Identification_Information: Citation: Citation_Information: Originator: Noreen A. Buster Originator: Owen T. Brenner Originator: James G. Flocks Publication_Date: 20171121 Title: Coastal bathymetry data collected between 2008 and 2009 offshore of the Mississippi and Alabama barrier islands: Processed elevation point data Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: U.S. Geological Survey Data Release Issue_Identification: doi:10.5066/F7028QFV Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/F7028QFV Description: Abstract: During the summers of 2008 and 2009 the United States Geological Survey (USGS) conducted bathymetric surveys from West Ship Island, Mississippi, to Dauphin Island, Alabama, as part of the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project. The survey area extended from the shoreline out to approximately two kilometers and included the adjacent passes. These findings were originally published in Dewitt and others (2012). This USGS data release includes updated elevation point data (xyz) in which NOAA's Vdatum version 3.6 was used convert the 2008-2009 XYZ soundings to Universal Transverse Mercator (UTM) North American Datum of 1983 (NAD83) horizontal datum and North American Vertical Datum of 1988 (NAVD88) GEOID12B vertical datum. One goal of this work was to create time-series of bathymetric change maps around the islands using data collected between 1916 to 1920, 2008 to 2009, and in 2016. Purpose: The purpose of this effort was to use available USGS data to create bathymetric grids and bathymetric change maps around the MS barrier islands to broadly characterize subaqueous morphologic change both spatially and temporally. Supplemental_Information: Single-beam bathymetry (SBB) and interferometric swath bathymetry (IFB) elevation data from surveys in July 2008 and June 2009 were merged into one dataset and published in Dewitt and others (2012) (https://pubs.usgs.gov/ds/675). For this data release, NOAA's Vdatum version 3.6 was used convert the 2008-2009 XYZ soundings to Universal Transverse Mercator (UTM) North American Datum of 1983 (NAD83) horizontal datum and North American Vertical Datum of 1988 (NAVD88) GEOID12B vertical datum. These XYZ point values are used to map coastal bathymetry and create bathymetric changes maps for the area within Esri ArcGIS (version 10.4.1). Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20080708 Ending_Date: 20090701 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -89.001529 East_Bounding_Coordinate: -88.386890 North_Bounding_Coordinate: 30.271570 South_Bounding_Coordinate: 30.172387 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: elevation Theme_Keyword: location Theme_Keyword: geoscientificInformation Theme_Keyword: imageryBaseMapsEarthCover Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: marine geology Theme_Keyword: geophysics Theme_Keyword: bathymetry Theme_Keyword: ocean characteristics Theme_Keyword: ocean processes Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: swath sonar Theme_Keyword: hydrography Theme_Keyword: geophysical Theme_Keyword: seafloor mapping Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: Gulf Islands National Seashore (GUIS) Theme_Keyword: SEA Ltd. Theme_Keyword: Systems Engineering and Assessment Theme_Keyword: SWATHplus interferometric Theme_Keyword: SWATHplus Interferometric Swath System Theme_Keyword: SWATHplus -H 468-kHz Interferometric system Theme_Keyword: CMGP Theme_Keyword: St. Petersburg Coastal and Marine Science Center Theme_Keyword: SPCMSC Theme_Keyword: coastal location Theme_Keyword: singlebeam sonar Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Mississippi Place_Keyword: Ship Island Place_Keyword: Horn Island Place_Keyword: Horn Island Pass Place_Keyword: Camille Cut Place_Keyword: Dog Keys Pass Place_Keyword: Petit Bois Island Place_Keyword: Petit Bois Pass Place_Keyword: Little Dog Keys Pass Place_Keyword: Camille Cut Place_Keyword: West Ship Island Place_Keyword: East Ship Island Place_Keyword: Dog Keys Stratum: Stratum_Keyword_Thesaurus: Oregon Geospatial Enterprise Office (GEO) Stratum Keyword Stratum_Keyword: sea surface Stratum_Keyword: epipelagic Temporal: Temporal_Keyword_Thesaurus: None Temporal_Keyword: July 2008 Temporal_Keyword: June 2009 Access_Constraints: None Use_Constraints: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Noreen A. Buster Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center 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: nbuster@usgs.gov Data_Set_Credit: U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center Native_Data_Set_Environment: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.1.4959 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The accuracy of the data is determined during data collection. These datasets are from four separate research cruises and are therefore internally consistent. 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, then survey operations commence. Each system has a dedicated computer, and efforts are made to utilize the same equipment and software versions. 