Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2013 Title: Topographic Lidar Survey of Dauphin Island, Alabama and Chandeleur, Stake, Grand Gosier and Breton Islands, Louisiana, July 12-14, 2013 -- Bare Earth Digital Elevation Models (DEMs) Geospatial_Data_Presentation_Form: remote-sensing image Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: 838 Publication_Information: Publication_Place: St. Petersburg, Fla. Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/ds/838 Description: Abstract: A topographic lidar survey was conducted on July 12-14, 2013 over Dauphin Island, Alabama and Chandeleur, Stake, Grand Gosier and Breton Islands, Louisiana. The data were collected at a nominal pulse space of 1 meter (m) and processed to identify bare earth elevations. Bare earth Digital Elevation Models (DEMs) were generated based on these data. Photo Science, Inc., 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 projected to Universal Transverse Mercator (UTM), Zone 16, North American Datum (NAD) 1983, meters (m) coordinates. Their vertical datum is NAVD88 (GEOID12A) meters. Eighty-five 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 barrier island systems. Specifically, this survey supports detailed studies of Chandeleur and Dauphin Islands that resolve annual changes in beaches, berms and dunes associated with processes driven by storms, sea-level rise, and even human restoration activities. Supplemental_Information: Lidar data acquisition, calibration, and follow-on processing were completed by Photo Science, Inc. Photo Science was contracted by the U.S. Geological Survey to conduct the work. The geographic extent of each tile falls on even 2000 x and y UTM Zone 16N NAD83 meters. The 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 6 digits of the file name are based on the lower-left (LL) xy coordinate of the tile. For example, tile name 16RCU324308 uses 324 to represent an LL x-coordinate of 324,000, and uses 308 to represent an LL y-coordinate of 3,308,000 (ignoring the first digit). Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20130712 Ending_Date: 20130714 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -89.207247 East_Bounding_Coordinate: -88.030572 North_Bounding_Coordinate: 30.289239 South_Bounding_Coordinate: 29.465167 Lidar_Bounding_Coordinates: Left_Bounding_Coordinate: 287679 Right_Bounding_Coordinate: 400086 Top_Bounding_Coordinate: 3261520 Bottom_Bounding_Coordinate: 3351293 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_Keyword: Digital Elevation Model Theme: Theme_Keyword_Thesaurus: GCMD Instrument Theme_Keyword: LIDAR > LIGHT DETECTION AND RANGING Place: Place_Keyword_Thesaurus: None Place_Keyword: Alabama Place_Keyword: Louisiana Place_Keyword: Gulf of Mexico Place_Keyword: Barrier Islands Place_Keyword: Gulf of Mexico Barrier Islands Place_Keyword: Stake Island Place_Keyword: Grand Gosier Island Place_Keyword: Breton Island Place_Keyword: Chandeleur Islands Place_Keyword: Dauphin Island Place_Keyword: United States Stratum: Stratum_Keyword_Thesaurus: General Stratum_Keyword: Bare Earth Temporal: Temporal_Keyword_Thesaurus: General Temporal_Keyword: 2013 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 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: 727-803-8747 Contact_Facsimile_Telephone: 727-803-2031 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. 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. Native_Data_Set_Environment: Contractor: MicroStation Version 8; TerraScan Version 13; TerraModeler Version 13; GeoCue Version 2012.1.27.7; ESRI ArcGIS 10.1; Global Mapper 13; ALS Post Processor 2.75 Build #25; Windows 7 Operating System Data_Quality_Information: Logical_Consistency_Report: The lidar data were tested by Photo Science for both vertical and horizontal accuracy. The DEMs are seamless from one tile to the next and have no gaps or no-data areas. Completeness_Report: A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. Positional_Accuracy: Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Fundamental vertical accuracy (FVA) was computed for the raw lidar point cloud swath files. The vertical accuracy was tested with 10 independent survey located in open terrain. These check points were used in the calibration and post processing of the lidar point cloud data. Specifications for this project required that the FVA be 18.13 centimeters (cm) or better AccuracyZ at 95 percent confidence level. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 1.2 cm AccuracyZ at 95 percent Confidence Interval Vertical_Positional_Accuracy_Explanation: The data was tested using 10 independent survey check points located in open terrain. The 10 independent check points were surveyed by the USGS St. Petersburg Coastal and Marine Science Center, St. Petersburg, Fla., using global position system (GPS) techniques. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control. The RMSEz was computed to be 0.012m. AccuracyZ has been tested to meet 18.13 cm FVA at 95 Percent confidence level using RMSEz x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Photo Science, Inc. Publication_Date: 20130904 Title: Lidar Raw Data for Gulf of Mexico Barrier Islands Geospatial_Data_Presentation_Form: lidar data Publication_Information: Publication_Place: Photo Science, Inc. Publisher: Photo Science, Inc. Aerial LiDAR Department Type_of_Source_Media: digital hard drive Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20130712 Ending_Date: 20130714 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. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2013 Title: Ground Control Points Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20130714 Ending_Date: 20130723 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 Report. Process_Step: Process_Description: Lidar Pre-Processing: Airborne global positioning system (GPS) and inertial measurement units (IMU) data were merged to develop a Single Best Estimate (SBET) of the lidar system trajectory for each lift. Lidar ranging data were initially calibrated using previous best parameters for this instrument and aircraft. Relative calibration was evaluated using advanced plane-matching analysis and parameter corrections were derived. This was repeated iteratively until residual errors between overlapping swaths, across all project lifts, were reduced to acceptable levels. Data were then block adjusted to match surveyed calibration control. Raw data FVA was checked using independently surveyed checkpoints. Swath overage points were identified and tagged within each swath file. The raw lidar data and the ground control points are intermediary datasets and are not included in this Data Series Report. Source_Used_Citation_Abbreviation: Raw Lidar Data Source_Used_Citation_Abbreviation: Ground Control Points Process_Date: 2013 Source_Produced_Citation_Abbreviation: Calibrated Lidar Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Photo