USGS NED ned19_n30x25_w088x75_al_ms_mobilebay_topobathy_2012 1/9 arc-second 2012 15 x 15 minute IMG

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: U.S. Geological Survey

Publication_Date: 2012

Title:

USGS NED ned19_n30x25_w088x75_al_ms_mobilebay_topobathy_2012 1/9 arc-second 2012 15 x 15 minute IMG

Geospatial_Data_Presentation_Form: raster digital data

Publication_Information:

Publication_Place: Reston, VA

Publisher: U.S. Geological Survey

Online_Linkage: <http://ned.usgs.gov/>

Online_Linkage: <http://nationalmap.gov/viewer.html>

Description:

Abstract:

This tile of the National Elevation Dataset (NED) is 1/9 arc-second resolution. The National Elevation Dataset (NED) serves the elevation layer of The National Map, and provides basic elevation information for earth science studies and mapping applications in the United States. Scientists and resource managers use NED data for global change research, hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. The NED is an elevation dataset that consists of seamless layers and a high resolution layer. Each of these layers are composed of the best available raster elevation data of the conterminous United States, Alaska, Hawaii, territorial islands, Mexico and Canada. The NED is updated continually as new data become available. All NED data are in the public domain. The NED are derived from diverse source data that are processed to a common coordinate system and unit of vertical measure. These data are distributed in geographic coordinates in units of decimal degrees, and in conformance with the North American Datum of 1983 (NAD 83). All elevation values are in meters and, over the continental United States, are referenced to the North American Vertical Datum of 1988 (NAVD 88). The vertical reference will vary in other areas. NED data are available nationally (except for Alaska) at resolutions of 1 arc-second (approx. 30 meters) and 1/3 arc-second (approx. 10 meters), and in limited areas at 1/9 arc-second (approx. 3 meters). In most of Alaska, only lower resolution source data are available. As a result, most NED data for Alaska are at 2-arc-second (approx. 60 meters) grid spacing. Part of Alaska is available at the 1- and 1/3-arc-second resolution from IFSAR collections starting in 2010. Plans are in place for collection of statewide IFSAR in Alaska through 2016.

Purpose:

The NED serves as the elevation layer of The National Map, and provides basic elevation information for earth science studies and mapping applications in the United States. The data are utilized by the scientific and resource management communities for global change research, hydrologic modeling, resource monitoring, mapping and visualization applications.

Supplemental_Information:

This tile of the National Elevation Dataset (NED) is 1/9 arc-second resolution, Image file format, and covers a one degree block. The geographic area of coverage is described below in the Bounding Coordinates. Additional information for the NED may be found on <http://ned.usgs.gov/>. Data may be downloaded through The National Map Viewer: <http://nationalmap.gov/viewer.html>. Direct links for direct access by automated services are provided in the Distribution section of this metadata.

Time_Period_of_Content:

Time_Period_Information:

Multiple_Dates/Times:

Single_Date/Time:

Calendar_Date: 2001 - 2011

Time_of_Day: LiDAR Data

Single_Date/Time:

Calendar_Date: 1917 - 2007

Time_of_Day: Bathymetric Data

Currentness_Reference: publication date

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As Needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -88.750185185185217

East_Bounding_Coordinate: -88.49981481481484

North_Bounding_Coordinate: 30.250185185185192

South_Bounding_Coordinate: 29.999814814814822

Keywords:

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme_Keyword: elevation

Theme:

Theme_Keyword_Thesaurus: NGDA Portfolio Themes

Theme_Keyword: Elevation

Theme:

Theme_Keyword_Thesaurus: National Elevation Dataset (NED)

Theme_Keyword: National Elevation Dataset

Theme_Keyword: NED

Theme_Keyword: Elevation

Theme_Keyword: Grid

Theme_Keyword: LIght Detection And Ranging

Theme_Keyword: LIDAR

Theme_Keyword: Interferometric Synthetic Aperture Radar

Theme_Keyword: IFSAR

Theme_Keyword: High Resolution

Theme_Keyword: Topographic Surface

Theme_Keyword: Topography

Theme_Keyword: Bare Earth

Theme_Keyword: Hydro-Flattened

Theme_Keyword: Terrain Elevation

Theme_Keyword: 15-minute DEM

Theme_Keyword: 1/9 arc-second DEM

Theme_Keyword: Cartography

Theme_Keyword: DEM

Theme_Keyword: Digital Elevation Model

Theme_Keyword: Digital Mapping

Theme_Keyword: Digital Terrain Model

Theme_Keyword: Geodata

Theme_Keyword: GIS

Theme_Keyword: Mapping

Theme_Keyword: Raster

Theme_Keyword: USGS

Theme_Keyword: U.S. Geological Survey

Place:

Place_Keyword_Thesaurus: Geographic Names Information System

Place_Keyword: US

Place_Keyword: United States

Access_Constraints:

None. Any downloading and use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer. Insure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests.

