Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 20131115 Title: Topographic Lidar Survey of the Chandeleur Islands, Louisiana, February 6, 2012 -- Bare Earth DEMs Geospatial_Data_Presentation_Form: remote-sensing image Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: 840 Publication_Information: Publication_Place: St. Petersburg, Fla. Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/ds/840 Description: Abstract: A topographic Lidar survey was conducted on February 6, 2012, over the Chandeleur Islands, Louisiana. The data were collected at a nominal pulse space of 0.5-meter (m) and processed to identify bare earth elevations. Bare earth digital elevation models (DEMs) were generated based on these data. Digital Aerial Solutions, LLC, was contracted by the U.S. Geological Survey (USGS) to collect and process the lidar data. The bare earth DEMs are 32-bit floating point ERDAS Imagine (IMG) files with a horizontal spatial resolution of 1-m by 1-m. They are in decimal degree geographic coordinates, North American Datum 1983, National Spatial Reference System 2007 (NAD83 NSRS2007)). Their vertical datum is North American Vertical Datum 1988, Geoid 2009, Geodetic Reference System 1980 (NAVD88 GEOID09 GRS80) in meters. Thirty-three DEMs, based on a 2-kilometer (km) by 2-km tiling scheme, cover the entire survey area. These lidar data are available to Federal, State and local governments, emergency-response officials, resource managers, and the general public. Purpose: This lidar survey was acquired to document the short- and long-term changes of several different barrier island systems. Specifically, this survey supports detailed studies of the Chandeleur Islands that resolve annual changes in beaches, berms and dunes associated with processes driven by storms, sea-level rise, and human restoration activities. Supplemental_Information: Lidar data acquisition, calibration, and follow-on processing were completed by Digital Aerial Solutions, LLC. Digital Aerial Solutions was contracted by the U.S. Geological Survey to conduct the work. Each tile is 2000 m by 2000 m in size, based on UTM Zone 16N NAD83 meters. The extent of each tile falls on even 1000 x and y UTM Zone 16N NAD83 coordinates. Tile names are assigned according to the U.S. National Grid (USNG) spatial address (http://www.fgdc.gov/usng/how-to-read-usng/index_html). The last 4 digits of the file name are based on the lower-left (LL) xy coordinate of the tile. For example, tile name 16RCU2304 uses 23 to represent an LL x-coordinate of 323,000 (ignoring the first digit), and uses 04 to represent an LL y-coordinate of 3,304,000 (ignoring the first two digits). Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20120206 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -88.9137598 East_Bounding_Coordinate: -88.8113368 North_Bounding_Coordinate: 30.0342555 South_Bounding_Coordinate: 29.7444381 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: model Theme_Keyword: remote sensing Theme_Keyword: elevation data Theme_Keyword: Lidar Theme_Keyword: Digital Elevation Model Theme_Keyword: DEM Theme_Keyword: topography Theme_Keyword: hydrology Theme_Keyword: laser altimetry Theme_Keyword: bare earth Theme: Theme_Keyword_Thesaurus: Global Change Master Science Directory (GCMD) Theme_Keyword: LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION Theme_Keyword: OCEAN > COASTAL PROCESSES > BARRIER ISLANDS Theme_Keyword: COASTAL PROCESSES > BEACHES Theme_Keyword: DOI/USGS/CMG > COASTAL AND MARINE GEOLOGY, U.S. GEOLOGICAL SURVEY, U.S. DEPARTMENT OF INTERIOR Theme: Theme_Keyword_Thesaurus: GCMD Instrument Theme_Keyword: Lidar > LIGHT DETECTION AND RANGING Place: Place_Keyword_Thesaurus: None Place_Keyword: Louisiana Place_Keyword: Gulf of Mexico Place_Keyword: Barrier Islands Place_Keyword: Gulf of Mexico Barrier Islands Place_Keyword: Chandeleur Islands Place_Keyword: United States Temporal: Temporal_Keyword_Thesaurus: General Temporal_Keyword: 2012 Access_Constraints: No restrictions apply to these data. Use_Constraints: None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nathaniel Plant Contact_Address: Address_Type: mailing and physical Address: 600 4th St. S. City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Facsimile_Telephone: 727-502-8001 Contact_Electronic_Mail_Address: nplant@usgs.gov Hours_of_Service: Monday through Friday 9:00 AM to 5:00 PM (Eastern Time) 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. The U.S. Geological Survey staff would also appreciate it if those products were shared with them. 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. Native_Data_Set_Environment: Microsoft Windows 7 Service Pack 2; ESRI ArcCatalog 9.3.1.1850; ArcMap 10; MicroStation V8; TeraScan v.11; TeraModel v.11. Data_Quality_Information: Logical_Consistency_Report: Bare-earth processed data for this acquisition block comply with the following accuracy requirements for Artifact/Feature removal: artifacts - 90 percent; outliers - 95 percent; vegetation - 95 percent; buildings - 98 percent. All LAS formatted Lidar data are validated using commercial GIS software to ensure proper formatting and loading before delivery. This validation procedure ensures that data on delivery media is in the correct physical format and is readable. Completeness_Report: The data was visually inspected for completeness. