| 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (Connecticut) | spatialRepresentationInfo|
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| (MI_Metadata) fileIdentifier: gov.noaa.nmfs.inport:49658 language: LanguageCode: eng characterSet: (MD_CharacterSetCode) UTF8 hierarchyLevel: (MD_ScopeCode) dataset 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: 2022-08-09T17:11:37 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: 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (Connecticut) alternateTitle: ct2014_usgs_cmgp_sandy_m4968_metadata date: (CI_Date) date: 2016-01-09 dateType: (CI_DateTypeCode) publication identifier: (MD_Identifier) authority: (CI_Citation) title: NOAA/NMFS/EDM date: (inapplicable) code: Anchor: InPort Catalog ID 49658 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inport/item/49658 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://coast.noaa.gov/dataviewer protocol: WWW:LINK-1.0-http--link name: Citation URL description: Online Resource 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: Online Resource function: (CI_OnLineFunctionCode) download role: (inapplicable) presentationForm: (unknown) abstract: The LiDAR data were processed to a bare-earth digital terrain model (DTM). Detailed breaklines and bare-earth Digital Elevation Models (DEMs) were produced for the project area. Data was formatted according to tiles with each tile covering an area of 1500m by 1500m. A total of 1,974 tiles were produced for the project encompassing an area of approximately 1,526 sq. miles. This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. purpose: The primary purpose of this project was to develop a consistent and accurate surface elevation dataset derived from high-accuracy Light Detection and Ranging (LiDAR) technology for the USGS Connecticut SANDY LiDAR Project Area. 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) asNeeded graphicOverview: (MD_BrowseGraphic) fileName: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4968/supplemental/ct2014_usgs_cmgp_sandy_m4968.kmz fileDescription: This graphic shows the lidar coverage for the 2014 lidar acquisition for Connecticut. fileType: kmz descriptiveKeywords: (MD_Keywords) keyword: Bare earth type: (MD_KeywordTypeCode) theme 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]: 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (Connecticut) [Data Date Range], https://www.fisheries.noaa.gov/inport/item/49658. 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. These data depict the heights at the time of the survey and are only accurate for that time. None. However, users should be aware that temporal changes may have occurred since this dataset 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. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data. | Distribution Liability: Any conclusions drawn from the analysis of this information are not the responsibility of Dewberry, Leading Edge Geomatics (LEG), 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: 49658 citedResponsibleParty: (CI_ResponsibleParty) organisationName: (inapplicable) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ocmp/dmp/pdf/49658.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 extent: (EX_Extent) geographicElement: (EX_GeographicBoundingBox) westBoundLongitude: -72.593 eastBoundLongitude: -72.197 southBoundLatitude: 41.183 northBoundLatitude: 42.049 temporalElement: (EX_TemporalExtent) extent: TimePeriod: description: | Currentness: Ground Condition beginPosition: 2014-04-27 endPosition: 2014-05-29 supplementalInformation: A footprint of this data set may be viewed in Google Earth at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4968/supplemental/ct2014_usgs_cmgp_sandy_m4968.kmz A lidar report for this project may be viewed here: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4968/supplemental/ct2014_usgs_cmgp_sandy_m4968_lidarreport.pdf return to top contentInfo: (MD_FeatureCatalogueDescription) complianceCode: false language: LanguageCode: eng includedWithDataset: false featureCatalogueCitation: (CI_Citation) title: none 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 role: (CI_RoleCode) distributor transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4968 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. function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4968/index.html protocol: WWW:LINK-1.0-http--link name: Bulk Download description: Simple download of data files. 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: Project specifications required a horizontal accuracy of 1 m based on a RMSEr (0.578m) x 1.7308. Only checkpoints photo-identifiable in the intensity imagery can be used to test the horizontal accuracy of the LiDAR. Photo-identifiable checkpoints in intensity imagery typically include checkpoints located at the ends of paint stripes on concrete or asphalt surfaces or checkpoints located at 90 degree corners of different reflectivity, e.g. a sidewalk corner adjoining a grass surface. The x,y coordinates of checkpoints, as defined in the intensity imagery, are compared to surveyed xy coordinates for each photo-identifiable checkpoint. These differences are used to compute the tested horizontal accuracy of the LiDAR. As not all projects contain photo-identifiable checkpoints, the horizontal accuracy of the LiDAR cannot always be tested. The DEMs are derived from the source LiDAR and 3D breaklines created from the LiDAR. Horizontal accuracy is not performed