km) radius of either benchmark. Each base was equipped with an Ashtech ProFlex GPS receiver which recorded the 12-channel full-carrier-phase positioning signals (L1/L2) from satellites via the Thales choke-ring antenna at a rate of 10 times per second.
The Ashtech ProFlex GPS instrument combination was duplicated on each single-beam survey vessels (rover). For the R/V Sallenger (15BIM10)and the R/V Jabba Jaw (15BIM11) the receivers were set to record their positions at a rate of 2 times per second. The R/V Shark(15BIM13)and the R/V Chum(15BIM13)recorded their GPS positions at a rate of 10 times per second.
The base receivers and the rover receiver recorded their positions concurrently at intervals equal to or slower than that of the base station throughout the survey. The GPS navigation data was acquired and processed in the World Geodetic Datum of 1984 (WGS84 G1150). For all vessels the navigation was post-processed to obtain DGPS.
2016
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Single-Beam Bathymetry Acquisition: Depth soundings were acquired aboard all vessels at 100-milliseconds (ms) using an Odom CV100 echo sounder system with a 200 kilohertz (kHz) transducer. Boat motion was recorded on the R/V Sallenger (15BIM10) and the R/V Jabba Jaw (15BIM11) at 50-ms intervals using a TSS Dynamic Motion Sensor (TSS DMS-05). The R/V Shark (15BIM12) and the R/V Chum (15BIM13) did not record boat motion. To minimize motion errors, these vessels recorded GPS at a high rate (10 times per second) and utilized a short antenna height (lever-arm) in combination with a narrow (4 degree) transducer beam. All sensor data were saved into a single raw data file (.raw) in HYPACK, with each device string referenced by a device identification code and time stamped to Coordinated Universal Time (UTC). Sound velocity measurements were collected using Sontek Castaway CTD units to record changes in water column speed of sound (SOS).
2016
HYPACK raw data files (.RAW), HYPACK target files (.TGT), and SOS files (.txt).
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Differentially Corrected Navigation Processing: The coordinate values for each of the GPS base stations (BH17 and WDAU) are the time-weighted average of values obtained from the National Geodetic Survey's (NGS) On-Line Positioning User Service (OPUS). The coordinates were imported into the post-processing software GrafNav (Waypoint Product Group) version 8.6. For post processing, the kinematic GPS data from the survey vessels were processed to the concurrent GPS data from the base stations. Steps were taken to ensure that the trajectories between the base and rover were clean and resulted in fixed positions. GPS data quality could be monitored and manipulated by analyzing the graphs, trajectory maps, and processing logs that GrafNav produces for each GPS session. If poor GPS data was identified, some common tools used to improve the solution were used. These options included, but were not limited to, omitting a satellite flagged as poor in health, excluding time-segments with cycle slips, or adjusting the satellite elevation mask angle. The final, differentially-corrected, precise DGPS positions were computed at each roving vessels respective recording rate, and then exported in American Standard Code for Information Interchange (ASCII) text format. This file then replaced the uncorrected real-time rover positions recorded during acquisition. The GPS data were processed and exported in the World Geodetic System of 1984 (WGS84) (G1150) geodetic datum.
2016
Post-processed differential navigation data for the rover (boat) in ASCII text format.
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Single-beam bathymetry processing: All data were processed using CARIS HIPS and SIPS (Hydrographic Information Processing System and Sonar Information Processing System) version 9.1.1. The raw HYPACK (15BIM10 used version 14.0.9.47; 15BIM11 used version13.0.9.28; 15BIM12 and 15BIM13 used version 2013A) data files were imported into CARIS, the differentially corrected navigation files were imported using the generic data parser tool within CARIS, and any SVP profile casts were entered and edited using the SVP editor within CARIS. The bathymetric data components (position, motion, depth, and SOS) were then merged and geometrically corrected in CARIS to produce processed x,y,z data. Next, the data were edited for outliers and then further reviewed in the Subset Editor utility for crossing status, and questionable data points or areas. The geometrically corrected point data were then exported as an x,y,z ASCII text file referenced to WGS84 (G1150), equivalent to ITRF00, and ellipsoid height in meters. The exported ASCII files were then combined into one large file for further quality assurance and quality control.
