Each line used to produce this grid has been reviewed and edited to remove inaccurate soundings.
This grid does not include all bathymetric data collected within the Barnegat Bay Survey area. Data collected along some transit lines, and seismic-reflection tie lines were excluded from this grid. The "Grid" attribute in BarnBayBathTrks.shp (
http://pubs.usgs.gov/ds/0937/downloads/shapefile/BarnBayBathTrks.zip) record the lines used to generate this grid.
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Two different navigation systems (DGPS and RTK) were used to record horizontal positions of the bathymetric sonar.
2011-041-FA and 2013-014-FA: Differential Global Positioning System (DGPS) navigation was used to determine the horizontal position (x, and y coordinates) of the GPS antenna mounted above the SWATHplus-H transducers with sub-meter accuracy. A motion reference unit (Coda Octopus F180) was mounted directly above the sonar transducers and continuously measured vertical displacement (heave) and attitude (pitch and roll) of the vessel during data acquisition. Horizontal offsets between navigation and attitude antennas and the SWATHplus-H transducers were recorded and applied during acquisition in the configuration files for the Swath Processer and Coda Octopus software. Differential corrections were obtained real-time via the Wide Area Augmentation System (WAAS) providing horizontal accuracy of 1-2 meters.
2012-003-FA and 2013-030-FA Real Time Kinematic (RTK) navigation was used to determine the horizontal position (x, and y coordinates) of the GPS antenna mounted above the SWATHplus-H transducers with sub-meter accuracy. A RTK-enabled motion reference unit (Coda Octopus F190) was mounted directly above the sonar transducers and continuously measured vertical displacement (heave) and attitude (pitch and roll) of the vessel during data acquisition. Horizontal offsets between navigation and attitude antennas and the SWATHplus-H transducers were applied during acquisition in the configuration files for the Swath Processor and Coda Octopus software.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
A motion reference unit was mounted directly above the sonar transducers and continuously measured vertical displacement (heave) and attitude (pitch and roll) of the vessel during data acquisition. A Coda Octopus F180 motion reference unit was used for survey 2011-041-FA and 2013-014-FA. During surveys 2012-003-FA and 2013-030-FA a Coda Octopus F190 was used. Vertical offsets between navigation and attitude antennas and the SWATHplus-H transducers were applied during acquisition in the configuration files for the Swath Processor and Coda Octopus software. Vertical accuracy of the raw data may approximate 1 percent of water depth, based on SWATHplus interferometric sonar system specifications, which translates to 0.1 to 0.23 meters within the Barnegat Bay survey area. Real Time Kinematic (RTK)-GPS was used to continuously measure changes in sea-surface elevations relative to the North American Vertical Datum(NAVD 88) with decimeter-scale accuracies. Tide-correction was applied during post-processing (see process steps). Refraction artifacts were minimized by sound velocity profiles throughout the survey area to model the spatial and temporal variability of sound velocity structure of the water column. Changes in vessel draft due to fuel and water usage were not considered.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2015
Title: raw SWATHPlus sxr files
Geospatial_Data_Presentation_Form: raster digital data
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20111101
Ending_Date: 20130916
Source_Currentness_Reference:
ground condition of individual surveys during bathymetry collection: 20111101-20111107; 20120321-20120408; 20130313-20130326; 20130911-20130916
Source_Citation_Abbreviation: Raw SXR files
Source_Contribution:
SONAR CONFIGURATION: Bathymetry data were acquired using a Systems Engineering and Assessment Ltd (SEA) SWATHplus-H interferometric sonar operating at a frequency of 468 kHz. The sonar transducers were mounted on a rigid pole installed on the bow of the R/V Rafael and was deployed at a depth of 0.7 m below the water line while collecting data. Typical sonar operating parameters include a transmit power of 60%, a transmit length of 34 or 43 cycles, and a sample rate of 4096 samples per channel.
SPEED OF SOUND; sound velocity profiles were collected approximately every two hours, or when water properties changed using a hand-deployed sampler. Sound velocity data within the water column was measured using AML Oceanographic SVP Plus profiler during surveys 2011-041-FA and 2012-003-FA, and an AML Oceanographic MINOS-X profiler during 2013-014 and 2013-030.
TIDES: Soundings were referenced to the North American Vertical Datum of 1988 (NAVD 88) using 1-minute averaged RTK-GPS sea-surface elevation data.
