Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2011 Title: EAARL Topography--Three Mile Creek and Mobile-Tensaw Delta, Alabama, 2010 Edition: first Geospatial_Data_Presentation_Form: remote-sensing image Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: 618 Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/ds/618 Description: Abstract: A digital elevation model (DEM) of a portion of the Mobile-Tensaw Delta region and Three Mile Creek in Alabama was produced from remotely sensed, geographically referenced elevation measurements by the U.S. Geological Survey (USGS). Elevation measurements were collected over the area (bathymetry was irresolvable) using the Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 50 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by the National Aeronautics and Space Administration (NASA) at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of +/-15 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development. For more information on Lidar science and the Experimental Advanced Airborne Research Lidar (EAARL) system and surveys, see http://ngom.usgs.gov/dsp/overview/index.php and http://ngom.usgs.gov/dsp/tech/eaarl/index.php . Purpose: The purpose of this project was to produce highly detailed and accurate digital elevation maps of a portion of the Mobile-Tensaw Delta region and Three Mile Creek in Alabama for use as a management tool for evaluating how water levels, landform structure, and habitat types interact within the survey area, and how changes in the water flow and elevation affect available stream areas, wetlands, and bottom woodland habitat during seasonal formative periods critical to fish and wildlife production. Supplemental_Information: Raw lidar data are not in a format that is generally usable by resource managers and scientists for scientific analysis. Converting dense lidar elevation data into a readily usable format without loss of essential information requires specialized processing. The U.S. Geological Survey's Coastal and Marine Geology Program (CMGP) has developed custom software to convert raw lidar data into a GIS-compatible map product to be provided to GIS specialists, managers, and scientists. The primary tool used in the conversion process is Airborne Lidar Processing System (ALPS), a multi-tiered processing system developed by a USGS-NASA collaborative project. Specialized processing algorithms are used to convert raw waveform lidar data acquired by the EAARL to georeferenced spot (x,y,z) returns for "first surface" and "bare earth" topography. The terms first surface and bare earth refer to the digital elevation data of the terrain, but while the first-surface data include vegetation, buildings, and other manmade structures, the bare-earth data do not. The zero crossing of the second derivative (that is, detection of stationary points) is used to detect the first return, resulting in "first surface" topography, while the trailing edge algorithm (that is, the algorithm searches for the location prior to the last return where direction changes along the trailing edge) is used to detect the range to the last return, or "bare earth" (the first and last returns being the first and last significant measurable portion of the return pulse). Statistical filtering, known as the Random Consensus Filter (RCF), is used to remove false bottom returns and other outliers from the EAARL topography data. The filter uses a grid of non-overlapping square cells (buffer) of user-defined size overlaid onto the original point cloud. The user also defines the vertical tolerance (vertical width) based on the topographic complexity and point-sampling density of the data. The maximum allowable elevation range within a cell is established by this vertical tolerance. An iterative process searches for the maximum concentration of points within the vertical tolerance and removes those points outside of the tolerance (Nayegandhi and others, 2009). These data are then converted to the North American Datum of 1983 and the North American Vertical Datum of 1988 (using the GEOID09 model). Each file contains data located in a 2-kilometer by 2-kilometer tile, where the upper-left bound can be assessed quickly through the filename. The first 3 numbers in the filename represent the left-most UTM easting coordinate (e###000) in meters, the next 4 numbers represent the top-most UTM northing coordinate (n####000) in meters, and the last 2 numbers (##) represent the UTM zone in which the tile is located (for example, fs_e123_n4567_16).The development of custom software for creating these data products has been supported by the U.S. Geological Survey CMGP's Decision Support for Coastal Science and Management project. Processed data products are used by the U.S. Geological Survey CMGP's National Assessments of Coastal Change Hazards project to quantify the vulnerability of shorelines to coastal change hazards such as severe storms, sea-level rise, and shoreline erosion and retreat. