| 2017 Lidar: Town of York, ME | spatialRepresentationInfo|
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| (MI_Metadata) fileIdentifier: gov.noaa.nmfs.inport:50722 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 contactInstructions: Telephone: 843-740-1202 Email: coastal.info@noaa.gov role: (CI_RoleCode) pointOfContact dateStamp: DateTime: 2023-09-28T00:00:00 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: return to top referenceSystemInfo: 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: 2017 Lidar: Town of York, ME alternateTitle: me2017_york_m6368_metadata date: (CI_Date) date: 2017 dateType: (CI_DateTypeCode) publication identifier: (MD_Identifier) authority: (CI_Citation) title: NOAA/NMFS/EDM date: (inapplicable) code: Anchor: InPort Catalog ID 50722 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inport/item/50722 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: 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 contactInstructions: Telephone: 843-740-1202 Email: coastal.info@noaa.gov role: (CI_RoleCode) originator 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: Citation URL description: Link to the Data Access Viewer (DAV) where elevation, imagery, and land cover data are available for custom download. function: (CI_OnLineFunctionCode) download role: (inapplicable) citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov/dataregistry protocol: WWW:LINK-1.0-http--link name: Citation URL description: Link to the Digital Coast Data where many types of coastal data are available for download. function: (CI_OnLineFunctionCode) download role: (inapplicable) citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://coast.noaa.gov/ protocol: WWW:LINK-1.0-http--link name: Citation URL description: Link to the NOAA Office for Coastal Management (OCM) homepage 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/geoid18/6368/breaklines/ protocol: WWW:LINK-1.0-http--link name: Citation URL description: Link to the data set breaklines. function: (CI_OnLineFunctionCode) download role: (inapplicable) presentationForm: (unknown) abstract: Extent: The project area covers 76 sq. miles of the Town of York, ME. Ground Conditions During Flight: The project was flown in May 2017 during leaf off conditions and when there was no snow on the ground. The project area required LiDAR to be collected on 8 points/sq. meter equivalent to 4 points/sq. meter single swath or better and processed to meet the bare earth vertical accuracy as described with LiDAR Base Specifications v1.2. Project deliverables include: raw point cloud by swath, classified point cloud, Bare-Earth Surface (Raster DEM) 0.5m resolution, breaklines used for hydro-flattening Raw point cloud data is delivered by individual swath. All other deliverables are delivered in a 1050m x 1050m tiling scheme. OCM noted that there are inconsistencies in the class definitions and gps times. It is left to the user to determine the usability of the data. Classes available are: 1 - Unclassified 2 - Ground 7 - Low noise 9 - Water 10 - Ignored Ground (Breakline proximity) 12 - Overlap In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data and breakines are also available. These data are are available for custom download at the link provided in the URL section of this metadata record. This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. purpose: Provide a high resolution Raster Digital Elevation Model with 0.5 meter grid spacing and hydro-flattened breaklines. The purpose for developing the data sets for this project are for improving elevation data over the Town of York providing the greater community, such as recreation and science, with high resolution data, establishing baseline high-resolution topography Hydro Flattened breaklines are used to provide consistent elevations to a bare earth surface model. This allows the user to create ESRI Raster DEM, Triangular Irregular Networks and bare earth Classified LiDAR LAS files. credit: Aeroptic, LLC, Primus Consultants, LLC , the Town of York, ME 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 Dec 21, 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 contactInstructions: Telephone: 843-740-1202 Email: coastal.info@noaa.gov 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 contactInstructions: Telephone: 843-740-1202 Email: coastal.info@noaa.gov 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/geoid18/6368/supplemental/me2017_york_m6368.kmz fileDescription: This graphic displays the footprint for this lidar data set. fileType: kmz descriptiveKeywords: (MD_Keywords) keyword: EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION keyword: EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION type: (MD_KeywordTypeCode) theme thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Science Keywords date: (missing) edition: 17.0 descriptiveKeywords: (MD_Keywords) keyword: North America>United States>Maine type: (MD_KeywordTypeCode) place thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) date: (missing) descriptiveKeywords: (MD_Keywords) keyword: Light Detection and Ranging keyword: bare earth keyword: bare ground type: (MD_KeywordTypeCode) theme descriptiveKeywords: (MD_Keywords) keyword: 2017 keyword: May type: (MD_KeywordTypeCode) temporal 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]: 2017 Lidar: Town of York, ME [Data Date Range], https://www.fisheries.noaa.gov/inport/item/50722. 