Use_Constraints:

There is no guarantee or warranty concerning the accuracy of the data. Users should be aware that temporal changes may have occurred since these data were collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Any user who modifies the data is obligated to describe the types of modifications they perform. User specifically agrees not to misrepresent the data, nor to imply that changes made were approved or endorsed by the USGS. Please refer to <http://www.usgs.gov/privacy.html> for the USGS disclaimer.

Browse_Graphic:

Browse_Graphic_File_Name:

<ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/NED/19/IMG/ned19_n30x25_w088x75_al_ms_mobilebay_topobathy_2012_thumb.jpg>

Browse_Graphic_File_Description: Thumbnail JPG image

Browse_Graphic_File_Type: JPEG

Data_Set_Credit:

Acknowledgement of the originating agencies would be appreciated in products derived from these data.

Data_Quality_Information:

Logical_Consistency_Report:

Please refer to the Metadata Section at the end of this document for a live link to a copy of the original data source's metadata file if one was provided.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

The horizontal accuracy of bathymetric and topographic features in the DEM is dependent upon DEM cell size and the accuracy of input datasets used to determine corresponding cell values.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The absolute vertical accuracy of the merged model ranges between +/- 6 to 20 centimeters for the topographic surface. Quality checks are built into the data-processing software.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2005 Post Hurricane Katrina - Topographic Infrared Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 6 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2010 Baldwin County - Topographic Infrared Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 12.9 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2002 Mobile County - Topographic Infrared Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 13.9 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2011 Baldwin County - Topographic Infrared Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 15 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2001 Baldwin County - Topographic Infrared Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 15 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2007 EAARL - Bathymetric Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 15 cm RMSE

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 2005 CHARTS - Bathymetric Lidar

Vertical_Positional_Accuracy_Explanation: Absolute Vertical Accuracy: 20 cm RMSE

Lineage:

Process_Step:

Process_Description:

USGS NED ned19_n30x25_w088x75_al_ms_mobilebay_topobathy_2012 1/9 arc-second 2012 15 x 15 minute IMG. Topobathymetric data are a merged rendering of both topography (land elevation) and bathymetry (water depth) to provide a seamless elevation product useful for inundation mapping, as well as other earth science applications, such as the development of sediment-transport, sea level rise, and storm surge models. Topo/Bathy Creation Steps: a.) Constructed a high-resolution shoreline for each pilot study area based upon the associated topographic lidar, bathymetry, and aerial photography data. The shoreline was aligned to the North American Vertical Datum of 1988 (NAVD 88) vertical reference frame. b.) Converted tidally-referenced bathymetric data sources into the NAVD88 vertical reference frame using VDatum. VDatum (<http://vdatum.noaa.gov>) is a tool developed by the National Geodetic Survey (NGS) that performs transformations among tidal, ellipsoid-based, geoid-based, and orthometric datums using calibrated hydrodynamic models. Utilized VDatum and other tools to perform any necessary standardization processing on bathymetric source data to confirm proper vertical and horizontal properties are applied. The National Ocean Service (NOS) (<http://oceanservice.noaa.gov/>) hydrographic, multibeam, and trackline surveys were transformed from MLLW and MLLWS to NAVD 88 using VDatum. c.) Performed a quality assurance (Q/A) assessment on the input bathymetry data to review the points for data consistency and spurious anomalies. Prioritized and spatially sorted the bathymetry based on temporal frequency, spatial distribution, accuracy, and point density to eliminate any outdated or erroneous points and to minimize interpolation artifacts. d.) Spatially interpolated bathymetric single-beam, multi-beam, and hydrographic survey source data using an adjustable tension continuous curvature surface gridding algorithm. This algorithm works similarly to that of a thin-plate spline algorithm. For the gridded bathymetry, a smoothing filter (FocalMean) was employed to minimize noise effects and to improve visual characteristics of the data. e.) Performed a quality assurance (Q/A) assessment on the input lidar data to review the point cloud for spurious anomalies and to ensure that the point cloud has been post-processed to bare-earth. Checked the quality of the bare-earth processing to make sure urban built-up and vegetation areas are properly flattened. If the point cloud contains no classification then the lidar data must be processed to bare-earth. f.) Used triangulated irregular networks (TINs) to grid the input lidar source data using breaklines and associated terrain-based features at a 1/9th arc-second spatial resolution using linear interpolation. Extracted from the National Elevation Dataset (NED), all available 1/9th arc-second topographic datasets for the pilot area. g.) Developed an integrated shoreline transition zone from the best available topographic and bathymetric data to blend the topographic and bathymetric elevation sources. Using the high-resolution shoreline, created a buffer to logically mask input topography/bathymetry data. Then, through the use of TINs and breaklines, interpolated the selected topographic and bathymetric points to gap-fill nearshore holes in the bathymetric coverage. Topobathymetric lidar data sources such as the Experimental Advanced Airborne Research Lidar (EAARL) or Compact Hydrographic Airborne Rapid Total Survey (CHARTS) systems provide up-to-date, high-resolution data along the critical land/water interface within inter-tidal zone. h.) Spatially mosaicked the gridded lidar, bathymetric, and integrated shoreline transition zone raster data sources to create a seamless topobathymetric composite at a 1/9th arc-second resolution using a combination of methods such as, "blend" (spatial weighting) and "last input" in the overlapping regions of the mosaic. i.) Generated spatially referenced metadata for each unique data source. The spatially reference metadata consists of a group of geospatial polygons that represent the spatial footprint of each data source used in the generation of the topobathymetric dataset. Each polygon was populated with attributes that describe the source data, such as, acquisition date and source name. Metadata was created for display through The National Map Viewer at <http://nationalmap.gov/viewer.html> in XML format.