on the DEMs or breaklines. LiDAR vendors perform calibrations on the LiDAR sensor and compare data to adjoining flight lines to ensure LiDAR meets the 1 meter horizontal accuracy standard at the 95% confidence level. Dewberry tested the horizontal accuracy of the LiDAR by comparing photo-identifiable survey checkpoints to the LiDAR Intensity Imagery. As only thirteen (13) checkpoints were photoidentifiable, the results are not statistically significant enough to report as a final tested value. However, the results are reported below. Using NSSDA methodology, horizontal accuracy at the 95% confidence level (called Accuracyr) is computed by the formula RMSEr x 1.7308. The dataset for the CT Sandy LiDAR project satisfies the criteria: Lidar dataset tested 0.660 m horizontal accuracy at 95% confidence level, based on RMSEr (0.381 m) x 1.7308. Please see the final project report delivered to the U.S. Geological Survey for more details. result: (missing) report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Vertical Positional Accuracy evaluationMethodDescription: The vertical accuracy of the bare earth DEMs tested by Dewberry with 104 independent survey checkpoints. The same checkpoints used to test the source LiDAR data were used to validate the vertical accuracy of final DEM products. The survey checkpoints are evenly distributed throughout the project area and located in areas of bare earth and open terrain (20), urban terrain (21), forest (21), brushland and trees (21), and high grass (21). Vertical accuracy is tested by extracting the elevation of the pixel that contains the x/y coordinates of the checkpoint and comparing these DEM elevations to the surveyed elevations. Checkpoints in open terrain were used to compute the Fundamental Vertical Accuracy (FVA). Project specifications required an FVA of 18.13 cm based on a RMSEz (9.25 cm) x 1.9600. All checkpoints were used to compute the Consolidated Vertical Accuracy (CVA). Project specifications require a CVA of 26.9 cm based on the 95th percentile. Supplemental Vertical Accuracy (SVA) will be computed on each individual land cover category other than open terrain. Target specifications for SVA are 26.9 cm based on the 95th percentile. Fundamental Vertical Accuracy (FVA) : 0.137 meters Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA methodology, vertical accuracy at the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.137 m vertical accuracy at 95% confidence level in open terrain, based on RMSEz (0.070 m) x 1.9600. Consolidated Vertical Accuracy (CVA): 0.201 meters Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, consolidated vertical accuracy (CVA) is computed using the 95th percentile method. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.201 m consolidated vertical accuracy at 95th percentile in all land cover categories combined. The 5% outliers consist of 6 checkpoints that are larger than the 95th percentile. These checkpoints have DZ values ranging between 0.203 m and 0.240 m. Supplemental Vertical Accuracy (SVA) Urban Land Cover: 0.098 meters Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, supplemental vertical accuracy (SVA) is computed using the 95th percentile method. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.098 m supplemental vertical accuracy at 95th percentile in the urban land cover category Forested and Fully Grown: 0.203 meters Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, supplemental vertical accuracy (SVA) is computed using the 95th percentile method. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.203 m supplemental vertical accuracy at 95th percentile in the forested and fully grown land cover category. Brush and Small Trees: 0.215 meters Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, supplemental vertical accuracy (SVA) is computed using the 95th percentile method. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.215 m supplemental vertical accuracy at 95th percentile in the brush and small trees land cover category. Tall Weeds and Crops: 0.192 meters Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, supplemental vertical accuracy (SVA) is computed using the 95th percentile method. The dataset for the Connecticut Sandy LiDAR project satisfies the criteria: DEM dataset tested 0.192 m supplemental vertical accuracy at 95th percentile in the tall weeds and crops land cover category. result: (missing) report: (DQ_CompletenessCommission) nameOfMeasure: Completeness Report evaluationMethodDescription: A visual qualitative assessment was performed to ensure data completeness and full tiles. No void or missing data exists. result: (missing) report: (DQ_ConceptualConsistency) nameOfMeasure: Conceptual Consistency evaluationMethodDescription: Data covers the pilot tile scheme provided for the project area. result: (missing) lineage: (LI_Lineage) statement: (missing) processStep: (LI_ProcessStep) description: Data for the USGS Connecticut Sandy LiDAR project was acquired by Leading Edge Geomatics (LEG) The project area included approximately 1,526 contiguous square miles for portions of Connecticut. LiDAR sensor data were collected with the Riegl 680i LiDAR system. The data was delivered in UTM Zone 18, horizontal datum NAD83(2011), vertical datum NAVD88, Geoid 12A. Deliverables for the project included a raw (unclassified) calibrated LiDAR point cloud, survey control, and a final acquisition/calibration report. A preliminary RMSEz error check is performed at this stage of