Science, Inc. Contact_Address: Address_Type: mailing and physical Address: 523 Wellington Way City: Lexington State_or_Province: KY Postal_Code: 40503 Country: USA Contact_Voice_Telephone: 859-277-8700 Contact_Facsimile_Telephone: 859-277-8901 Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please send an email. You should receive a response within 24 hours. Process_Step: Process_Description: Lidar Post-Processing: The calibrated and controlled lidar swaths were processed using automatic point classification routines in proprietary software. These routines operate against the entire collection—all swaths, all lifts—eliminating character differences between files. Data were then distributed as virtual tiles to experienced lidar analysts for localized automatic classification, manual editing, and peer-based quality control (QC) checks. Supervisory QC monitoring of work in progress and completed editing ensured consistency of classification character and adherence to project requirements across the entire project area. All classification tags are stored in the original swath files. Source_Used_Citation_Abbreviation: Calibrated Lidar Datasets Process_Date: 2013 Source_Produced_Citation_Abbreviation: Classified Lidar Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Photo Science, Inc. Contact_Address: Address_Type: mailing and physical Address: 523 Wellington Way City: Lexington State_or_Province: KY Postal_Code: 40503 Country: USA Contact_Voice_Telephone: 859-277-8700 Contact_Facsimile_Telephone: 859-277-8901 Contact_Electronic_Mail_Address: bishop@photoscience.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please send an email. You should receive a response within 24 hours. Process_Step: Process_Description: The bare earth surface is then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bareearth surface is finalized, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond and Double Line Drain hydro flattening breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 m was also used around each hydro flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to classes approved by USGS. The overlap data was classified to Class 17 (Overlap Default) and Class 18 (Overlap Ground). These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS. All data was manually reviewed and remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper was used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth datasets. Photo Science proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information. Source_Used_Citation_Abbreviation: Classified Lidar Datasets Process_Date: 2013 Source_Produced_Citation_Abbreviation: Validated LAS Datasets Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Photo Science, Inc. Contact_Address: Address_Type: mailing and physical Address: 523 Wellington Way City: Lexington State_or_Province: KY Postal_Code: 40503 Country: USA Contact_Voice_Telephone: 859-277-8700 Contact_Facsimile_Telephone: 859-277-8901 Contact_Electronic_Mail_Address: bishop@photoscience.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours. Process_Step: Process_Description: Hydro Classification Breakline Processing: Class 2 lidar was used to create a bare earth surface model. The surface model was then used to heads-up digitize 2D breaklines of inland streams and rivers with a 30-m nominal width and inland ponds and lakes of 8,000 square meters or greater surface area. The breaklines were collected for classification purposes only. The provided breaklines are 2D features and do not contain a valid elevation attribute. All ground (ASPRS Class 2) lidar data inside of the collected inland breaklines were then classified as water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 m was used around each breakline feature. These points were moved from ground (ASPRS Class 2) to ignored ground (ASPRS Class 10). The breakline files were then translated to ESRI Shapefile format using ESRI conversion tools. Source_Used_Citation_Abbreviation: Validated LAS Datasets Process_Date: 2013 Source_Produced_Citation_Abbreviation: Hydro Classification Breaklines Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Photo Science, Inc. Contact_Address: Address_Type: mailing and physical Address: 523 Wellington Way City: Lexington State_or_Province: KY Postal_Code: 40503 Country: USA Contact_Voice_Telephone: 859-277-8700 Contact_Facsimile_Telephone: 859-277-8901 Contact_Electronic_Mail_Address: bishop@photoscience.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please send an email. You should receive a response within 24 hours. Process_Step: Process_Description: Raster DEM Process: Class 2 lidar was used to create a 1.0 m Raster DEM. Using automated scripting routines within ArcMap, an ERDAS Imagine IMG file was created for each tile. Each surface was reviewed using Global Mapper to check for surface anomalies or incorrect elevations found within the surface. Source_Used_Citation_Abbreviation: Validated LAS Datasets Source_Used_Citation_Abbreviation: Hydro Classification Breaklines Process_Date: 2013 Source_Produced_Citation_Abbreviation: Hydro Enforced Raster DEMs Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Photo Science, Inc. Contact_Address: Address_Type: mailing and physical Address: 523 Wellington Way City: Lexington State_or_Province: KY Postal_Code: 40503 Country: USA Contact_Voice_Telephone: 859-277-8700 Contact_Facsimile_Telephone: 859-277-8901 Contact_Electronic_Mail_Address: bishop@photoscience.com Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please send an email. You should receive a response within 24 hours. Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Tile 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: 0.9996 Longitude_of_Central_Meridian: -87.000000 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.01 Ordinate_Resolution: 0.01 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 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 Altitude_Resolution: 0.01 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, 1-m by 1-m resolution, 32-bit floating point continuous rasters in ERDAS Imagine format derived from bare earth classified lidar data. The vertical units are in meters, NAVD88, GEOID12a. Entity_and_Attribute_Detail_Citation: USGS. 2013. Topographic Lidar Survey of Dauphin Island, Alabama and Chandeleur, Stake, Grand Gosier and Breton Islands, Louisiana, July 12-14, 2013. 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: 727-803-8747 Hours_of_Service: Monday-Friday, 9:00-5:00 Eastern Time Resource_Description: DS 838 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/838/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: 20131023 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS 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: 727-803-8747 Contact_Facsimile_Telephone: 727-803-2031 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