Process_Date: 2012

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical address

Address: USGS National Geospatial Program Office

Address: 12201 Sunrise Valley Drive

City: Reston

State_or_Province: VA

Postal_Code: 20192

Country: USA

Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)

Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)

Contact_Instructions: Please visit <http://www.usgs.gov/ask/> to contact us.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Row_Count: 22034

Column_Count: 38029

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.0001

Longitude_Resolution: 0.0001

Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.2572221

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988

Altitude_Resolution: 0.001

Altitude_Distance_Units: meters

Altitude_Encoding_Method: Implicit coordinate

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview: The attribute summary can be found in the data dictionary.

Entity_and_Attribute_Detail_Citation:

A link to the NED Data Dictionary describing information that is included in the spatial metadata shapefiles acquired with the DEM is provided at the end of the Metadata Section of this document.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical

Address: USGS National Geospatial Program Office

Address: 12201 Sunrise Valley Drive

City: Reston

State_or_Province: VA

Postal_Code: 20192

Country: USA

Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)

Hours_of_Service: Monday through Friday 8:00 AM to 4:00 PM Eastern Time Zone USA

Contact_Instructions: Please visit <http://www.usgs.gov/ask/> to contact us.

Resource_Description: Downloadable Data

Distribution_Liability:

Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty, expressed or implied, is made by either regarding the utility of the data on any system, nor shall the act of distribution constitute any such warranty. The USGS will warranty the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer peripherals, or when the physical medium is delivered in damaged condition. Requests for adjustments of credit must be made within 90 days from the date of this shipment from the ordering site.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: IMG

Transfer_Size: 40.206955

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

<ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/NED/19/IMG/ned19_n30x25_w088x75_al_ms_mobilebay_topobathy_2012.zip>

Fees: NONE

Metadata_Reference_Information:

Metadata_Date: 20140212

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical address

Address: USGS National Geospatial Program Office

Address: 12201 Sunrise Valley Drive

City: Reston

State_or_Province: VA

Postal_Code: 20192

Country: USA

Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)

Hours_of_Service: Monday through Friday 8:00 AM to 4:00 PM Eastern Time Zone USA

Contact_Instructions: Please visit <http://www.usgs.gov/ask/> to contact us.

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Extensions:

Online_Linkage: <http://ned.usgs.gov/NED/metadata.asp>

Profile_Name:

National Elevation Dataset (NED) Metadata Data Dictionary Access

Metadata_Extensions:

Online_Linkage:

<http://ned.usgs.gov/source_metadata/AL_MS_orig_topobathy_metadata.xml>

Profile_Name:

Original Data Provider Project Metadata File: Topobathymetric Data for Mobile Bay, Alabama