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Lidar data horizontal accuracy was tested to meet a 1.0 m root mean square error (RMSEz) or less. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 1m Horizontal_Positional_Accuracy_Explanation: Horizontal point accuracy is a function of angular origination of the pulse, IMU orientation, the scanner encoder and ranging function, and will vary depending on the proposed point density selected for the collection. Statistically, the error is roughly 1/3 of the illuminated footprint on the ground and is a function of beam divergences. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Lidar vertical data accuracy determination used the National Standard for Spatial Data Accuracy (NSSDA). The contract specified a 15 centimeter (cm) (RMSEz) or better on open bare terrain and a 43.6 cm (RMSEz) or better in vegetative areas. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 4.5cm Vertical_Positional_Accuracy_Explanation: Based on the vertical accuracy testing conducted by Digital Aerial Solutions, LLC using NSSDA methodology, the dataset tested 6.6 cm vertical accuracy at 95 percent confidence level in open terrain. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Digital Aerial Solutions, LLC. Publication_Date: 2012 Title: RAW Lidar Data Geospatial_Data_Presentation_Form: vector digital data Type_of_Source_Media: digital hard drive Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20120206 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Raw Lidar Data Source_Contribution: This data source was used to populate the Lidar point cloud data. This dataset is not included in this data series. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2012 Title: Ground Control Points Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20120206 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Ground Control Points Source_Contribution: This data source was used in Lidar processing and accuracy assessment. This dataset is not included in this data series. Process_Step: Process_Description: The airborne global positioning system (ABGPS), inertial measurement units (IMU), and raw ALS60 Lidar data were integrated into the Leica post processor software. The resultant file is in a LAS binary file format. The LAS file version 1.2 format can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the Lidar data (return number, intensity value, xyz, etc.). The resultant points are produced in the geodetic coordinates referenced to the vertical datum. The ABGPS, IMU and raw Lidar data are intermediary datasets and are not included in this data series. Source_Used_Citation_Abbreviation: Raw Lidar Data Process_Date: 2012 Source_Produced_Citation_Abbreviation: Calibrated Lidar Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Digital Aerial Solutions, LLC. Contact_Address: Address_Type: mailing and physical Address: 8409 Laurel Fair Circle Suite 100 City: Tampa State_or_Province: FL Postal_Code: 33610 Country: USA Contact_Voice_Telephone: 813-628-0788 Contact_Facsimile_Telephone: 813-628-0777 Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Process_Step: Process_Description: The unedited data were classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters was applied as appropriate for the production of bare earth Digital Terrain Models (DTMs). Interactive editing methods were applied to those areas where it was inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters were used to produce elevation height surfaces. The Lidar mass points are in American Society for Photogrammetry and Remote Sensing (ASPRS) LAS 1.2 format. The header file for each dataset is complete as defined by the LAS 1.2 specification. The data was classified as follows: Classes 1 and 17 = Unclassified. Class 2 = Ground. Class 9 = Water. Class 10 = Breakline Proximity. Source_Used_Citation_Abbreviation: Calibrated Lidar Datasets Process_Date: 2012 Source_Produced_Citation_Abbreviation: Classified Lidar Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Digital Aerial Solutions, LLC. Contact_Person: Joshua Helton Contact_Position: Director Lidar Programs Contact_Address: Address_Type: mailing and physical Address: 8409 Laurel Fair Circle Suite 100 City: Tampa State_or_Province: FL Postal_Code: 33610 Country: USA Contact_Voice_Telephone: 813-628-0788 Contact_Facsimile_Telephone: 813-628-0777 Contact_Electronic_Mail_Address: jhelton@digitalaerial.