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 Ashtch antenna reference point (ARP) were measured and accounted for in post-processing. Bar checks were performed as calibration efforts and accounted for any drift in the Marimatech Echosounder. The Differential Geographic Positioning System (DGPS) information was obtained using post-processing software packages. For the swath bathymetry, offsets between the sonar head and the DGPS antennas were measured and entered into the F190 internal setup program. DGPS is normally provided through the OmniSTAR High Performance wide-area GPS service unless otherwise noted. DGPS is always implemented for navigational accuracy either during acquisition or as a post-processing step. Logical_Consistency_Report: These elevation point datasets were collected on four research cruises over the course of 21 days for 2008 and 20 days for 2009. This dataset was created to show the combination bathymetry and topography from the cruises. It is a combination of single beam and swath bathymetry and shoreline topography from USGS cruises 08CCT01, 08CCT02, 09CCT03, and 09CCT04. These data provide a continuous and complete surface; however, there may in some cases be data missing and inconsistencies due to the exclusion of poor data and (or) instrument failures. Completeness_Report: This is a complete processed bathymetry and shoreline topography surface in GeoTIFF format. It is a combination of single beam, swath bathymetry, and shoreline topography from USGS cruises 08CCT01, 08CCT02, 09CCT03, and 09CCT04. These data provide a continuous and complete surface; however, there may in some cases be data missing and inconsistent with reported tracklines. This is directly due to the exclusion of poor data and (or) instrument failures. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: GPS base stations were erected within approximately 15 to 20 km of the survey area. Efforts were made to utilize pre-existing National Geodetic Survey (NGS) benchmarks on the islands. If pre-existing benchmarks were unavailable a USGS benchmark was installed. All static base station sessions were run 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 input into a spreadsheet to conduct error analysis and averaging, and any outliers were removed. For the 2008-2009 base station occupations, results were considered sufficient when +/- 3.3 cm or less accuracy in the vertical component was achieved. These base station positions, once finalized, were used for processing. GPS was recorded using Ashtech Z-Xtreme GPS receivers that record the 12-channel full-carrier-phase positioning signals (L1/L2) from the satellites via the Thales choke-ring antenna. This GPS instrument combination is duplicated on the survey vessel (rover). The base receiver and the rover receiver record their positions concurrently at 1-second (s) recording intervals throughout the survey period. The differential navigation for the single beam bathymetry and the swath bathymetry were both collected in the same manner. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 0.00001 Horizontal_Positional_Accuracy_Explanation: decimal seconds Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 0.00000 - 0.00091 Horizontal_Positional_Accuracy_Explanation: decimal seconds Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Ship motion was measured using the CodaOctopus F190 Precision Attitude and Positioning System. The interferometric sonar is an angle-measuring system; depth accuracy decreases with increasing horizontal range. The swath width of the interferometric sonar varied as a function of depth but generally achieved 5 times the water depth. Vertical accuracy is directly affected by the accuracy of both the navigation system and the sonar system. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: -3.3 - + 3.3 Vertical_Positional_Accuracy_Explanation: centimeters Lineage: Process_Step: Process_Description: Process_Description: Acquisition: The single beam data for 2008 were collected using SANDS, which has two components, data acquisition and data processing. The 2008 and 2009 swath bathymetry was collected using the Systems Engineering and Assessment Ltd. (SEA) SWATHplus-H 468 kHz Interferometric System providing both data acquisition and data processing components. The walking kinematic survey of the shoreline was completed using a portable push buggy. Process_Date: 2008 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: US Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Differentially Corrected Navigation Processing: Each base station GPS file was processed to the respective roving survey platform GPS file using GrafNav version 8.10, a product of Waypoint Product Group. During this process, steps were taken to ensure that the trajectory produced from the base to the rover was clean and produced fixed positions. From these processes a single differentially corrected, precise position at 1-s intervals for each roving GPS session was created Process_Date: 2008 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: US Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Single Beam Processing: The external navigation files are combined with the raw trackline soundings in SANDS version 3.92. The raw data are geometrically corrected, and GEOID09 was applied. The exported XYZ data are referenced to NAD83 geodetic datum and NAVD88 (orthometric height), derived using the GEOID12B model. Process_Date: 2008 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: US Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Swath Post-Processing 2008: The raw swath files, (SXR) were run through SWATHplus version 3.06.04.03. The external differential navigation file was substituted for the