the project life cycle in the raw LiDAR dataset against GPS static and kinematic data and compared to RMSEz project specifications. The LiDAR data is examined in open, flat areas away from breaks. Lidar ground points for each flightline generated by an automatic classification routine are used. Overall the LiDAR data products collected by LEG meet or exceed the requirements set out in the Statement of Work. The quality control requirements of LEGs quality management program were adhered to throughout the acquisition stage of this project to ensure product quality. LIDAR acquisition began on April 27, 2014 and was completed on May 29, 2014. A total of 40 survey missions were flown to complete the project. LEG utilized an Riegl 680i LiDAR system for the acquisition. The flight plan was flown as planned with no modifications. There were no unusual occurrences during the acquisition and the sensor performed within specifications. There were 428 flight lines required to complete the project. The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile any data if not complete. Subsequently the mission points are output using Trimble Business Center (TBC), initially with default values from Trimble or the last mission calibrated for system. The initial point generation for each mission calibration is verified within Microstation/Terrascan for calibration errors. If a calibration error greater than specification is observed within the mission, the roll pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are regenerated and validated internally once again to ensure quality. All missions are validated against the adjoining missions for relative vertical biases and collected GPS validation points for absolute vertical accuracy purposes. On a project level, a supplementary coverage check is carried out to ensure no data voids unreported by Field Operations are present. The initial points for each mission calibration are inspected for flight line errors, flight line overlap, slivers or gaps in the data, point data minimums, or issues with the LiDAR unit or GPS. Roll, pitch and scanner scale are optimized during the calibration process until the relative accuracy is met. Relative accuracy and internal quality are checked using at least 3 regularly spaced QC blocks in which points from all lines are loaded and inspected. Vertical differences between ground surfaces of each line are displayed. Color scale is adjusted so that errors greater than the specifications are flagged. Cross sections are visually inspected across each block to validate point to point, flightline to flightline and mission to mission agreement. For this project the specifications used are as follow: Relative accuracy <= 7cm RMSEZ within individual swaths and <=10 cm RMSEZ or within swath overlap (between adjacent swaths). UTM coordinate system, meters, zone 18, horizontal datum NAD83(2011), vertical datum NAVD88, Geoid 12A dateTime: DateTime: 2014-05-01T00:00:00 processStep: (LI_ProcessStep) description: Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All LiDAR related processes begin by importing the data into the GeoCue task management software. The swath data is tiled according to project specifications (1,500 m x 1,500 m). The tiled data is then opened in Terrascan where Dewberry uses proprietary ground classification routines to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. Once the ground routine has been completed a manual quality control routine is done using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review and supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification corrections were completed, the dataset was processed through a water classification routine that utilizes breaklines compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points that are within 1 meter of the hydrographic features are moved to class 10, an ignored ground due to breakline proximity. In addition to classes 1, 2, 9, and 10, there is a Class 7, noise points . This class was used for both low and high noise points. The fully classified dataset is then processed through Dewberry's comprehensive quality control program. The data was classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 7= Noise Class 9 = Water Class 10 = Ignored The LAS header information was verified to contain the following: Class (Integer) Adjusted GPS Time (0.0001 seconds) Easting (0.003 m) Northing (0.003 m) Elevation (0.003 m) Echo Number (Integer 1 to 4) Echo (Integer 1 to 4) Intensity (8 bit integer) Flight Line (Integer) Scan Angle (Integer degree) dateTime: DateTime: 2014-07-01T00:00:00 processStep: (LI_ProcessStep) description: Dewberry used GeoCue software to develop raster stereo models from the LiDAR intensity. The raster resolution was 0.3 m. dateTime: DateTime: 2014-08-01T00:00:00 processStep: (LI_ProcessStep) description: LiDAR intensity stereopairs were viewed in 3-D stereo using Socet Set for ArcGIS softcopy photogrammetric software. The breaklines are collected directly into an ArcGIS file geodatabase to ensure correct topology. The LiDARgrammetry was performed under the direct supervision of an ASPRS Certified Photogrammetrist. The breaklines were stereo-compiled in accordance with the Data Dictionary. Inland Lakes and Ponds, Streams and Rivers, Tidal Waters, and Bridge Breaklines were collected according to specifications for the Connecticut LiDAR Project. dateTime: DateTime: 2014-08-01T00:00:00 processStep: (LI_ProcessStep) description: Dewberry used ESRI software to generate bare earth elevation rasters. Bare earth elevation rasters do not contain bridges. As bridges are removed from bare earth DEMs but DEMs are continuous surfaces, the area between bridge abutments must be interpolated. The rasters are reviewed to identify locations where the interpolation between bridge abutments created bridge saddles. