H11618, NOS Hydrographic Survey in the vicinity of Mississippi Sound, Mississippi (2007)

The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation

for safe navigation and to provide background data for engineers, scientific, and other commercial and industrial activities. Hydrographic survey data

primarily consist of water depths, but may also include features (e.g. rocks, wrecks), navigation aids, shoreline identification, and bottom type information.

NOAA is responsible for archiving and distributing the source data as described in this metadata record.

This data set is located in the Mississippi Sound, between Long Beach and Biloxi. The date of collection was June 14, 2006 - March 18, 2007. The

vessels used to collect this data were the High Roller, Hydro Surveyor, and Inland Surveyor. Soundings were collected by an Odom Hydrotrac

Echosounder. The data were originally collected in meters, referenced to MLLW. The data were later converted to feet. The tidal data were processed

using the 1983-2001 epoch.

The NOAA Office for Coastal Management (OCM) downloaded the depth data for this survey from the NGDC website (http://www.ngdc.noaa.gov/mgg/bathymetry/hydro.html)

as x,y,z points. The points were converted from MLLW depths to NAVD88 depths (using grid LAmobile02_8301;Louisiana/Mississippi - Eastern Louisiana to

Mississippi Sound, Version 02 (1983-2001);0;1983-2001) using NOAA's Vertical Datum Transformation tool, VDatum (http://vdatum.noaa.gov/). The NAVD88 depths

were then converted to ellipsoid depths (using the Geoid12a model), converted from x,y,z format to las format and classified as 11 (OCM bathymetry). Finally,

the las files were zipped to laz format.

Original contact information:

Contact Org:

United States Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Environmental Satellite, Data,

and Information Service (NESDIS), National Geophysical Data Center (NGDC)

Title:

United States Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Environmental

Satellite, Data, and Information Service (NESDIS), National Geophysical Data Center (NGDC), National Ocean Service Hydrographic Database Manager

Phone: 303-497-6390

Email: Hydro.Info@noaa.gov

These hydrographic data are made available to the public for a wide variety of uses, such as sea-bottom characterization, habitat classification,

coastal studies, boundary issues, and tsunami forecasting. These data are not intended to be used for navigation. Nautical charts produced and

certified by NOAA should be used for navigation purposes.

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For additional information about this survey, please see the Descriptive Report which may be accessed at:

ftp://ftp.ngdc.noaa.gov/pub/coast/H10001-H12000/H11618/DR/H11618.pdf

A footprint of the surveyed area may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2476/supplemental/h11618.kmz

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA NGDC, the Office for Coastal Management or its partners. These data are not intended to be used for navigation. Nautical charts produced and certified by NOAA should be used for

navigation purposes.

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2476

This data set is dynamically generated based on user-specified parameters.

;

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Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no

longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its

limitations. These data are not intended to be used for navigation. Nautical charts produced and certified by NOAA should be used for

navigation purposes.

This survey follows the coast in an east-west direction. The survey lines were drawn in an east-west direction throughout the survey.

The line spacing was set at 70 meters based on the criteria of 100 percent side scan coverage. The side scan sonar was operated at 75 meter

per channel range depending upon the line spacing in use. Investigation lines where typically collected at 50-meter range. Some lines in depths

of 10 feet or less were run at 75 meter range and some areas were questionable as to whether data could be discerned across the entire swath.

For additional information, please see the Descriptive Report for this survey at:

ftp://ftp.ngdc.noaa.gov/pub/coast/H10001-H12000/H11618/DR/H11618.pdf

In order to verify that the single beam was working properly, lead lines were conducted frequently. Pole measured depths were taken simultaneously with

single beam collection. The results were compared, and if needed, the single beam was corrected.

Sheet C (H11618) adjoins with Sheet B (H11617) and Sheet D (H11619). The junction between Sheets B and C was evaluated and the soundings were found to

agree to within 1 foot. The junction between Sheets C and D was evaluated and the soundings were found to agree to within 1 foot.

Tide and water level corrections were determined and applied in accordance with Attachment #7 of the Statement of Work. Data from the Gulfport Harbor

(8745557) tidal station was used. Tidal zoning as set forth in the Statement of Work was applied. Tidal data were processed using the 1983-01 epoch.

A table showing the tidal zone and correctors that were used for this sheet may be accessed at:

ftp://ftp.ngdc.noaa.gov/pub/coast/H10001-H12000/H11618/TIDES/H11618.tz.pdf

For additional information, please see the Descriptive Report for this survey at:

ftp://ftp.ngdc.noaa.gov/pub/coast/H10001-H12000/H11618/DR/H11618.pdf