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20100306 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -88.174905 East_Bounding_Coordinate: -87.814443 North_Bounding_Coordinate: 31.142602 South_Bounding_Coordinate: 30.694241 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:393e506f-90b3-4a8e-b22c-d2b5332d35bd Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: General Theme_Keyword: Airborne Lidar Processing System Theme_Keyword: ALPS Theme_Keyword: Digital Elevation Model Theme_Keyword: DEM Theme_Keyword: EAARL Theme_Keyword: Experimental Advanced Airborne Research Lidar Theme_Keyword: laser altimetry Theme_Keyword: lidar Theme_Keyword: Pilatus PC-6 Theme_Keyword: remote sensing Theme_Keyword: topography Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: distributions Theme_Keyword: bathymetry and elevation Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) Keywords Theme_Keyword: altimetry Theme_Keyword: topographic mapping Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: LIDAR Theme_Keyword: topography Theme_Keyword: digital elevation models Place: Place_Keyword_Thesaurus: General Place_Keyword: Three Mile Creek Place_Keyword: Mobile-Tensaw Delta Place_Keyword: Alabama Place_Keyword: United States Place_Keyword: North America Stratum: Stratum_Keyword_Thesaurus: General Stratum_Keyword: First Surface/Bare Earth Temporal: Temporal_Keyword_Thesaurus: General Temporal_Keyword: 2010 Access_Constraints: None Use_Constraints: The U.S. Geological Survey requests to be acknowledged as the originator of these data in future products or derivative research. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Amar Nayegandhi Contact_Organization: Jacobs Technology, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Remote Sensing Specialist/Project Manager Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 (x3026) Contact_Facsimile_Telephone: 727 803-2031 Contact_Electronic_Mail_Address: anayegandhi@usgs.gov Hours_of_Service: M-F, 9:00-5:00 EST Browse_Graphic: Browse_Graphic_File_Name: http://pubs.usgs.gov/ds/618/html/images/MTD_be_mosaic.jpg Browse_Graphic_File_Description: EAARL Topography–Three Mile Creek and Mobile-Tensaw Delta, Alabama, 2010 Bare-Earth Mosaics: 2.5-meter resolution Browse_Graphic_File_Type: JPG Browse_Graphic: Browse_Graphic_File_Name: http://pubs.usgs.gov/ds/618/html/images/MTD_fs_mosaic.jpg Browse_Graphic_File_Description: EAARL Topography–Three Mile Creek and Mobile-Tensaw Delta, Alabama, 2010 First-Surface Mosaics: 2.5-meter resolution Browse_Graphic_File_Type: JPG Data_Set_Credit: Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. Security_Information: Security_Classification_System: Unclassified Security_Classification: Unclassified Security_Handling_Description: None Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350 Cross_Reference: Citation_Information: Originator: Nayegandhi, A., Brock, J.C., and Wright, C.W. Publication_Date: 2009 Title: Small footprint, waveform-resolving lidar estimation of submerged and subcanopy topography in coastal environments Series_Information: Series_Name: International Journal of Remote Sensing Issue_Identification: 30(4), p. 861-878 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The expected accuracy of the measured variables is as follows: attitude within 0.07 degree, 3 centimeters nominal ranging accuracy, and vertical elevation accuracy of +/-15 centimeters for the topographic surface. Quality checks are built into the data-processing software. Logical_Consistency_Report: Each file contains data located in a 2-kilometer by 2-kilometer tile where the upper-left bound can be assessed quickly through the filename. The first 3 numbers in the filename represent the left-most UTM easting coordinate (e###000) in meters, the next 4 numbers represent the top-most UTM northing coordinate (n####000) in meters, and the last 2 numbers (##) represent the UTM zone in which the tile is located (for example, fs_e123_n4567_16). Completeness_Report: Several regions of the dataset are labeled as "No Data," which corresponds to a cell value of -32767 meters in the GeoTIFF file. These "No Data" areas are a result of the survey not covering a particular region, optical water depth of greater than 1.5 Secchi disc depths, or the manual removal of lidar processing artifacts. The presence of "No Data" values does not necessarily indicate an absence of land, but rather an absence of survey coverage or the presence of prolific vegetation that the laser is not able to penetrate in order to return bare-earth data. This metadata file is generalized; each data file on this DVD has its own corresponding metadata file. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Raw elevation measurements have been determined to be within 1 meter in horizontal accuracy. