Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 20170324 Title: Lidar-Derived Classified Point-Cloud for Coastal Topography—Assateague Island, Maryland and Virginia, Post-Hurricane Hermine, 10-12 September 2016 Edition: first Geospatial_Data_Presentation_Form: binary point cloud Series_Information: Series_Name: U.S. Geological Survey Data Release Issue_Identification: doi:10.5066/F7NP22NH Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/F7NP22NH Description: Abstract: Binary point-cloud data were produced for Assateague Island, Maryland and Virginia, post-Hurricane Hermine, from remotely sensed, geographically referenced elevation measurements collected by Quantum Spatial using a Riegl VQ-880-G (532-nm wavelength circular scan and 1064-nm wavelength linear scan) lidar sensor. Purpose: The purpose of this project was to produce a highly detailed and accurate digital elevation map for Assateague Island, Maryland and Virginia for use as a management tool and to make these data available to natural-resource managers and research scientists. To ensure that SPCMSC data management protocols were followed, this survey was assigned a USGS field activity number (FAN), 16CNT03. Additional survey and data details are available at http://cmgds.marine.usgs.gov/fan_info.php?fan=16CNT03. USGS Contract: G16PC00016 Task Order Number: G16D01063 Supplemental_Information: Processed data products are used by the U.S. Geological Survey (USGS) CMGP's National Assessment 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. Lidar_Information: Lidar_Collection_Information: Lidar_Specification: U.S. Geological Survey National Geospatial Program lidar Base Specification, Version 1.2 Lidar_Sensor: Riegl VQ-880-G Lidar_Maximum_Returns: Unlimited Lidar_Nominal_Pulse_Spacing: 0.7 Lidar_Nominal_Pulse_Density: 2 Lidar_Aggregate_Nominal_Pulse_Spacing: 0.7 Lidar_Aggregate_Nominal_Pulse_Density: 2 Lidar_Flight_Height: 500 Lidar_Flight_Speed: 120 Lidar_Scan_Angle: 40 Lidar_Scan_Frequency: 160 Lidar_Pulse_Rate: 245 Lidar_Pulse_Duration: 1.3 Lidar_Pulse_Width: 35 Lidar_Central_Wavelength: 532 Lidar_Multiple_Pulses_In_Air: 0 Lidar_Beam_Divergence: 0.7 Lidar_Swath_Width: 364 Lidar_Swath_Overlap: 50 Lidar_Geoid: National Geodetic Survey (NGS) Geoid12B Lidar_Accuracy_Information: Lidar_Calculated_Horizontal_Accuracy: 19.6 Lidar_Raw_Nonvegetated_Vertical_Accuracy: 0.072 Lidar_Raw_Nonvegetated_Vertical_Accuracy_Checkpoints: 13 Lidar_LAS_Information: Lidar_LAS_Version: 1.4 Lidar_LAS_Point_Record_Format: 6 Lidar_LAS_Witheld_Point_Identifier: Withheld (ignore) points were identified in these files using the standard LAS Withheld bit Lidar_LAS_Overage_Point_Identifier: Swath overage points were identified in these files using the standard LAS overlap bit Lidar_LAS_Radiometric_Resolution: 16 Lidar_LAS_Classification: Lidar_LAS_Class_Code: 1 Lidar_LAS_Class_Description: Processed, but Unclassified Lidar_LAS_Classification: Lidar_LAS_Class_Code: 2 Lidar_LAS_Class_Description: Bare earth ground Lidar_LAS_Classification: Lidar_LAS_Class_Code: 7 Lidar_LAS_Class_Description: Low Noise Lidar_LAS_Classification: Lidar_LAS_Class_Code: 17 Lidar_LAS_Class_Description: Bridge Decks Lidar_LAS_Classification: Lidar_LAS_Class_Code: 40 Lidar_LAS_Class_Description: Bathymetric Bottom Lidar_LAS_Classification: Lidar_LAS_Class_Code: 41 Lidar_LAS_Class_Description: Water Surface Lidar_LAS_Classification: Lidar_LAS_Class_Code: 45 Lidar_LAS_Class_Description: Water Column Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20160910 Ending_Date: 20160912 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:86f6d7f7-0ab5-4779-b611-d1d293d1b775 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Digital Elevation Model Theme_Keyword: DEM Theme_Keyword: extratropical cyclone Theme_Keyword: laser altimetry Theme_Keyword: lidar Theme_Keyword: Cessna Caravan Theme_Keyword: remote sensing Theme_Keyword: shoreline Theme_Keyword: submerged topography Theme_Keyword: topography Theme: Theme_Keyword_Thesaurus: Global Change Master Science Directory Theme_Keyword: LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION Theme_Keyword: OCEAN > COASTAL PROCESSES > BARRIER ISLANDS Theme_Keyword: OCEAN > COASTAL PROCESSES > BEACHES Theme_Keyword: OCEAN > COASTAL PROCESSES > SHORELINE DISPLACEMENT 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: Geographic Names Information System Place_Keyword: Assateague Island Place_Keyword: Maryland Place_Keyword: Virginia