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Mobile, Alabama Coastal Digital Elevation Model

browse graphicPerspective view of DEM
NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico. These integrated bathymetric-topographic DEMs were developed for NOAA Coast Survey Development Laboratory (CSDL) through the American Recovery and Reinvestment Act (ARRA) of 2009 to evaluate the utility of the Vertical Datum Transformation tool (VDatum), developed jointly by NOAA's Office of Coast Survey (OCS), National Geodetic Survey (NGS), and Center for Operational Oceanographic Products and Services (CO-OPS). Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. Coastal Services Center (CSC), the U.S. Office of Coast Survey (OCS), the U.S. Army Corps of Engineers (USACE), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of North American Vertical Datum of 1988 (NAVD 88) or Mean High Water (MHW) and horizontal datum of North American Datum of 1983 (NAD 83). Cell size ranges from 1/3 arc-second (~10 meters) to 1 arc-second (~30 meters). The NOAA VDatum DEM Project was funded by the American Recovery and Reinvestment Act (ARRA) of 2009 (http://www.recovery.gov/).

Cite this dataset when used as a source.

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Distribution Formats
  • ESRI Arc ASCII (Version: 1)
    • File Compression: WINZIP
  • netCDF (Version: 3.6.2)
    • File Compression: WINZIP
Distributor DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Point of Contact DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
dem.info@noaa.gov
General Documentation
Associated Resources
  • NOAA VDatum DEM Project
  • Digital Elevation Models of Mobile, Alabama: Procedures, Data Sources, and Analysis
Originator
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publisher
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Date(s)
  • publication: 2009-12-01
Edition: First
Data Presentation Form: mapDigital
Dataset Progress Status Complete
Data Update Frequency: As needed
Purpose: Developed for the Office of Coast Survey (OCS), NOAA Coast Survey Development Laboratory (CSDL) in support of NOAA's Vertical Datum Transformation tool (VDatum).
Use Limitations
  • Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series.
  • Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.
  • While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Time Period: 1888-01-01  to  2009-01-01
Spatial Reference System: urn:ogc:def:datum:EPSG::5868
Spatial Bounding Box Coordinates:
N: 31.00
S: 30.00
E: -87.65
W: -88.30
Spatial Coverage Map:
Themes
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Water Depth
  • Earth Science > Land Surface > Topography > Terrain Elevation
  • Earth Science > Land Surface > Topography > Topographical Relief
  • Earth Science > Oceans > Coastal Processes > Coastal Elevation
  • DEM > Digital Elevation Model
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • WDC/MGG, BOULDER > World Data Center for Marine Geology and Geophysics, Boulder
  • H: 1 meter - < 30 meters
  • V: < 1 meter
  • Coastal Relief
  • Gridded elevations
  • Integrated bathymetry and topography
  • DATA ANALYSIS AND VISUALIZATION > GEOGRAPHIC INFORMATION SYSTEMS > WEB-BASED GEOGRAPHIC INFORMATION SYSTEMS
  • DATA MANAGEMENT/DATA HANDLING > DATA SEARCH AND RETRIEVAL
  • DATA ANALYSIS AND VISUALIZATION > VISUALIZATION/IMAGE PROCESSING
  • DATA ANALYSIS AND VISUALIZATION > GEOGRAPHIC INFORMATION SYSTEMS > WEB-BASED GEOGRAPHIC INFORMATION SYSTEMS
  • DATA MANAGEMENT/DATA HANDLING > DATA SEARCH AND RETRIEVAL
  • DATA ANALYSIS AND VISUALIZATION > VISUALIZATION/IMAGE PROCESSING
Places
  • Continent > North America > United States of America > Alabama
  • Ocean > Atlantic Ocean > Gulf of Mexico
  • Vertical Location > Land Surface
  • Vertical Location > Sea Floor
  • Mobile
  • Mobile County
  • Baldwin County
  • Southern Alabama
Use Constraints No constraint information available
Fees Fee information not available.
Source Datasets
  • NOS Hydrographic Surveys
  • USACE Hydrographic Surveys
  • Little Lagoon Side Scan Sonar Surveys
  • NOAA Coastal Services Center Coastal Bathymetric-Topographic Lidar
  • Composite Shoreline and associated data of Alabama State Composite, AL_COMP
  • Mobile County topographic lidar
    • Description of Source: Source Contribution: topographic lidar ; Source Type: digital files via FTP
    • Temporal extent used:  unknown  to 
  • Baldwin County topographic lidar
    • Description of Source: Source Contribution: topographic lidar ; Source Type: digital files via FTP
    • Temporal extent used:  unknown  to 
  • Shuttle Radar Topography Mission (SRTM)
Lineage Statement Lineage statement not available.
Processor
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Processing Steps
  • All datasets obtained by NGDC were converted to common horizontal and vertical datums of NAD 83 geographic and NAVD 88, respectively, using FME and VDatum transformation tool. They were also converted to common file format, ESRI point shapefiles, for visualization and inspection.
  • Datasets were visually inspected with ArcGIS for identification and editing of data anomalies. Datasets were then compared with overlapping datasets to ensure data consistency.
  • Coastline datasets were merged and adjusted to fit satellite imagery.
  • xyz files of the bathymetric data were surfaced using GMT's 'surface' tool onto a 1 arc-second grid outside Mobile Bay and 1/3 arc-second within the bay that interpolated to fill empty cells. Points extracted every 10 meters along the coastline were also included to ensure that the bathymetric grid reached zero at the coast. The resulting Arc ASCII grid was imported into ArcGIS and clipped to the coastline to remove values over land.
  • xyz files for each input dataset were gridded using MB-System's 'mbgrid' tool, which utilizes a high-tension spline interpolation method to fill grid cells with no input elevation values. Preferential weighting was given to more recent, higher-accuracy datasets. Gridding was performed in quadrants, each with a 5% data buffer. The grids were imported in ArcGIS and seamlessly merged to create the final DEM.
  • The NAVD 88 DEM was quantitatively evaluated by comparing with source datasets and with elevation values extracted from NGS geodetic monuments. It was visually evaluated by converting to UTM-zone coordinates (units of meters horizontally and vertically) and then creating a slope grid to identify gridding artifacts in the DEM.
  • A conversion grid that models the relationship between NAVD 88 and MHW was created using data points and the VDatum transformation tool. This conversion grid was added to the NAVD 88 DEM to generate the MHW DEM.
Processing Environment Native Dataset Environment: Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog 9.3.1.3000

Metadata Last Modified: 2012-12-21

For questions about the information on this page, please email: Matthew.Love@noaa.gov