| 2018 USGS Lidar: Fairfax County, VA | spatialRepresentationInfo|
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| (MI_Metadata) fileIdentifier: gov.noaa.nmfs.inport:61290 language: LanguageCode: eng characterSet: (MD_CharacterSetCode) UTF8 hierarchyLevel: (MD_ScopeCode) dataset hierarchyLevelName: Elevation contact: (CI_ResponsibleParty) organisationName: OCM Partners contactInfo: (CI_Contact) phone: (CI_Telephone) voice: (missing) address: (CI_Address) role: (CI_RoleCode) resourceProvider contact: (CI_ResponsibleParty) organisationName: NOAA Office for Coastal Management contactInfo: (CI_Contact) phone: (CI_Telephone) voice: (843) 740-1202 address: (CI_Address) deliveryPoint: 2234 South Hobson Ave city: Charleston administrativeArea: SC postalCode: 29405-2413 country: (missing) electronicMailAddress: coastal.info@noaa.gov onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov protocol: WWW:LINK-1.0-http--link name: NOAA Office for Coastal Management Website description: NOAA Office for Coastal Management Home Page function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) pointOfContact dateStamp: DateTime: 2023-05-30T18:10:32 metadataStandardName: ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data metadataStandardVersion: ISO 19115-2:2009(E) return to top spatialRepresentationInfo: (MD_VectorSpatialRepresentation) topologyLevel: (MD_TopologyLevelCode) geometricObjects: (MD_GeometricObjects) geometricObjectType: (MD_GeometricObjectTypeCode) point geometricObjectCount: 46889000362 return to top referenceSystemInfo: (MD_ReferenceSystem) referenceSystemIdentifier: (RS_Identifier) authority: (CI_Citation) title: NAD83(2011) date: (CI_Date) date: 2008-11-12 dateType: (CI_DateTypeCode) publication citedResponsibleParty: (CI_ResponsibleParty) organisationName: European Petroleum Survey Group contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://apps.epsg.org/api/v1/CoordRefSystem/6318/export/?format=gml role: (missing) code: urn:ogc:def:crs:EPSG:6318 version: 6.18.3 return to top referenceSystemInfo: (MD_ReferenceSystem) referenceSystemIdentifier: (RS_Identifier) authority: (CI_Citation) title: North American Vertical Datum of 1988 (NAVD88) (GEOID18) meters alternateTitle: North American Vertical Datum of 1988 (NAVD88) (GEOID18) meters citedResponsibleParty: (CI_ResponsibleParty) organisationName: (withheld) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://apps.epsg.org/api/v1/VerticalCoordRefSystem/5703/?api_key=gml name: North American Vertical Datum of 1988 (NAVD88) (GEOID18) meters description: Link to Geographic Markup Language (GML) description of reference system. function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) resourceProvider citedResponsibleParty: (CI_ResponsibleParty) organisationName: European Petroleum Survey Group contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.epsg.org/ name: European Petroleum Survey Group Geodetic Parameter Registry description: Registry that accesses the EPSG Geodetic Parameter Dataset, which is a structured dataset of Coordinate Reference Systems and Coordinate Transformations. function: (CI_OnLineFunctionCode) search role: (CI_RoleCode) publisher VerticalCS: metaDataProperty: CommonMetaData: type: vertical informationSource: OGP revisionDate: 2006-11-28 isDeprecated: false identifier: urn:ogc:def:cs:EPSG::6499 name: Vertical CS. Axis: height (H). Orientation: up. UoM: meter. remarks: Used in vertical coordinate reference systems. axis: CoordinateSystemAxis: descriptionReference: urn:ogc:def:axis-name:EPSG::9904 identifier: urn:ogc:def:axis:EPSG::114 axisAbbrev: H axisDirection: up code: urn:ogc:def:crs:EPSG::5703 return to top identificationInfo: (MD_DataIdentification) citation: (CI_Citation) title: 2018 USGS Lidar: Fairfax County, VA alternateTitle: va2018_fairfax_m9164_metadata date: (CI_Date) date: 2019-10-15 dateType: (CI_DateTypeCode) publication identifier: (MD_Identifier) authority: (CI_Citation) title: NOAA/NMFS/EDM date: (inapplicable) code: Anchor: InPort Catalog ID 61290 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inport/item/61290 protocol: WWW:LINK-1.0-http--link name: Full Metadata Record description: View the complete metadata record on InPort for more information about this dataset. function: (CI_OnLineFunctionCode) information role: (inapplicable) citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9164/breaklines/ protocol: WWW:LINK-1.0-http--link name: Hydro breaklines description: Link to data set breaklines. function: (CI_OnLineFunctionCode) download role: (inapplicable) citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9164/supplemental/20191022_VA_Fairfax_County_Lidar_Report.pdf protocol: WWW:LINK-1.0-http--link name: Dataset report description: Link to data set report. function: (CI_OnLineFunctionCode) download role: (inapplicable) citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov/dataviewer/ protocol: WWW:LINK-1.0-http--link name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV) description: The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer. function: (CI_OnLineFunctionCode) download role: (inapplicable) presentationForm: (unknown) abstract: Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1,765 individual 1000 m x 1000 m tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: Fairfax county, Virginia, covering approximately 597 square miles. Dataset Description: Fairfax county, Virginia 2019 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3. The data was developed based on a horizontal projection/datum of NAD83 (2011), Conus Albers, meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1765 individual 1000 m x 1000 m tiles, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 1000 m x 1000 m schema. Ground Conditions: Lidar was collected in late 2018, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Dewberry established a total of 26 ground control points that were used to calibrate the lidar to known ground locations established throughout the Fairfax county, Virginia project area. An additional 74 independent accuracy checkpoints, 42 in Bare Earth and Urban landcovers (42 NVA points), 32 in Tall Grass and Brushland/Low Trees categories (32 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. The NOAA Office for Coastal Management (OCM) downloaded the laz files from this USGS site ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_VA_Fairfax_County_2018/ and processed the data to the Data Access Viewer (DAV) and to https. The total number of files downloaded and processed was 1765. The hydro breaklines were also downloaded and are available at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM. This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. purpose: To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 1 meter cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. credit: Dewberry The custom download may be cited as National Oceanic and Atmospheric Administration (NOAA) Digital Coast Data Access Viewer. Charleston, SC: NOAA Office for Coastal Management. Accessed Aug 01, 2023 at https://coast.noaa.gov/dataviewer. status: (MD_ProgressCode) completed pointOfContact: (CI_ResponsibleParty) organisationName: NOAA Office for Coastal Management contactInfo: (CI_Contact) phone: (CI_Telephone) voice: (843) 740-1202 address: (CI_Address) deliveryPoint: 2234 South Hobson Ave city: Charleston administrativeArea: SC postalCode: 29405-2413 country: (missing) electronicMailAddress: coastal.info@noaa.gov onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov protocol: WWW:LINK-1.0-http--link name: NOAA Office for Coastal Management Website description: NOAA Office for Coastal Management Home Page function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) pointOfContact pointOfContact: (CI_ResponsibleParty) organisationName: NOAA Office for Coastal Management contactInfo: (CI_Contact) phone: (CI_Telephone) voice: (843) 740-1202 address: (CI_Address) deliveryPoint: 2234 South Hobson Ave city: Charleston administrativeArea: SC postalCode: 29405-2413 country: (missing) electronicMailAddress: coastal.info@noaa.gov onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov protocol: WWW:LINK-1.0-http--link name: NOAA Office for Coastal Management Website description: NOAA Office for Coastal Management Home Page function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) custodian resourceMaintenance: (MD_MaintenanceInformation) maintenanceAndUpdateFrequency: (MD_MaintenanceFrequencyCode) notPlanned graphicOverview: (MD_BrowseGraphic) fileName: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9164/supplemental/va2018_fairfax_m9164.kmz fileDescription: This graphic displays the footprint for this lidar data set. fileType: KML descriptiveKeywords: (MD_Keywords) keyword: EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION type: (MD_KeywordTypeCode) theme thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Science Keywords date: (missing) edition: 12.3 descriptiveKeywords: (MD_Keywords) keyword: CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA keyword: CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > VIRGINIA keyword: VERTICAL LOCATION > LAND SURFACE type: (MD_KeywordTypeCode) place thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Location Keywords date: (missing) edition: 12.3 descriptiveKeywords: (MD_Keywords) keyword: LIDAR > Light Detection and Ranging type: (MD_KeywordTypeCode) instrument thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Instrument Keywords date: (missing) edition: 14.9 descriptiveKeywords: (MD_Keywords) keyword: Airplane > Airplane type: (MD_KeywordTypeCode) platform thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Platform Keywords date: (missing) edition: 14.9 descriptiveKeywords: (MD_Keywords) keyword: erosion type: (MD_KeywordTypeCode) theme descriptiveKeywords: (MD_Keywords) keyword: Continent > North America > United States Of America > Virginia > Fairfax County type: (MD_KeywordTypeCode) place descriptiveKeywords: (MD_Keywords) keyword: Lidar - partner (no harvest) type: (MD_KeywordTypeCode) project thesaurusName: (CI_Citation) title: InPort date: (inapplicable) resourceConstraints: (MD_LegalConstraints) useConstraints: (MD_RestrictionCode) otherRestrictions otherConstraints: Cite As: OCM Partners, [Date of Access]: 2018 USGS Lidar: Fairfax County, VA [Data Date Range], https://www.fisheries.noaa.gov/inport/item/61290. resourceConstraints: (MD_Constraints) useLimitation: NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose. resourceConstraints: (MD_LegalConstraints) accessConstraints: (MD_RestrictionCode) otherRestrictions useConstraints: (MD_RestrictionCode) otherRestrictions otherConstraints: Access Constraints: None | Use Constraints: Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. | Distribution Liability: Any conclusions drawn from the analysis of this information are not the responsibility of USGS, NOAA, the Office for Coastal Management or its partners. resourceConstraints: (MD_SecurityConstraints) classification: (MD_ClassificationCode) unclassified classificationSystem: (missing) handlingDescription: (missing) aggregationInfo: (MD_AggregateInformation) aggregateDataSetName: (CI_Citation) title: NOAA Data Management Plan (DMP) date: (unknown) identifier: (MD_Identifier) authority: (CI_Citation) title: NOAA/NMFS/EDM date: (inapplicable) code: 61290 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ocmp/dmp/pdf/61290.pdf protocol: WWW:LINK-1.0-http--link name: NOAA Data Management Plan (DMP) description: NOAA Data Management Plan for this record on InPort. function: (CI_OnLineFunctionCode) information role: (inapplicable) associationType: (DS_AssociationTypeCode) crossReference spatialRepresentationType: (MD_SpatialRepresentationTypeCode) vector language: eng; US topicCategory: (MD_TopicCategoryCode) elevation environmentDescription: Riegl processing software; GeoCue; MicroStation; Terrasolid Suite; Esri Arc 10.6; Windows 10 extent: (EX_Extent) geographicElement: (EX_GeographicBoundingBox) westBoundLongitude: -77.584074 eastBoundLongitude: -77.027787 southBoundLatitude: 38.589431 northBoundLatitude: 39.064288 temporalElement: (EX_TemporalExtent) extent: TimePeriod: description: | Currentness: Ground Condition beginPosition: 2018-12-06 endPosition: 2018-12-26 supplementalInformation: USGS Contract No. G16PC00020 CONTRACTOR: Dewberry SUBCONTRACTOR: Axis Geospatial, LLC Lidar data were acquired and calibrated by Axis Geospatial Services. All follow-on processing was completed by the prime contractor. The following are the USGS lidar fields in JSON: { "ldrinfo" : { "ldrspec" : "U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3", "ldrsens" : "VQ-1560i", "ldrmaxnr" : "7", "ldrnps" : "0.35", "ldrdens" : "8", "ldranps" : "0.35", "ldradens" : "8", "ldrfltht" : "1303", "ldrfltsp" : "160", "ldrscana" : "58.52", "ldrscanr" : "2000", "ldrpulsr" : "376", "ldrpulsd" : "3", "ldrpulsw" : "0.9", "ldrwavel" : "1064", "ldrmpia" : "1", "ldrbmdiv" : "0.25", "ldrswatw" : "1460", "ldrswato" : "30", "ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B" }, "ldraccur" : { "ldrchacc" : "0.717", "rawnva" : "0.177", "rawnvan" : "41", "clsnva" : "0.173", "clsnvan" : "42", "clsvva" : "0.124", "clsvvan" : "32" }, "lasinfo" : { "lasver" : "1.4", "lasprf" : "6", "laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld bit.", "lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.", "lasintr" : "16", "lasclass" : { "clascode" : "1", "clasitem" : "Processed, but Unclassified" }, "lasclass" : { "clascode" : "2", "clasitem" : "Bare Earth Ground" }, "lasclass" : { "clascode" : "7", "clasitem" : "Low Noise" }, "lasclass" : { "clascode" : "9", "clasitem" : "Water" }, "lasclass" : { "clascode" : "20", "clasitem" : "Ignored Ground" }, "lasclass" : { "clascode" : "17", "clasitem" : "Bridge Decks" }, "lasclass" : { "clascode" : "18", "clasitem" : "High Noise" } }} return to top distributionInfo: (MD_Distribution) distributionFormat: (MD_Format) name: Zip version: (missing) fileDecompressionTechnique: Zip distributionFormat: (MD_Format) name: LAZ version: (missing) distributor: (MD_Distributor) distributorContact: (CI_ResponsibleParty) organisationName: NOAA Office for Coastal Management contactInfo: (CI_Contact) phone: (CI_Telephone) voice: (843) 740-1202 address: (CI_Address) deliveryPoint: 2234 South Hobson Ave city: Charleston administrativeArea: SC postalCode: 29405-2413 country: (missing) electronicMailAddress: coastal.info@noaa.gov onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov protocol: WWW:LINK-1.0-http--link name: NOAA Office for Coastal Management Website description: NOAA Office for Coastal Management Home Page function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) distributor transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9164/details/9164 protocol: WWW:LINK-1.0-http--link name: Customized Download description: Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options. function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9164/index.html protocol: WWW:LINK-1.0-http--link name: Bulk Download description: Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. They will be in an orthometric datum. function: (CI_OnLineFunctionCode) download return to top dataQualityInfo: (DQ_DataQuality) scope: (DQ_Scope) level: (MD_ScopeCode) dataset report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Vertical Positional Accuracy evaluationMethodDescription: The project specifications require that only Non-Vegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The required accuracy (ACCz) is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the bare earth and urban land cover classes. The NVA was tested with 41 checkpoints located in bare earth and urban (non-vegetated) areas. Note: one checkpoint was removed from the swath NVA testing because a vehicle was parked at the xy location of the survey checkpoint. As non-ground points have not been separated from ground points at this stage, the point was excluded from swath NVA testing but was used during classified lidar and DEM testing. These check points were not used in the calibration or post processing of the lidar point cloud data. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. 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 points. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) 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. Tested 0.173 meters NVA at a 95% confidence level (8.8 cm RMSE) using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the raw lidar point cloud swath files was calculated against TINs derived from the final calibrated and controlled swath data using 41 independent checkpoints located in Bare Earth and Urban land cover classes. result: (missing) report: (DQ_CompletenessCommission) nameOfMeasure: Completeness Report evaluationMethodDescription: These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications. Due to flight restrictions near the White House and National Mall, Dewberry was unable to provide full tiles along some parts of the Potomac River, which are in close proximty to Washington, D.C. There are 13 tiles affected and these void areas comprise approximately 0.29 square miles. A shapefile identifying these void areas is delivered with this dataset. result: (missing) report: (DQ_ConceptualConsistency) nameOfMeasure: Conceptual Consistency evaluationMethodDescription: Data covers the entire area specified for this project. result: (missing) lineage: (LI_Lineage) statement: Data collected by Dewberry for the USGS. NOAA OCM downloaded laz files from the USGS rockyftp site and processed them to make available on the Data Access Viewer (DAV). processStep: (LI_ProcessStep) description: The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Prime Contractor, LLC proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas selected in the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps match for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSEz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 1.3, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening. Synthetic points generated by Riegl processing software are present in this dataset and were used to fill MTA zones. Please see the final project report for more details on the synthetic points. dateTime: DateTime: 2019-01-01T00:00:00 processStep: (LI_ProcessStep) description: LAS Point Classification: The point classification is performed as described below. The bare earth surface is then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth 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 0.35 meters was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). 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 approved classes by USGS. The overlap data was classified using standard LAS overlap bit. 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 through numerous conference calls and project study areas. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper us 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. Dewberry 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. dateTime: DateTime: 2019-10-09T00:00:00 processStep: (LI_ProcessStep) description: The NOAA Office for Coastal Management (OCM) downloaded the laz files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_VA_Fairfax_County_2018/ These files were processed to the Data Access Viewer (DAV) and https. The total number of files downloaded and processed was 1765. The data were in Albers Equal Area (NAD83 2011), meters, coordinates and NAVD88 (Geoid12B) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 17 - Bridge Decks, 18 - High Noise, 20 - Ignored Ground. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 7, 9, 17, 18, 20. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 2. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid12B model, to convert from Albers Equal Area (NAD83 2011) coordinates in meters to geographic coordinates, to assign the geokeys, to sort the data by gps time and zip the data to database and to http. dateTime: DateTime: 2020-07-28T00:00:00 processor: (CI_ResponsibleParty) organisationName: Office for Coastal Management role: (CI_RoleCode) processor source: (LI_Source) sourceCitation: (CI_Citation) title: USGS date: (missing) processStep: (LI_ProcessStep) description: The vertical values in this data set have been converted to reference North American Vertical Datum of 1988 (NAVD88) (GEOID18) meters, using the GEOID18 grids provided by the National Geodetic Survey. Any datum and projection transformations were then done with the Office for Coastal Management 'datum_shift' program. Compression to an LAZ file was done with the LAStools 'laszip' program and can be unzipped with the same free program (laszip.org) Processing notes: dateTime: DateTime: 2023-08-01T07:20:24 processor: (CI_ResponsibleParty) individualName: NOAA Office for Coastal Management contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: coastal.info@noaa.gov role: (CI_RoleCode) processor | |