F190 navigation string; however, the motion (heave, roll, pitch) from the F190 was applied and depths were geometrically corrected. The processed swath files (SXP) were referenced to NAD83, UTM ZONE 16N NAVD88. The SXP files were imported into CARIS HIPS and SIPS version 7.0 with the respective vessel files and merged. Each line was viewed and cleaned in Swath Editor. The filters applied included depth, beam to beam slopes, across-track distance, and missing neighbors. The files were remerged after any changes occurred during the editing process, a 5-m BASE surface was created, and the XYZ data were exported in ASCII format and referenced in NAD83, UTM ZONE 16N NAVD88. Process_Date: 2008 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Contact_Person: Nancy T. DeWitt Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: US Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: ndewitt@usgs.gov Process_Step: Process_Description: Swath Post-Processing 2009: The SXRs were run through SWATHplus version 3.06.0 without inserting the differential external navigation file. The processed SXP data were imported into CARIS HIPS and SIPS version 6.1. The external navigation files were first smoothed in Matlab version R2007b. The external navigation files were then imported into CARIS with the heave correction (waterline height) offset in the respective vessel file and the navigation data applied as a tide file in CARIS during the merge process. Each line was viewed and cleaned in Swath Editor. The filters applied included depth, beam to beam slopes, across-track distance, and missing neighbors. The files were remerged after any changes occurred during the editing process, a 5-m BASE surface was created, and the XYZ data were exported in ASCII format and referenced to NAD83, UTM ZONE 16N, NAVD88 GEOID09. Process_Date: 2009 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - Woods Hole Coastal and Marine Science Contact_Person: Elizabeth A. Pendleton Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: US Contact_Voice_Telephone: 508-457-2259 Contact_Electronic_Mail_Address: ependleton@usgs.gov Process_Step: Process_Description: Using Vdatum (version 3.6.1) the vertical reference datum of the XYZ point data was converted from NAVD88 GEOID09 to NAVD88 GEOID12B. Vdatum reports vertical uncertainty associated with this transformation as 10.198 centimeters. Process_Date: 2017 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Contact_Person: Noreen A. Buster Contact_Position: Geologist Contact_Address: Address_Type: mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: US Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: nbuster@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 1048575 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: 0.999600 Longitude_of_Central_Meridian: -87.000000 Latitude_of_Projection_Origin: 0.000000 False_Easting: 500000.000000 False_Northing: 0.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.6096 Ordinate_Resolution: 0.6096 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum 1988 Altitude_Resolution: 0.0001 Altitude_Distance_Units: meters Altitude_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: 2008_2009_MS_NAD83NAVD88g12B.txt Entity_Type_Definition: Tab-delimited text file containing the processed 1-meter resolution swath and single-beam bathymetry XYZ samples transformed to the NAD83 geodetic datum and NAVD88 (orthometric height), derived using the GEOID12B model. Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: X_NAD83 Attribute_Definition: NAD83 UTM zone 16N X-coordinate (easting) of sample point, in meters Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 307450.000 Range_Domain_Maximum: 373273.640 Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: Y_NAD83 Attribute_Definition: NAD83 UTM zone 16N Y-coordinate (northing) of sample point, in meters Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3339576.760 Range_Domain_Maximum: 3349693.666 Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: NAVD88g12B Attribute_Definition: NAVD88 (orthometric height) of sample point, in meters with respect to GEOID12B. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 13.313 Range_Domain_Maximum: 0 Attribute_Measurement_Resolution: 0.0001 Attribute: Attribute_Label: Year Attribute_Definition: Year data were collected Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2008 Range_Domain_Maximum: 2009 Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Noreen A. Buster Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center 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) 502-8114 Contact_Electronic_Mail_Address: nbuster@usgs.gov Resource_Description: 2008_2009_MS_NAD83NAVD8812B_XYZ.txt Distribution_Liability: Although these data have been processed successfully on a computer system at 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. The USGS shall not be held liable for improper or incorrect use of the data described or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 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Buster Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center 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: nbuster@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Security_Information: Metadata_Security_Classification_System: none Metadata_Security_Classification: unclassified Metadata_Security_Handling_Description: None