Place_Keyword: Delmarva Peninsula Place_Keyword: United States Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: Bare Earth Stratum_Keyword: Submerged Temporal: Temporal_Keyword_Thesaurus: None Temporal_Keyword: 2016 Temporal_Keyword: Post-Hurricane Hermine Access_Constraints: None Use_Constraints: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Xan Fredericks Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Cartographer/Lidar Coordinator 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: 727 502-8086 Contact_Facsimile_Telephone: 727 502-8182 Contact_Electronic_Mail_Address: afredericks@usgs.gov Hours_of_Service: M-F, 8:00-4:00 ET 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 periods may be inaccurate because of 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 7 Enterprise Service Pack 1; Esri ArcCatalog 10.2.2.3552 Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -75.42335013 East_Bounding_Coordinate: -75.07955612 North_Bounding_Coordinate: 38.33510704 South_Bounding_Coordinate: 37.83868211 Data_Quality_Information: Logical_Consistency_Report: Quantum Spatial reports that data cover the entire area specified for this project, approximately 52,196.2 acres. Positional_Accuracy: Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Quantum Spatial reports that the contract specifications required that raw Non-vegetated Vertical Accuracy (NVA) be computed from the both the raw lidar point cloud swath files and the derived DEMs. Additionally, Vegetated Vertical Accuracy (VVA) was also to be computed from the derived DEMS. The NVA was tested with 13 independent check points provided to QSI by USGS located in open terrain, and distributed throughout the project as feasible. These check points were not used in the calibration or post processing of the lidar point cloud data. The VVA was tested with 12 independent check points, also provided to QSI by USGS, located in vegetated terrain and also witheld from the calibration and post processing of the lidar point cloud data. VVA points were also distributed throughout the project area as feasible. Specifications for this project require that the NVA be 19.6 meters or better AccuracyZ at 95% confidence level and that the VVA be 29.4 cm or better AccuracyZ at the 95th percentile. NVA Root Mean Square Error (RMSE) was calculated using the 13 independent check points provided by the USGS and resulted in a value of 0.072m. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 0.072 meters AccuracyZ at the 95 percent Confidence Interval for Raw LAS NVA. 0.063 meters AccuracyZ at the 95 percent Confidence Interval for DEM NVA. 0.137 meters AccuracyZ at the 95th percentile for DEM VVA. Vertical_Positional_Accuracy_Explanation: 0.072 meters AccuracyZ at the 95 percent Confidence Interval for Raw LAS NVA. 0.063 meters AccuracyZ at the 95 percent Confidence Interval for DEM NVA. 0.137 meters AccuracyZ at the 95th percentile for DEM VVA. Quantum Spatial reports that the 13 independent NVA check points were surveyed using the closed level loop technique. Elevations interpolated from the unclassified lidar surface were compared to the elevation values of the surveyed NVA check points. The RMSE was computed to be 0.037 meters resulting in an AccuracyZ at the 95% confidence level of 0.072 meters. The 13 NVA check points were also compared to the elevations of the derived bare earth DEMs. The RMSE was computed to be 0.032 meters resulting in an AccuracyZ of 0.063 meters at the 95% confidence level. NVA AccuracyZ has been tested and meets the required 19.6 meter NVA at 95% confidence level using (RMSEz * 1.9600) for both the raw lidar point cloud and derived DEMs, as defined by the National Standards for Spatial Data Accuracy (NSSDA) and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. The 13 VVA check points were also surveyed using the closed level loop technique. Elevations for these points were compared to the elevations of the derived bare earth DEMs. The RMSE was computed to be 0.078 meters resulting in an AccuracyZ of 0.137 meters at the 95th percentile. AccuracyZ has been tested on the derived bare earth DEMs and meets the required 29.4 meter VVA using the 95th percentile of the absolute value of all vertical errors in all combined vegetation classes as defined by the National Standards for Spatial Data Accuracy (NSSDA); and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. Lineage: Process_Step: Process_Description: Quantum Spatial reports the following steps for Lidar Pre-Processing: 1. Review flight lines and data to ensure complete coverage of the study area and positional accuracy of the laser points. 