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Process_Step: Process_Description: The Spatial Reference Geographic (latitude and longitude) decimal degrees NAD83 coordinates were converted from ellipsoid heights (m) into orthometric heights using NAVD88 (m). The files were orthogonally tiled based on a 2000 m x 2000 m extent, and labeled with a "Tile_ID" attribute. Source_Used_Citation_Abbreviation: Classified Lidar Datasets Process_Date: 2012 Source_Produced_Citation_Abbreviation: Tiled Orthometric Lidar Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Digital Aerial Solutions, LLC. Contact_Person: Joshua Helton Contact_Position: Director Lidar Programs Contact_Address: Address_Type: mailing and physical Address: 8409 Laurel Fair Circle Suite 100 City: Tampa State_or_Province: FL Postal_Code: 33610 Country: USA Contact_Voice_Telephone: 813-628-0788 Contact_Facsimile_Telephone: 813-628-0777 Contact_Electronic_Mail_Address: jhelton@digitalaerial.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Process_Step: Process_Description: Breakline collection was done in order to create hydro-flattened Digital Elevation Models. Breaklines were collected for streams, rivers, and inland water bodies and visually inspected. Elevation from the Lidar point cloud is used to derive a static elevation for hydro flattening. Source_Used_Citation_Abbreviation: Classified Lidar datasets Process_Date: 2012 Source_Produced_Citation_Abbreviation: Hydro Breaklines Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Digital Aerial Solutions, LLC. Contact_Person: Joshua Helton Contact_Position: Director Lidar Programs Contact_Address: Address_Type: mailing and physical Address: 8409 Laurel Fair Circle Suite 100 City: Tampa State_or_Province: FL Postal_Code: 33610 Country: USA Contact_Voice_Telephone: 813-628-0788 Contact_Facsimile_Telephone: 813-628-0777 Contact_Electronic_Mail_Address: jhelton@digitalaerial.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Process_Step: Process_Description: The digital elevation models (DEMs) were derived from the classified lidar point cloud using ArcMap extension LP360. The DEMs are 32-bit floating point ERDAS Imagine IMG files with a cell size of less-than or equal to 1 m. All inland water bodies, streams, and rivers that were non-tidal water bodies were hydro-flattened within each DEM. The vertical accuracy of DEMs were assessed using methods adopted by the ASPRS National Digital Elevation Program (NDEP) for fundamental vertical accuracy (FVA) and consolidated vertical accuracy CVA. Source_Used_Citation_Abbreviation: Classified Lidar datasets Source_Used_Citation_Abbreviation: Hydro Breaklines Source_Used_Citation_Abbreviation: Ground Control Points Process_Date: 2012 Source_Produced_Citation_Abbreviation: Hydro Enforced Raster DEMs Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Digital Aerial Solutions, LLC Contact_Person: Joshua Helton Contact_Position: Director Lidar Programs Contact_Address: Address_Type: mailing and physical address Address: 8409 Laurel Fair Circle Suite 100 City: Tampa State_or_Province: FL Postal_Code: 33610 Country: USA Contact_Voice_Telephone: (813) 628-0788 Contact_Facsimile_Telephone: (813) 628-0777 Contact_Electronic_Mail_Address: jhelton@digitalaerial.com Hours_of_Service: 8:00 - 5:00 Eastern Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Tile Index Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 (NSRS2007) Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 (GEOID09) Altitude_Resolution: 0.00001 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The bare earth DEMs are composed of single band, 32-bit floating point continuous rasters in ERDAS Imagine format derived from bare earth classified lidar data. The vertical units are in meters, NAVD88, GEOID09. Entity_and_Attribute_Detail_Citation: USGS. 2013. Topographic Lidar Survey Chandeleur Islands, Louisiana, February 6, 2012. Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Nathaniel Plant Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, Fla. Contact_Position: Research Oceanographer 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: 727-502-8000 Hours_of_Service: Monday-Friday, 9:00-5:00 Eastern Time Resource_Description: DS 840 Distribution_Liability: Although these data were processed successfully on a computer system at the 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 and/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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ERDAS Imagine IMG, zipped Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/ds/840/data/ Fees: None if obtained online; otherwise prices vary. Ordering_Instructions: Publications are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone: 1-888-ASK-USGS, e-mail: infoservices@usgs.gov). Metadata_Reference_Information: Metadata_Date: 20131118 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: K. Guy 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_Facsimile_Telephone: 727-502-8001 Contact_Electronic_Mail_Address: kguy@usgs.gov Hours_of_Service: Monday through Friday 9:00 AM to 5:00 PM (Eastern Time) Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: None. Metadata_Use_Constraints: None. Metadata_Security_Information: Metadata_Security_Classification_System: None. Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: NONE