Process_Step:
Process_Description:
Step 1:Process GPS Tides Data for all four surveys:
Depths were corrected to North American Vertical Datum of 1988 (NAVD88)) using the 1 second RTK-GPS heights from the GPS receiver mounted over the SWATHplus-H sonar head. Two scripts were used to extract the navigation and described below:
Script "getNovatelTides": extracts the "TID" record from each Hypack line file "parseHypackNovatelTides.awk": calculates the average TID value for every two minutes. Each day was appended to a master tide file in CARIS format ("SurveyName"Master.tid) and merged into the line files in Processing Step #3 below.
Process_Date: 2013
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 2: Raw to processed conversion for all four surveys.
Each raw SWATHplus bathymetric sonar file (*.sxr) was converted to a SWATHplus processed file (*.sxp) using Swath Processor software (v. 3.07). During the conversion process, sound velocity profiles were applied for the speed of sound within the water column and bathymetric filters were applied.
Process_Date: 2013
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 3: SWATHplus to CARIS HIPS Conversion: A new CARIS HIPS project (v. 7.2) was created for each of the four surveys with projection information set to Universal Transverse Mercator (UTM) Zone 18 North, WGS 84. Each processed file (*.sxp) was imported to the new HIPS project using the import/conversion wizard. The line files for each day were merged with the Mastertide file (SurveyNameMasterTide.tid) to reference each line to NAVD 88. A 2-meter Bathymetric and Statistical Error (BASE) surface was created from the files for each day. The BASE surface for each day was reviewed for an inconsistencies or data anomalies. Navigation was edited as needed using the navigation editor tool in HIPS. Filters were applied to each line including beam-to-beam slopes (1 degree) and an across track distance of 3-4 times water depth. For a nadir depth of 3 meters an across track filter of 3 times water depth would reduce the swath coverage to 9 meters on each side for a total swath coverage of 18 meters.
Process_Date: 20140128
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 4. Surface creation and export to x,y,z.
Survey lines for each Julian Day were reviewed using HIPS Swath Editor, finalized, and added to the surface for each of the four surveys. Data were gridded using a 5-m resolution for input to a continuous terrain model. Output surfaces: 2011_041_5m.csar, 2012_003_5m.csar, 2013_014_5m.csar, 2013_030_5m.csar.
Surfaces were combined in CARIS Base Editor (v. 4.0) using the "combine" tool and "Data Start Date is least" rule for overlapping cells. This rule condition means that earlier surveys have importance over later surveys where they may overlap. Final output surface= BarnBayOFR5m.csar. This surface was then converted to an ascii x,y,z file(USGSBath5m.txt) using the "export surface to ASCII" tool within Base Editor (v. 4.0).
Process_Date: 20140128
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 5: Create terrain model from x,y,z and produce a continuous surface.
A new file geodatabase (BarnBayOFRTer91) was created within ArcGIS (v. 9.1.3); a new feature dataset (BBTerrain) was added and the x,y,z data (USGSBath5m.txt) was imported. Next a Terrain Model (BBTerrainSP) was created using "Create Terrain" tool within ArcToolbox (v. 9.1.3). The "USGSBath5m" feature class was input dataset, and average point spacing of 5 meters was used along with a pyramid type of "ZTolerance".
Process_Date: 20140128
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 6: Add data bounds and build terrain.
A polygon feature class (USGSBnd) that encompassed all the input x,y,z points was created and added to the terrain data set. The terrain was then built using the "Build Terrain" tool within ArcToolbox (v. 9.1.3). The terrain uses a Triangulated Irregular Network (TIN) model to connect points with surfaces and thus filling in the gaps between adjacent survey lines. Finally, the terrain was exported to an Arc raster (bbtgsp10m) using the natural neighbors option in the "Terrain to Raster" and a cell size of 10-m.
Process_Date: 20140128
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description:
Step 7:Changed incorrect data download links in the Online_linkage and Network_Resource_Name sections
Process_Date: 20160706
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Brian Andrews
Contact_Organization: U.S. Geological Survey
Contact_Position: Geographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2348
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: bandrews@usgs.gov
Process_Step:
Process_Description: USGS Thesaurus keywords added to the keyword section.
Process_Date: 20180720
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
Process_Step:
Process_Description: Crossref DOI link was added as the first link in the metadata.
Process_Date: 20191115
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
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20200908
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