2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. 3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey. 4. Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las format. Convert data to orthometric elevations by applying a geoid correction. 5. Import raw laser points into manageable blocks to perform manual relative accuracy calibration and filter erroneous points. Apply the refraction correction necessary for bathymetric data. Classify ground/bathymetric points for individual flight lines. 6. Using ground classified points per each flight line, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flight lines and apply results to all points in a flight line. Use every flight line for relative accuracy calibration. 7. Adjust the point cloud by comparing ground classified points to supplemental ground control points. Source_Used_Citation_Abbreviation: Base_Station_Control, SBETs, SGCPs, RAW_lidar Process_Date: 20161130 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Quantum Spatial Contact_Address: Address_Type: mailing and physical Address: 517 SW 2nd Street, Suite 400 City: Corvallis State_or_Province: OR Postal_Code: 97333 Country: USA Contact_Voice_Telephone: 541-752-1204 Contact_Facsimile_Telephone: 541-752-3770 Hours_of_Service: Monday through Friday 8:30 AM to 5:00 PM (Pacific Standard Time) Process_Step: Process_Description: Quantum Spatial reports the following steps for Lidar Post-Processing: 1. Classify data to ground and other client designated classifications using proprietary classification algorithms. 2. Manually QC data classification 3. After completion of classification and final QC approval, calculate density information and verify final accuracy calculations for the project using ground control quality check points. Source_Used_Citation_Abbreviation: Base_Station_Control, SBETs, QCPs, RAW_lidar Process_Date: 20161130 Source_Produced_Citation_Abbreviation: Classified_lidar Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Quantum Spatial Contact_Address: Address_Type: mailing and physical Address: 517 SW 2nd Street, Suite 400 City: Corvallis State_or_Province: OR Postal_Code: 97333 Country: USA Contact_Voice_Telephone: 541-752-1204 Contact_Facsimile_Telephone: 541-752-3770 Hours_of_Service: Monday through Friday 8:30 AM to 5:00 PM (Pacific Standard Time) 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 Completeness_Report: Quantum Spatial reports that these LAS files include all data points collected. No points have been removed or excluded. Shaded relief images have been visually inspected for data errors such as pits, border artifacts, and shifting. Lidar flight lines have been examined to ensure consistent elevation values across overlapping flight lines. The raw point cloud is of good quality and data passes Vertical Accuracy specifications. Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 18 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -75.000000 Latitude_of_Projection_Origin: 0 False_Easting: 500000.000000 False_Northing: 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 (2011) 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 (GEOID12B) Altitude_Resolution: 0.01 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Xan Fredericks Contact_Position: Cartographer/Lidar Coordinator, U.S. Geological Survey 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: 727 502-8086 Hours_of_Service: M-F, 8:00-4:00 ET Resource_Description: ASIS2016_HRHM_SM_z18_n88g12B_classified.laz Distribution_Liability: Although these data have been 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: Compressed LAS (LAZ) Format_Specification: Compressed LAS (LAZ) Format_Version_Number: 1.4 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-F7NP22NH/data/ASIS2016_HRHM_SM_z18_n88g12B_classified.zip Fees: None Custom_Order_Process: Contact U.S. Geological Survey for details. Metadata_Reference_Information: Metadata_Date: 20201102 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Xan Fredericks Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Cartographer/Lidar Coordinator 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: 727 502-8086 Contact_Electronic_Mail_Address: afredericks@usgs.gov Hours_of_Service: M-F, 8:00-4:00 ET Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time