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 that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. | Distribution Liability: The Town of York shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics, if available, are not legal documents and are not intended to be used as such. These data are not of survey quality and not intended to be used for survey purposes. The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data. The Town of York give no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data be directly acquired from an Town of York source and not indirectly through other sources, which may have changed the data in some way. Although these data have been processed successfully on computer systems at the Town of York, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. User should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions.In no event shall the creators, custodians, or distributors of these data be liable for any damages arising out of its use, or from the inability of the customer to use these data for their intended. Any conclusions drawn from the analysis of this information are not the responsibility of Aeroptic, LLC, Primus Consultants, LLC , the town of York, ME, the NOAA 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: 50722 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ocmp/dmp/pdf/50722.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 language: eng; US topicCategory: (MD_TopicCategoryCode) oceans extent: (EX_Extent) geographicElement: (EX_GeographicBoundingBox) westBoundLongitude: -70.772045 eastBoundLongitude: -70.565639 southBoundLatitude: 43.07034 northBoundLatitude: 43.268821 temporalElement: (EX_TemporalExtent) extent: TimePeriod: description: | Currentness: Ground Condition beginPosition: 2017-05-15 endPosition: 2017-05-16 supplementalInformation: Contractor: Aeroptic, LLC. All acquisition and calibration and Ground control was completed by the prime contractor. Post processing and generation of deliverables was provided by Primus Consultants, LLC. return to top contentInfo: (MD_FeatureCatalogueDescription) complianceCode: false language: LanguageCode: eng includedWithDataset: false featureCatalogueCitation: (CI_Citation) title: All deliverables meet specifications in contract. date: (unavailable) return to top distributionInfo: (MD_Distribution) 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 contactInstructions: Telephone: 843-740-1202 Email: coastal.info@noaa.gov role: (CI_RoleCode) distributor transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6368 protocol: WWW:LINK-1.0-http--link name: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6368 description: Link to custom download points, grids, or contours from the Data Access Viewer (DAV) function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/6368/index.html protocol: WWW:LINK-1.0-http--link name: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/6368/index.html description: Link to bulk download laz files in geographic coordinates and elevations in NAVD88 meters function: (CI_OnLineFunctionCode) download return to top dataQualityInfo: (DQ_DataQuality) scope: (DQ_Scope) level: (MD_ScopeCode) dataset report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Horizontal Positional Accuracy evaluationMethodDescription: No information provided. result: (missing) report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Vertical Positional Accuracy evaluationMethodDescription: 0.16 meters AccuracyZ at 95% Confidence Interval (8 cm RMSE) The independent checkpoints were surveyed using GPS. Elevations from the unclassified LiDAR data surface and the classified LiDAR surface were measured for the x,y and z location for each check point. Elevations interpolated from the LiDAR surface were then compared to the elevation value of the surveyed control points. the RMSE was computed to be TBD meters. Accuracyz has been tested to meet =19.6 cm NVA at 95% confidence level using (RMSEz * 1.96000) as defined by the National Standards for Spatial Data Accuracy (NSSDA). A Survey Report of the check points and Absolute Accuracy Report is available from the owner. result: (missing) report: (DQ_CompletenessCommission) nameOfMeasure: Completeness Report evaluationMethodDescription: A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The classified las data is of good quality and data passes the specifications for USGS QL1 data. result: (missing) lineage: (LI_Lineage) statement: (missing) processStep: (LI_ProcessStep) description: LIDAR Preprocessing: Leica Cloud Pro Point cloud Processor software was used in the post processing of the airborne GPS and inertial data that is critical to the positioning and orientation of the sensor during all flights. Leica Cloud Pro provides the smoothed best estimate of trajectory (SBET) that is necessary for Leica ALS post processor to develop the point cloud from the LiDAR missions. Calibration of the data is done using the Leica Cloud Pro software. The .las files are imported in, prepped, and spatially indexed. Ground control points/check points are imported and a QA/QC module is run. Relative calibration was evaluated using advanced plane-matching analysis and parameter corrections. Relative calibration was repeated iteratively until errors between overlapping swaths, across all project lifts, was reduced to ±16cm on planar surfaces within the area of interest. A flight line separation report is exported to a .jp2 file. Global Mapper is used to view the .jp2 file to determine if the data is within the client’s specifications. A control report was generated to assess the RMSE of check points and ensure compliance with QL1 specification. At this point this data is ready for analysis, classification, and filtering to generate a bare earth surface model in which the above ground features are removed from the data set. processStep: (LI_ProcessStep) description: LIDAR Postprocessing: Subsequent to pre-processing, data were then distributed as virtual tiles to experienced LiDAR analysts for localized automatic classification, manual editing, and peer-based 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. The point cloud was manipulated within TerraScan and TerraModeler