Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2017 Title: EAARL Coastal Topography--Assateague Island National Seashore, Maryland and Virginia, 2005: Bare Earth Edition: second Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: U.S. Geological Survey Data Release Issue_Identification: doi:10.5066/F77H1GR0 Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/F77H1GR0 Description: Abstract: ASCII XYZ point cloud data were produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over Assateague Island National Seashore using the first-generation National Aeronautics and Space Administration (NASA) 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 60 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 NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 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. Purpose: The purpose of this project was to provide highly detailed and accurate elevation data of the Assateague Island National Seashore in 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 St. Petersburg Coastal and Marine Science Center (SPCMSC) data management protocols were followed, this survey was assigned a USGS field activity number (FAN), 05LTS12. Additional survey and data details are available at http://cmgds.marine.usgs.gov/fan_info.php?fan=05LTS12. 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 USGS'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 originally 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 "first returns" are indicative of vegetation-canopy height, or bare ground in the absence of vegetation, whereas "last returns" typically represent "bare-earth" elevations under vegetation. The terms first surface and bare earth refer to the digital elevation data of the terrain, but while first-surface data include vegetation, buildings, and other manmade structures, 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 (Geoid 12B). The development of custom software for creating these data products has been supported by the USGS CMGP's Lidar for Science and Resource Management project. Processed data products are used by the 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. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20050913 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:4424c537-4395-411a-a1c9-23071f42afd2 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Airborne Lidar Processing System Theme_Keyword: ALPS Theme_Keyword: EAARL Theme_Keyword: Experimental Advanced Airborne Research Lidar Theme_Keyword: laser altimetry Theme_Keyword: lidar Theme_Keyword: remote sensing Theme_Keyword: topography Theme_Keyword: USGS National Assessment Project Theme_Keyword: ASCII XYZ (Bare earth) 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: Maryland Place_Keyword: Virginia Place_Keyword: Assateague Island Place_Keyword: Atlantic Ocean Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: Bare earth Temporal: Temporal_Keyword_Thesaurus: None Temporal_Keyword: 2005 Access_Constraints: None Use_Constraints: 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: Christine Kranenburg Contact_Organization: Cherokee Nation Technologies, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Computer Scientist 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: 727 502-8129 Contact_Facsimile_Telephone: 727 502-8182 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Hours_of_Service: M-F, 8:00-4:00 ET Data_Set_Credit: Acknowledgment of the USGS 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 USGS 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 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.1.4959 Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -75.308193 East_Bounding_Coordinate: -75.091898 North_Bounding_Coordinate: 38.326038 South_Bounding_Coordinate: 37.947185 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 are as follows: attitude within 0.07 degree, 3-cm nominal ranging accuracy, and vertical elevation accuracy of +/-15 cm for the topographic surface. Quality checks are built into the data-processing software. Logical_Consistency_Report: These data were processed for topography ONLY. Completeness_Report: These point-cloud data may appear sparse or nonexistent, which is a result of automated filtering, manual removal of artifacts or lack of survey coverage. 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: Point elevation measurements have been determined to be within +/- 15 cm in vertical accuracy. Lineage: Process_Step: Process_Description: The data were collected using a Cessna 310 aircraft. The 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 USGS office in St. Petersburg, Florida. Raw EAARL waveform, GPS, and Inertial Measurement Unit (IMU) data were subsequently loaded into ALPS software. ALPS (20060918), interactively processed small sections of the data to obtain best estimates of aircraft pitch and roll biases. Process_Date: 20060918 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jeremy Bracone Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: GIS 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: 727-502-8129 Contact_Electronic_Mail_Address: eaarl-meta@usgs.gov Hours_of_Service: M-F, 8:00-4:00 ET Process_Step: Process_Description: ALPS (20060918-20061023) was used to batch process the raw data for first and last return topography. Next, it batch filtered the point cloud using the interactive RCF. The input parameters of the random consensus filter were: grid cell size (buffer) = 500 cm x 500 cm; vertical tolerance (vertical width) = 50 cm. The data were then manually edited to ensure anomalies and noise were addressed to specification. Process_Date: 20061023 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jeremy Bracone Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: GIS Specialist Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8129 Contact_Electronic_Mail_Address: eaarl-meta@usgs.gov Process_Step: Process_Description: The final .pbd (Portable Data Base) format files were loaded into ALPS (20161216) to remove any data from the tile buffers and merge them into a single product, which was then datum converted from ITRF00 to NAD83, NAVD88 using the Geoid12B model, and exported to an ASCII XYZ file. Tile buffers are an overlap region extending 200 meters past the edges of the 2-Km tile and contain duplicate data from adjacent tiles. The final .xyz file consists of four columns, UTM Easting, UTM Northing, elevation, and time. Process_Date: 20161216 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine Kranenburg Contact_Organization: Cherokee Nation Technologies, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Computer Scientist Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8129 Contact_Electronic_Mail_Address: ckranenburg@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: Direct_Spatial_Reference_Method: 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: 18N Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -75.000000 Latitude_of_Projection_Origin: 0.000000 False_Easting: 500000.000000 False_Northing: 0.000000 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: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Resolution: 0.01 m 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 attributes included in this data file are: NAD83 UTM Zone 18 easting values in meters, NAD83 UTM Zone 18 northing values in meters, NAVD88 elevations in meters and time as seconds of epoch (seconds). Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/of/2009/1078/ Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Christine Kranenburg Contact_Organization: Cherokee Nation Technologies, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Computer Scientist Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8129 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Resource_Description: ASIS2005_EAARLA_BE_z18_n88g12B.xyz 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: ASCII Format_Specification: XYZ Format_Version_Number: 1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-F77H1GR0/data/ASIS2005_EAARLA_BE_z18_n88g12B.zip Access_Instructions: Available Online Fees: None, if obtained online. Metadata_Reference_Information: Metadata_Date: 20201013 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Christine Kranenburg Contact_Organization: Cherokee Nation Technologies, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Contact_Position: Computer Scientist Contact_Address: Address_Type: Physical and Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: (727) 502-8129 Contact_Electronic_Mail_Address: ckranenburg@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time