Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2016 Title: Breton2014_IFB_SBB_100_NAD83_NAVD88_UTM16N_GEOID09_DEM: A geotiff of the 100-meter cell size digital elevation model derived from the processed interferometric swath, single beam bathymetry, and Lidar data points. Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: https://pubs.usgs.gov/ds/1005/ds1005-data-downloads.html Larger_Work_Citation: Citation_Information: Originator: Nancy T. DeWitt Originator: Jake J. Fredericks Originator: James G. Flocks Originator: Jennifer L. Miselis Originator: Stanley D. Locker Originator: Jack L. Kindinger Originator: Julie C. Bernier Originator: Kyle W. Kelso Originator: B.J. Reynolds Originator: Dana S. Wiese Originator: Trevor Browning Publication_Date: 2015 Title: Archive of bathymetry and backscatter data collected in 2014 nearshore Breton and Gosier Islands, Breton National Wildlife Refuge, Louisiana. Geospatial_Data_Presentation_Form: multimedia presentation Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: 1005 Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.3133/ds1005 Description: Abstract: As part of the Barrier Island Monitoring Project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off Breton and Gosier Islands, Louisiana, in July and August of 2014. To assist the United States Fish and Wildlife Service (USFWS) with restoration planning efforts, the USGS was tasked with answering fundamental questions about the physical environment of the southern Chandeleur Islands, including the geology, morphology, and oceanography. Baseline data needed to answer these questions was either insufficient or missing in the area. The USGS conducted a comprehensive geologic investigation in the summer of 2014 by collecting geophysical and sedimentological data. Breton Island, located at the southern end of the Chandeleur Island chain, Louisiana, was recognized as a natural and globally important nesting sanctuary for several bird species and was established as the Breton National Wildlife Refuge (NWR) in 1904. The aerial extent of Breton Island has diminished 90% since 1920. Land loss is attributed to ongoing relative sea-level rise, diminished sediment supply, and storm impacts. The bird population on Breton Island has also declined over the years, most notably after Hurricane George in 1998 and Hurricane Katrina in 2015, which completely submerged the island. Despite the decreasing habitable acreage, migratory seabirds continue to return and utilize Breton Island. To prevent the island from being completely submerged in the future and to protect, stabilize, and provide more nesting and foraging areas for the birding population, the USFWS is proposing a restoration effort to rebuild Breton Island to its pre-Katrina footprint. This Data Series serves as an archive of processed interferometric-swath, single-beam bathymetry, and side-scan sonar data collected in the nearshore of Breton and Gosier Islands, NWR, Louisiana. The data were collected during two USGS cruises (USGS Field Activity Numbers 2014-314-FA and 2014-317-FA) in July and August 2014. Geographic Information System data products include a 100 meter-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee (FGDC) metadata. Purpose: This 100-meter cell size digital elevation model is an interpretive product that was derived from the processed interferometric swath, single-beam bathymetry, and Lidar data collected in July and August 2014, around the southern Chandeleur Islands, Louisiana. Supplemental_Information: The interferometric swath bathymetry navigation data was acquired with Marinestar High Precision Differential Geographic Positioning System (DGPS),which used the ITRF2005 datum. For the single-beam bathymetry, the differential positioning was obtained through post-processing the base station data to the rover data. All datasets were transformed from their initial datums (ITRF00 for SBB and ITRF05 for IFB) to NAD83 using GEOID09 (NOAA NGS VDatum software version 3.2 - http://vdatum.noaa.gov/). The final x,y,z position data was gridded at a 100-meter cell size resolution to create the digital elevation model. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2014 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: none Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -89.303995 East_Bounding_Coordinate: -89.013844 North_Bounding_Coordinate: 29.598653 South_Bounding_Coordinate: 29.371525 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:681e845a-63a2-4dba-990d-d9b486358875 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: geoscientificInformation Theme_Keyword: imageryBaseMapsEarthCover Theme_Keyword: oceans Theme: Theme_Keyword_Thesaurus: General Theme_Keyword: marine geology Theme_Keyword: bathymetry Theme_Keyword: interferometry Theme_Keyword: swath Theme_Keyword: CARIS Theme_Keyword: HIPS and SIPS Theme_Keyword: hydrography Theme_Keyword: geophysical Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: CMGP Theme_Keyword: St. Petersburg Coastal and Marine Science Center Theme_Keyword: SPCMSC Theme_Keyword: Barrier Island Mapping Theme_Keyword: Interferometric Bathymetry Theme_Keyword: 