Post-processed differential navigation data files, HYPACK RAW bathymetric data files, HYPACK target (.TGT) files, and SOS (.txt) files all in ASCII text format.
2016
15BIM10_SBB_Level_03_ITRF00.txt
15BIM11_SBB_Level_03_ITRF00.txt
15BIM12_SBB_Level_03_xxx_ITRF00_Draft2.txt
15BIM13_SBB_Level_03_xxx_ITRF00_Draft2.txt
DI_2015_326_FA_SBB_Level_05_ITRF00.txt (combination of all above files)
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Single-Beam Bathymetry Error Analysis: The data were edited for outliers in the Single-Beam Editor of CARIS and then reviewed in the Subset Editor utility for crossing status and questionable data points or areas. The geometrically corrected point data were then exported as an x,y,z ASCII text file referenced to WGS84 (G1150), which is equivalent to ITRF00, and ellipsoid height in meters. This ASCII file was then imported into ArcMap version 10.3 and reviewed for outliers. An Esri ArcMap Ad-In program script was written locally to evaluate the elevation differences at the intersection of crossing lines. If discrepancies were found at a crossing, the source of the discrepancies was identified and if needed the line or segment of data points in error was statically adjusted or removed.
DI_2015_326_FA_SBB_Level_05_ITRF00.txt
2016
Dauphin_Island_2015_SBB_ITRF00_xyz.shp
Dauphin_Island_2015_SBB_ITRF00_xyz.txt
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Gridding Bathymetric data: Using Esri ArcGIS version 10.3.1, the single-beam elevations were examined for spatial distribution and vertical agreement. A triangulated irregular network (TIN) was generated with the x,y,z point data and constrained using a polygon shoreline. The polygon shoreline was created in ArcGIS version 10.3.1 from using the zero line extracted from the 2015 USGS Dauphin Island Lidar dataset. The TIN was generated using the ArcToolbox 3D Analysts Data Management Tool “Create TIN”. This TIN file was then sent through the 3D Analyst Conversion Tool “TIN to Raster” using the natural neighbor method at 50 meter (m) by 50 m spacing to produce the raster Digital Elevation Model (DEM). Lastly, the raster was clipped to the survey extent using Spatial Analyst Extract tool “Extract by Mask”. The DEM was then clipped to the raster mask using the ArcGIS Spatial Analyst "extract by raster mask" tool.
DI_2015_326_FA_SBB_Level_05_ITRF00.shp
Dauphin_2015_shoreline_ITRF00.shp
2016
Dauphin_Island_2015_ITRF00_50_DEM.tif
U.S. Geological Survey
Nancy DeWitt
Geologist
mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
This trackline file was created from the all-encompassing x,y,z point file for USGS FAN 2015-326-FA (15BIM10, 15BIM11, 15BIM12 and 15BIM13) in Esri ArcGIS version 10.3 using the XTools Pro extension, version 11.1. The x,y,z data point shapefile was sent through the "XTools" feature conversion tool, "make polylines from points". Within "XTools" feature conversion selection window, the following items were selected. The "group by field selection" was set to use the HYPACK line name attribute and the "input feature order - order by field" was set to use the FID attribute. The resultant polyline shapefile was then projected in WGS84 Universal Transverse Mercator (UTM) Zone 16 North.
DI_2015_326_FA_SBB_Level_05_ITRF00.shp
2016
Dauphin_Island_2015_SBB_ITRF00_tracklines.shp
U.S. Geological Survey
Nancy T. DeWitt
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
U.S.
(727) 502-8000
ndewitt@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20201013
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
174
686
1
Universal Transverse Mercator
16
0.9996
-87.0
0.0
500000.0
0.0
row and column
50
50
meter
Iternational Reference Frame 2000 (ITRF00)
0.1
meter
Implicit coordinate
Dauphin_Island_2015_SBB_ITRF00_xyz.txt
ASCII text file containing the processed single-beam bathymetry x,y,z point data in the International Terrestrial Reference Frame of 2000 (ITRF00).
USGS
ITRF00_X
ITRF00 X-coordinate (easting) of sample point, in meters
CARIS
365808.647
400111.044
ITRF00_Y
ITRF00 y-coordinate (northing) of sample point, in meters
CARIS
3340677.89
3349385.064
ITRF00_Lat
ITRF00 Latitude-coordinate of sample point, in decimal degrees
CARIS
30.193187
30.271236
ITRF00_Lon
ITRF00 Longitude-coordinate of sample point, in decimal degrees.