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: The locations of identified bridge saddles are loaded into Terrascan software. LiDAR points and surface models created from ground LiDAR points are reviewed and 3D bridge breaklines are compiled in Terrascan. Typically, two breaklines are compiled for each bridge-one breakline along the ground of each abutment. The bridge breaklines are placed perpendicular to the bridge deck and extend just beyond the extents of the bridge deck. Extending the bridge breaklines beyond the extent of the bridge deck allows the compiler to use ground elevations from the ground LiDAR data for each endpoint of the breakline. The 3D endpoints of each breakline are used to enforce a continuous slope on the ground under the bridge deck along the collected breakline. These breaklines are used in the final DEM production and help to reduce the appearance of bridge saddles. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: Breaklines are reviewed against LiDAR intensity imagery to verify completeness of capture. All breaklines are then compared to ESRI terrains created from ground only points prior to water classification. The horizontal placement of breaklines is compared to terrain features and the breakline elevations are compared to LiDAR elevations to ensure all breaklines match the LiDAR within acceptable tolerances. Some deviation is expected between breakline and LiDAR elevations due to monotonicity, connectivity, and flattening rules that are enforced on the breaklines. Once completeness, horizontal placement, and vertical variance is reviewed, all breaklines are reviewed for topological consistency and data integrity using a combination of ESRI Data Reviewer tools and proprietary tools. Corrections are performed within the QC workflow and re-validated. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: Class 2, ground, LiDAR points are exported from the LAS files into an Arc Geodatabase (GDB) in multipoint format. The 3D breaklines, Inland Lakes and Ponds, Streams and Rivers, Tidal Waters, and bridge breaklines are imported into the same GDB. An ESRI Terrain is generated from these inputs. The surface type of each input is as follows: Ground Multipoint: Masspoints Inland Lakes and Ponds: Hard Replace Streams and Rivers: Hard Line Tidal Waters: Hard Replace Bridge Breaklines: Hard Line dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: The ESRI Terrain is converted to rasters. The rasters are created to pre-defined extents so that multiple rasters are created over the project area. Creating multiple rasters rather than one large raster over a large project area makes the data more manageable to work with. The rasters are created with 2 tiles of overlap. This allows us to ensure seamless coverage and edge-matching in the final tiled product. These rasters were created with a 1 meter cell size. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: The DEMs that are created over large areas are reviewed in ArcGIS with hillshades. Hillshades allow the analyst to view the DEMs in 3D and to more efficiently locate and identify potential issues. The first review is done on the area DEMs as this increases the efficiency of any corrections that may be performed. Performing corrections on area DEMs allows the analyst to perform corrections on multiple tiles at once and helps prevent errors from occurring along individual tile seamlines. Analysts review the area DEMs for incorrect water elevations and artifacts that are introduced during the raster creation process. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: The corrected and final area DEMs are clipped to individual tiles. Dewberry uses a proprietary tool that clips the area DEMs to each tile located within the final Tile Grid, names the clipped DEM to the Tile Grid Cell name, and verifies that final extents are correct. All individual tiles are loaded into Global Mapper for the last review. During this last review, an analsyt checks to ensure full, complete coverage, no issues along tile boundaries, tiles seamlessly edge-match, and that there are no remaining processing artifacts in the dataset. dateTime: DateTime: 2015-01-01T00:00:00 processStep: (LI_ProcessStep) description: The NOAA Office for Coastal Management (OCM) received the topographic files in classified LAZ format from USGS' ftp site. The data were received in UTM Zone 18N NAD83 coordinates (meters) and vertically referenced to NAVD88 using the Geoid12a model in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. LAS files were compressed to LAZ format with LASTools. 2. LAS points which were duplicate or extraneous points (below -25 m) were removed. 3. The LAS files were transformed to geographic (decimal degrees), ellipsoidal coordinates (meters) referenced to the Geoid12a model. dateTime: DateTime: 2015-12-10T00:00:00 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: 2023-07-01T07:20:22 processor: (CI_ResponsibleParty) individualName: NOAA Office for Coastal Management contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: coastal.info@noaa.gov role: (CI_RoleCode) processor | |