2014-314-FA Theme_Keyword: Digital Elevation Model Theme_Keyword: 2014-317-FA Theme_Keyword: 14BIM01 Theme_Keyword: 14BIM02 Theme_Keyword: 14BIM03 Theme_Keyword: 14BIM05 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Louisiana Place_Keyword: Gulf of Mexico Place_Keyword: Chandeleur Islands Place_Keyword: Chandeleur Sound Place_Keyword: Breton Island Place_Keyword: Gosier Islands Place_Keyword: Breton Island National Wildlife Refuge Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: datum Stratum_Keyword: water Stratum_Keyword: shoreline Temporal: Temporal_Keyword_Thesaurus: None Temporal_Keyword: July 2014 Temporal_Keyword: August 2014 Access_Constraints: None Use_Constraints: 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: Mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Data_Set_Credit: Funds for this report are part of project funds for the Louisiana Outer Coast Early Restoration Project, obtained by the natural resource trustees for the Deepwater Horizon Oil Spill, pursuant to the Framework for Early Restoration Addressing Injuries Resulting from the Deepwater Horizon Oil Spill executed April 20, 2011. USFWS is the project lead for the North Breton Island Barrier Island Restoration project. Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. Native_Data_Set_Environment: Microsoft Windows 7 Service Pack 1; Esri ArcGIS 10.1 Service Pack 1 Build 3143; Esri ArcCatalog 10.1 Build 3143 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The accuracy of the data is determined during data collection. The single-beam and interferometric swath bathymetry data were collected during two research cruises, one in July 2014 and the other in August 2014. Methods are employed to maintain data collection consistency aboard various platforms. During mobilization, each piece of equipment (single-beam and swath) is isolated to obtain internal and external offset measurements with respect to the survey platform. All the critical measurements are recorded manually and digitally and entered into their respective programs for calibration. Once calibration is complete and calibration status is considered acceptable, survey operations commence. Each system has a dedicated computer, and efforts are made to utilize the same equipment and software versions on both systems. However, upgrades and changes occur and require additional setup, measurements, and notation. For the single-beam bathymetry, offsets between the single-beam transducers and the Ashtech antenna reference point (ARP) were measured and accounted for in post-processing. Bar checks were performed as a calibration check and accounted for any drift in the echosounder. Differential Global Positioning System (DGPS) coordinates were obtained using post-processing software packages (National Geodetic Survey On-Line Positioning User Service, OPUS, and Waypoint Product Group GrafNav, version 8.5). For the interferometric swath bathymetry, offsets between the sonar head and the DGPS antennas were measured and entered into the CodaOctopus F190R internal setup program. DGPS was provided through the Marinestar High Performance wide-area GPS service by Fugro, Inc. DGPS is always implemented for navigational accuracy either during acquisition or as a post-processing step. These bathymetric data have not been independently verified for accuracy. Logical_Consistency_Report: The interferometric swath and single beam bathymetry data were collected during two research cruises one in July 2014 and the other in August 2014 (2014-314-FA and 014-317-FA respectively. Refer to the online data series linkage for field logs, vessel platform descriptions, and other survey information available at http://pubs.usgs.gov/ds/1005/ds-logs. The single-beam and interferometric swath bathymetry data were collected during two research cruises, one in July 2014 and the other in August 2014 (2014-314-FA and 2014-317-FA, respectively). These datasets were merged to provide a single post-processed bathymetric digital elevation model (DEM) at 100-meter cell-size resolution. The data gaps between acquisition tracklines are predicted values generated by the gridding algorithm. These bathymetric data have not been independently verified for accuracy. Completeness_Report: This is a completely processed digital elevation model representing an interpolated bathymetric surface derived from the acoustic interferometric single-beam and swath bathymetry data. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: All static base station sessions were processed 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 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. The maximum horizontal error of the base station coordinates used for post-processing the single-beam bathymetry was 0.00060 seconds latitude and 0.00125 seconds longitude for the USGS benchmark, BRET, and 0.00023 seconds latitude and 0.00030 seconds longitude for BRT2. The stated horizontal accuracy of the Marinestar HP navigation subscription used during swath bathymetry acquisition is reported by the service as +/-15 cm (95% of the time). Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 0.00060 Horizontal_Positional_Accuracy_Explanation: latitude decimal degrees Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 0.00125 Horizontal_Positional_Accuracy_Explanation: longitude decimal degrees Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: All static base station sessions for BRET and BRT2 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 the BRET base station location, the standard deviation of the ellipsoid height was 0.014 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.036 m. For the BRT2 base station location, the standard deviation of the ellipsoid height was 0.012 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.029 m. All the processed single-beam bathymetry data (x,y,z) for 2014 are referenced to these base station coordinates. The differentially corrected navigation files (base station GPS processed to boat GPS) were exported from GrafNav version 8.5 and then imported into CARIS HIPS and SIPS version 8.1.7 and merged, by time, with the HYPACK (versions 13.0.9.17 and 14.0.9.47) raw data files at which point the soundings are then geometrically corrected for motion and speed of sound. The vertical accuracy for the SWATHplus-H system varies with depth and across track range. At 57 m it is accurate to 10 cm vertically. Maximum vertical transformation error reported by VDatum is 0.171 m or 17.1 centimeters for eastern Louisiana. The sum of the errors ([+/- 0.013 m] + [+/-0.15 m] +[0.171 m]) in the vertical direction is equal to +/-.334 m or +/- 33.4 cm. Lineage: Process_Step: Process_Description: GPS Acquisition: A GPS base station was erected at a temporarily installed USGS benchmark (BRET) located on the sound side of the Chandeleur Islands. A second base station (BRT2) was temporarily installed on top of a short piling located approximately 0.40 km southwest of the BRET base location to provide a backup base station. GPS receivers recorded the 12-channel full-carrier-phase positioning signals (L1/L2) from satellites via the Thales choke-ring antenna at the base stations. A similar GPS instrument combination was duplicated on the survey vessel (rover). The base receivers and the rover receivers recorded their positions concurrently at the same time intervals (1.0-second(s) for 14BIM02 and 0.1-s for 14BIM03) throughout the survey. Process_Date: 2014 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Single-Beam Bathymetry Acquisition: The single-beam bathymetric data were collected aboard the 22-foot R/V Jabba Jaw and a 15 ft Personal Water Craft (PWC) R/V Chum Bucket. Boat motion was recorded at 50-millisecond (ms) intervals using a Teledyne TSS Dynamic Motion Sensor (TSS DMS-05). HYPACK version 14.0.9.47, a marine surveying, positioning, and navigation software package, managed the planned-transect information and provided real-time navigation, steering, correction, data quality, and instrumentation-status information to the boat operator. Depth soundings were recorded at 50-ms intervals using an Odom echotrac CV100 sounder with a 200-kilohertz (kHz) transducer. Data from the GPS receiver, motion sensor, and fathometer were recorded in real-time and merged into a single raw data file (.raw) in HYPACK, with each device string referenced by a device identification code and time stamped to UTC. Sound velocity profile (SVP) measurements were collected using a SonTek Castaway Conductivity, Temperature, and Depth (CTD) instrument. The instrument was periodically cast overboard to observe changes in water column speed of sound (SOS). The recorded profiles were later incorporated during post-processing to correct the depth for temporal and spatial SOS changes throughout the water column. Process_Date: 2014 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Swath Bathymetry Acquisition: The interferometric swath bathymetry data were collected aboard the R/V Sallenger in July 2014 and the R/V Tommy Munro in August 2014, using the SEA SWATHplus-H 468 kHz interferometric sonar system. The system was fastened to a static pole mount with the sonar transducer in line with the Novatel GPS antennas sitting atop the mount. Boat position and motion data were recorded in real-time using a CodaOctopus F190R wetpod inertial measurement unit (IMU) mounted underwater, between the transducer heads, to minimize lever arm geometry errors between the observed depths and associated vessel motion. Real-time corrected positions were acquired via Marinestar HP (High-Precision differential global navigation satellite system) differential subscription service from Fugro, Inc. Marinestar HP position correction data and motion data from the IMU were integrated with interferometric soundings in the SWATHplus software version 3.10.2.0 with positional and calibration offsets pre-defined by a session file (.sxs), allowing for real-time-corrected depths. Before deployment, all equipment offsets were measured. During the survey, all swath tracklines were recorded in SWATHplus raw data format (.sxr). A Valeport Mini Sound Velocity Sensor (miniSVS) was attached to the transducer mount and collected continuous SOS measurements at the depth of the transducers. These values