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Typical vertical elevation accuracies for these data are consistent with the point elevation data, +/-15 centimeters. However, a ground-control survey is not conducted simultaneously with every lidar survey. Vertical accuracies may vary based on the type of terrain and the accuracy of the GPS and aircraft-attitude measurements. Lineage: Process_Step: Process_Description: The data were collected using a Pilatus PC-6 aircraft. The Experimental Advanced Airborne Research Lidar (EAARL) laser scanner collects the data using a green-wavelength (532-nanometer) raster scanning laser, while a digital camera acquires a visual record of the flight. The data are stored on hard drives and archived at the U.S. Geological Survey office in St. Petersburg, Florida. The navigational data are processed and, along with the raw data, are then downloaded into ALPS, or the Airborne Lidar Processing System (20100306 - 20110121). Data are converted from units of time to x,y,z points for elevation and formatted into .las and .xyz files. The derived surface data can then also be converted into raster data (GeoTIFFs). Process_Date: 20110121 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jamie M. Bonisteel-Cormier Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Lidar Analyst Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 (x3124) Contact_Electronic_Mail_Address: jcormier@usgs.gov Hours_of_Service: M-F, 8:00-4:00 EST Process_Step: Process_Description: Metadata imported into ArcCatalog from XML file. Process_Date: 20110210 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Xan Fredericks Contact_Organization: Jacobs Technology, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: GIS Analyst/Metadata Specialist Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 (x3086) Contact_Electronic_Mail_Address: afredericks@usgs.gov Hours_of_Service: M-F, 8:00-4:00 EST Process_Step: Process_Description: Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Process_Date: 20170124 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Alan O. Allwardt Contact_Position: Contractor -- Information Specialist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7551 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aallwardt@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20201013 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 Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Tiling Index Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Pixel 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 False_Easting: 500000.000000 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 2.500000 Ordinate_Resolution: 2.500000 Planar_Distance_Units: meters 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: 298.25722210100002 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Resolution: 0.15 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Each pixel of the encoded GeoTIFF has an explicit elevation value associated with it. The GeoTIFF grid is encoded with the interpolated elevation value at a 2.5-meter resolution. The input parameters for the random consensus filter (RCF) were grid cell size (buffer) = 6 meters x 6 meters; vertical tolerance (vertical width) = 500 centimeters for Three Mile Creek first surface and 800 centimeters for Mobile-Tensaw Delta first surface; and 50 centimeters for Three Mile Creek bare earth and 40 centimeters for Mobile-Tensaw Delta bare earth. The GeoTIFFs are created using Delauney triangulation, followed by linear interpolation based on routines in the ITT VIS Interactive Data Language (IDL) code. Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/of/2009/1078/ Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Amar Nayegandhi Contact_Position: Remote Sensing Specialist/Project Manager Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 (x3026) Hours_of_Service: M-F, 9:00-5:00 EST Resource_Description: DS 618 Distribution_Liability: This DVD publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, 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 U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, expressed or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: 2 Format_Specification: GeoTIFF Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/ds/618/data_files/be/ Network_Resource_Name: http://pubs.usgs.gov/ds/618/data_files/fs/ Access_Instructions: Data can be downloaded via the World Wide Web (WWW) Offline_Option: Offline_Media: DVD Recording_Format: DVD Fees: Vary Ordering_Instructions: Contact U.S. Geological Survey. Turnaround: Vary Custom_Order_Process: Contact U.S. Geological Survey for details. Available_Time_Period: Time_Period_Information: Single_Date/Time: Calendar_Date: 20100306 Metadata_Reference_Information: Metadata_Date: 20201013 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Xan Fredericks Contact_Organization: Jacobs Technology, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: GIS Analyst/Metadata Specialist Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 (x3086) Contact_Electronic_Mail_Address: afredericks@usgs.gov Hours_of_Service: M-F, 8:00-4:00 EST Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time