software was used for the automated data classification, manual cleanup, and bare earth generation from this data. Classification of the point cloud to contract specifications: 1-Unclassified, 2-Bare-earth ground, 3-Low Vegetation, 4-Medium Vegetation,5-High Vegetation, 7- Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, and 11-Withheld, 17-Bridge decks, 18-High Noise. Project specific macros were used to classify the ground, the three types of vegetation and to remove the side overlap between parallel flight lines. Client defined vegetation height ranges are 0-0.5 m (low), 0.51 – 1.5m (medium) and 1.51m and above (high). All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. After completion of classification and final QC approval, the NVA and VVA for the project are calculated. Sample areas for each land cover type present in the project was extracted and forwarded to the client, along with the results of the accuracy tests. Class 2 LiDAR was used to create a bare earth surface model. The surface model was then used to heads-up digitize 3D breaklines of inland streams and rivers with a 30 meter nominal width and inland ponds and lakes of 8,000 sq. meters or greater surface area. All data was processed in UTM NAD83 Zone 12, Meters. All ground (ASPRS Class 2) LiDAR data inside of the collected inland breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 0.7 meter was also used around each hydro flattened breakline feature. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 10). processStep: (LI_ProcessStep) description: Quality control by Aeroptic LLC completed independent QA/QC of the calibrated files, classified files and derivative products. QC module and other software was used validate the data sets for compliance with LiDAR Base Specifications v1.2. Outputs in included Data Check and Calibration Check Reports. Absolute Accuracy Reports for pre-and post-classified LiDAR date were also generated. All reports are on file with the owner. processStep: (LI_ProcessStep) description: Breakline:The LiDAR surface model was used to heads-up digitize 3D breaklines of inland streams and rivers with a 30 meter nominal width and Inland Ponds and Lakes of 8,000 sq. meters or greater surface area. all data was processed in UTM NAD83 Zone 19, Meters. All ground (ASPRS Class 2) LiDAR data inside of the collected inland breaklines were then classified to water (ASPRS Class 9)using TerraScan macro functionality. A buffer of 0.7 meter was also used around each hydro flattened feature. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 10). The breaklines were used to perform the hydrologic flattening of water bodies, and gradient hydrologic flattening of double line streams. Lakes, reservoirs and ponds, at a nominal minimum size of two (2) acres or greater, were compiled as closed polygons. The closed water bodies were collected at a constant elevation. Rivers and streams, at a nominal minimum width of 30.5 meters (100 feet), were compiled in the direction of flow with both sides of the stream maintaining an equal gradient elevation. processStep: (LI_ProcessStep) description: The NOAA Office for Coastal Management (OCM) received the point and raster dem data from the Town of York, ME. The files contained lidar elevation and intensity measurements. OCM noted that certain classes (13, 17, 18) and the gps times for this data set are inconsistent. It is left to the the user to determine the usability of this data. Points that were classified as 13, 17, 18 are not included as points available to the user. The data were in UTM Zone 19 (NAD83) meters coordinates and NAVD88 (Geoid12a) elevations in meters. OCM did the following processing to the data for Digital Coast storage and provisioning purposes: 1. Converted from UTM Zone 19 (NAD83) meters coordinates to geographic coordinates 2. Converted from NAVD88 elevations to NAD83 (2011) ellipsoid elevations using Geoid12a grids 3. Copied the laz files to database and https dateTime: DateTime: 2017-12-11T00:00:00 processor: (CI_ResponsibleParty) organisationName: Office for Coastal Management role: (CI_RoleCode) processor processStep: (LI_ProcessStep) description: In April 2019, after the data had been available for download from the Data Access Viewer for approximately one year, the NOAA Office for Coastal Management (OCM) determined that the elevation values in this data set were 1 to 1.5 m lower than valid elevations. After receiving the control point data from the Town of York, it appears that the data were originally in WGS84 ellipsoid heights and GEOID12a was applied to convert to NAVD88. However, GEOID12a should be applied to NAD83 ellipsoid heights, not WGS84. To correct the problem, OCM converted the WGS84 ellipsoid heights to NAD83 ellipsoid heights. The translation between ellipsoids was done as a Helmert Transform between IGS08 and NAD83(2011) using parameters t0 = 1997.0 x(t0) = 0.99343 m; y(t0) = -1.90331m; z(t0) = -0.52655 m epsilon_x(t0) = 25.91467 mas; epsilon_y(t0) = 9.42645 mas; epsilon_z(t0) = 11.59935 mas s(t0) = 1.71504 · 10-9 (unitless) taken from the IGS08->NAD83(2011) entry in https://www.ngs.noaa.gov/CORS/coords.shtml. No temporal shift was applied. The documentation on the original ellipsoid was incomplete. Essentially we only had WGS84 in a filename for the control points. IGS08 was assumed to be an appropriate reference frame for GNSS derived coordinates. dateTime: DateTime: 2019-04-25T00:00:00 processor: (CI_ResponsibleParty) organisationName: Office for Coastal Management role: (CI_RoleCode) processor 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: 2023-12-21T18:28:00 processor: (CI_ResponsibleParty) individualName: NOAA Office for Coastal Management contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: coastal.info@noaa.gov role: (CI_RoleCode) processor | |