were directly read and incorporated into the SWATHplus raw data format during acquisition providing a real-time speed of sound measurement at the transducer, while underway. In addition, a separate Mini Sound Velocity Profiler (Valeport miniSVP) was used to collect speed of sound profiles (water surface to seafloor) at intervals throughout the survey. Process_Date: 2014 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Differentially Corrected Navigation Processing: The coordinate values of the GPS base station (BRET and BRT2) are the time-weighted average of values obtained from the National Geodetic Survey On-Line Positioning User Service (OPUS). The base station coordinates were imported into GrafNav version 8.5 (Waypoint Product Group) and the kinematic GPS data from the survey vessel were post-processed to the concurrent GPS session data at the base stations. During processing, steps were taken to ensure that the trajectories between the base and rover were clean, resulting in fixed positions. By analyzing the graphs, trajectory maps, and processing logs that GrafNav produces for each GPS session, GPS data from satellites flagged by the program as having poor health or satellite time segments that had cycle slips could be excluded, or the satellite elevation mask angle could be adjusted to improve the position solutions. The final, differentially corrected, precise DGPS positions were computed at the respective time intervals of the roving GPS (1.0 s and 0.10 s) and exported in ASCII text format to replace the uncorrected rover positions, recorded during acquisition. The GPS data were processed and exported in the World Geodetic System of 1984 (WGS84)(G1150) geodetic datum. Process_Date: 2014 Source_Produced_Citation_Abbreviation: Post-processed differential navigation data for the rover (boat), in ASCII text format. Three files (forward, reverse, and combined trajectories) are produced for each GPS session file. Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Single-Beam Bathymetry Processing: All data were processed using CARIS HIPS and SIPS (Hydrographic Information Processing System and Sonar Information Processing System) version 8.1.7. The raw HYPACK (version 13.0.9.17 for 14BIM03 and 14.0.9.47 for 14BIM02) 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; ellipsoid height is presented in meters. An in house naming convention for the source files used and source files produced in this process step contain the symbols “xxx” which is a placeholder for a the naming schema. Source_Used_Citation_Abbreviation: Post-processed differential navigation data and raw HYPACK bathymetric data in ASCII text format. Process_Date: 2014 Source_Produced_Citation_Abbreviation: 14BIM02_SBB_ITRF00_03_xxx.txt and 14BIM03_SBB_ITRF00_03_xxx.txt Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Swath Bathymetry Processing: The interferometric swath bathymetry data were collected aboard the R/V Sallenger and the R/V Tommy Munro using a 468 kHz Systems Engineering and Assessment Ltd. (SEA), SWATHplus-H (high frequency) interferometric sonar system. SWATHplus serves as both an acquisition software and initial processing software package. Preliminary roll calibration trackline data were collected and processed using SEA SWATHplus version 3.10.2.0 and Grid Processor software version 3.10.0.0. Instrument offsets and calibration values were input into the session file (.sxs), and the raw data files (.sxr) were then processed using the updated system configuration containing roll calibration values, measured equipment offsets, acquisition parameters, navigation and motion from the F190R, SOS at the sonar head, and SVP cast data. Any calibration offsets and acoustic filtering utilized in SWATHplus is then applied to each raw data file to create a processed data file (.sxp), which was then imported into advanced sounding data processing software CARIS HIPS and SIPS® version 8.1. The initial real-time processing datum for the swath and backscatter data was ITRF05, which is the acquisition datum for Marinestar HP position and navigation data. All processed data files (.sxp) were imported into CARIS HIPS and SIPS® version 8.1. Outliers for the navigation data and processed soundings were removed using program filters. Any remaining data outliers were then edited out manually. A CARIS Bathymetry with Associated Statistical Error (BASE) surface with associated Combined Uncertainty and Bathymetry Estimator (CUBE) sample surface was created from the edited soundings. A CUBE hypothesis is the estimated value of a grid node representing all the soundings within a chosen resolution or grid-cell size (for example, 5 m) weighted by uncertainty and proximity, giving the final value as a "sample" of the data within the specific grid cell. This algorithm allows for multiple grid-node hypotheses to be verified or overridden by the user while maximizing processing efficiency. A 5-m resolution CUBE surface was created to perform initial hypothesis editing using the CARIS Subset Editor tool, followed by higher resolution surface detail editing within subset editor. The sample x,y,z data were exported as an