CARIS
-88.394413
-88.038008
Year
The year the data was collected
CARIS
2015
GPS_Week
The GPS week that the data point was acquired.
CARIS
1858
1859
GPS_Second
The GPS second that the data point was acquired.
CARIS
48464.679
601766.29
HYPACKLine
Line number in survey generated by HYPACK.
HYPACK
Example 15BIM10_SALL_001_1400 in which 15BIM10 denotes the USGS FAN number, SALL denotes the vessel code of R/V Sallenger, 001 denotes the line number, and 1400 denotes the time the line started recording.
Variations in FAN number and vessel code are the following:
15BIM10_SALL_001_1400 = R/V Sallenger
15BIM10_TVEE_001_1400 = R/V Jabba Jaw
15BIM10_WVR1_001_1400 = R/V Shark
15BIM10_WVR2_001_1400 = R/V Chum
DOY
Day of the year the data was collected
CARIS
232
236
Ellipsoid
ITRF00 ellipsoid height of sample point, in meters
CARIS
-47.044
-29.364
Dauphin_Island_2015_SBB_ITRF00_tracklines.shp
Esri shapefile containing the survey tracklines for the single-beam bathymetry data collected during USGS FAN 2015-326-FA which includes subfans 15BIM10, 15BIM11, 15BIM12 and 15BIM13 surveyed in August 2015 nearhore Dauphin Island, Alabama.
USGS
FID
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
Esri
Polyline ZM is the geometry type defining the features.
Year
The year the data was collected
CARIS
2015
Lenth_m
Length of survey line, in meters
Esri
1.28
27,948.06
meters
0.01
Boat
USGS vessel name from which survey data was acquired. The R/V Sallenger was used to acquire data for 15BIM10. The R/V Jabba Jaw was used to acquire data for 15BIM11. The R/V Shark was used to acquire data for 15BIM12, and the R/V Chum was used to acquire data for 15BIM13.
USGS
USGS research vessel name
HYPACKLine
Trackline name assigned by HYPACK-A Xylem Brand acquisition software version 14 for 15BIM10 and version 13 for 15BIM11, 15BIM12, and 15BIM13 with the USGS FAN number appended to the beginning of the file. Example 15BIM10_SALL_001_1400 in which 15BIM10 denotes the USGS FAN number, SALL denotes the vessel code of R/V Sallenger, 001 denotes the line number, and 1400 denotes the time the line started recording.
Variations in FAN number and vessel code are the following:
15BIM10_SALL_001_1400 = R/V Sallenger
15BIM11_TVEE_001_1400 = R/V Jabba Jaw
15BIM12_WVR1_001_1400 = R/V Shark
15BIM13_WVR2_001_1400 = R/V Chum
HYPACK
15BIM10_001_1554
15BIM13_142_2159
DOY
Day of year the trackline was surveyed.
USGS
232
236
USGS_FAN
The USGS FAN number assigned to the survey vessel and survey type. 15BIM10 = RV Sallenger, 15BIM11 = RV Jabba Jaw, 15BIM12 = RV Shark, and 15BIM13 = RV Chum.
USGS
USGS FAN Number as assigned.
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Dauphin_Island_2015_SBB_ITRF00_xyz.zip, Dauphin_Island_2015_ITRF00_50_DEM.zip, Dauphin_Island_2015_ITRF00_tracklines.zip
This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
ASCII, shafefile, and DEM
ZIP
146.661
https://coastal.er.usgs.gov/data-release/doi-F7BZ648W/data/Dauphin_Island_2015_SBB_ITRF00_xyz.zip
https://coastal.er.usgs.gov/data-release/doi-F7BZ648W/data/Dauphin_Island_2015_SBB_ITRF00_50_DEM.zip
https://coastal.er.usgs.gov/data-release/doi-F7BZ648W/data/Dauphin_Island_2015_SBB_ITRF00_tracklines.zip
none
The ASCII text files contained in the .zip archive can be accessed with any standard text file reader.
2017
20201013
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
ndewitt@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
The U.S. Geological Survey requests that it be referenced as the originator of this dataset in
any future products or research derived from these data.
none
unclassified
None