ASCII text file, at a 5-m x 5-m sample resolution in the ellipsoid datum of ITRF05. The data were then transformed into NAD83 and NAVD88 (GEOID09) using VDatum version 3.2. Process_Date: 2014 Source_Produced_Citation_Abbreviation: 14BIM01_IFB_04_5m_ITRF05.txt and 14BIM05_IFB_04_5m_ITRF05.txt Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Datum Transformation: Using the transformation software VDatum version 3.2, the interferometric swath bathymetric data were transformed horizontally from their data acquisition datum (ITRF05 for the IFB and ITRF00 for the SBB) to the North American Datum of 1983 (NAD83) reference frame using the National Geodetic Survey (NGS) geoid model of 2009 (GEOID09). An in-house naming convention for the source files used and source files produced in this process step contain the symbols “xxx” which is a placeholder for a the naming schema. Source_Used_Citation_Abbreviation: 14BIM01_IFB_LEVEL_04_XXX_ITRF05.txt 14BIM02_SBB_Level_03_xxx_ITRF00.txt 14BIM03_SBB_Level_03_xxx_ITRF00.txt 14BIM05_IFB_Level_04_xxx_ITRF05.txt Process_Date: 2014 Source_Produced_Citation_Abbreviation: 14BIM01_IFB_04_5m_NAD83_NAVD88_GEOID09.txt 14BIM02_SBB_04_NAD83_NAVD88_GEOID09.txt 14BIM03_SBB_04_NAD83_NAVD88_GEOID09.txt 14BIM05_IFB_04_5m_NAD83_NAVD88_GEOID09.txt Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Gridding Bathymetric Data: An encompassing digital elevation model (DEM) was created using the soundings from the individual platforms (R/V Sallenger--IFB, R/V Tommy Munro--IFB, R/V Jabba Jaw--SBB, and R/V Chum Bucket--SBB) and lidar data collected in 2014. A running mean of 2 m was applied to each dataset using the open-source software package, Generic Mapping Tools (GMT), version 4.5 blockmean filter to avoid aliasing short wavelengths (Wessel and others 1994). Since the shallow water data collected by the jet skis overlapped the water depth measurements from the topobathy lidar survey, the two data files were merged, and a blockmean filter was applied to the merged data. The data was first sorted by geographic position so that the blockmean filter would prioritize by position rather than acquisition platform. The resulting data file was then gridded into 100 m grid cells, using the GMT Tools surface algorithm with a search radius of 200 m to initialize the grid, and a tension filter of 0.03 to suppress spurious oscillations. A grid mask generated from a polygon digitized around the survey area was applied to the resulting grid to exclude areas of "no data", using the GMT Tools grdmask and grdmath functions. The grid file in Network Common Data Form (NetCDF) was converted to a raster using Esri’s ArcMap version 10.2.2 Multidimension Tool "Make NetCDF Raster Layer" and exported as a GeoTIFF. Additionally, the DEM was converted into a point file using Esri’s raster to point conversion tool and the easting and northing positions populated using XTools Pro version 11.1. The elevation range for the 2014 Breton Island DEM is +1.53 meters to -10.45 m. Source_Used_Citation_Abbreviation: The text files below were used to create the final grid file. The use of "sort" in the file name indicates that the dataset was sorted by position. The "bm2" identifier indicates that the dataset was sent through the Generic Mapping Tools (GMT) version 4.5 blockmean filter. 14BIM_jet_lidar_sort_bm2.txt 14BIM01_Sal_ifb_bm2.txt 14BIM02_twin_sbb_bm2.txt 14BIM03_jet_sbb_bm2.txt 14BIM05_Munro_ifb_bm2.txt 14LGC_lidar_bm2.txt Process_Date: 2015 Source_Produced_Citation_Abbreviation: Breton2014_IFB_SBB_10m_NAD83_NAVD88_GEOID09_DEM.tif Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20201013 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 247 Column_Count: 277 Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 16 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -87.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 100 Ordinate_Resolution: 100 Planar_Distance_Units: meter Geodetic_Model: Horizontal_Datum_Name: D North American 1983 Ellipsoid_Name: GRS 1980 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: North American Vertical Datum 1988 (NAVD88) Depth_Resolution: 0.001 Depth_Distance_Units: meter Depth_Encoding_Method: Implicit coordinate Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Resource_Description: Downloadable data Distribution_Liability: This publication was prepared by an agency of the United States Government. Although these data have been 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF File_Decompression_Technique: ZIP Transfer_Size: 12.9 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://pubs.usgs.gov/ds/1005/downloads/raster/Breton_2014_DEM.zip Fees: none Technical_Prerequisites: The raster contained in the .zip file is available as a GeoTIFF. To utilize this data, the user must have a GIS software package capable of reading the .tif format. Metadata_Reference_Information: Metadata_Date: 20201013 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: 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. Metadata_Security_Information: Metadata_Security_Classification_System: None Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: None