referenceSystemInfo
identificationInfo
distributionInfo
dataQualityInfo

2019 NOAA NGS Topobathy Lidar DEM: Chesapeake Bay, MD
 (MI_Metadata)
    fileIdentifier:  gov.noaa.nmfs.inport:65556
    language:
      LanguageCode:  eng
    characterSet:  (MD_CharacterSetCode) UTF8
    hierarchyLevel:  (MD_ScopeCode) dataset
    hierarchyLevelName:  Elevation
    contact:  (CI_ResponsibleParty)
        organisationName:  National Geodetic Survey
        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:  2021-10-28T12:52:22
    metadataStandardName:  ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data
    metadataStandardVersion:  ISO 19115-2:2009(E)
return to top
    referenceSystemInfo:  (MD_ReferenceSystem)
        referenceSystemIdentifier:  (RS_Identifier)
            code:  EPSG::6347
return to top
    identificationInfo:  (MD_DataIdentification)
        citation:  (CI_Citation)
            title:  2019 NOAA NGS Topobathy Lidar DEM: Chesapeake Bay, MD
            date:  (CI_Date)
                date:  2021
                dateType:  (CI_DateTypeCode) publication
            identifier:  (MD_Identifier)
                authority:  (CI_Citation)
                    title:  NOAA/NMFS/EDM
                    date: (inapplicable)
                code:
                  Anchor:  InPort Catalog ID 65556
            citedResponsibleParty:  (CI_ResponsibleParty)
                organisationName: (inapplicable)
                contactInfo:  (CI_Contact)
                    onlineResource:  (CI_OnlineResource)
                        linkage: https://www.fisheries.noaa.gov/inport/item/65556
                        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:  National Geodetic Survey
                contactInfo:  (CI_Contact)
                    phone:  (CI_Telephone)
                        voice: (missing)
                    address:  (CI_Address)
                        deliveryPoint:  1315 East-West Hwy
                        city:  Silver Spring
                        administrativeArea:  MD
                        postalCode:  20910
                        country: (missing)
                        electronicMailAddress: (missing)
                    onlineResource:  (CI_OnlineResource)
                        linkage: https://geodesy.noaa.gov/
                        protocol:  WWW:LINK-1.0-http--link
                        name:  National Geodetic Survey Website
                        description:  Website listed for National Geodetic Survey
                        function:  (CI_OnLineFunctionCode) information
                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:  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)
            citedResponsibleParty:  (CI_ResponsibleParty)
                organisationName: (inapplicable)
                contactInfo:  (CI_Contact)
                    onlineResource:  (CI_OnlineResource)
                        linkage: https://chs.coast.noaa.gov/htdata/lidar4_z/geoid18/data/9424/supplemental/NOAA_CB_1902_1903_Topobathymetric_Lidar_Report.pdf
                        protocol:  WWW:LINK-1.0-http--link
                        name:   Topobathymetric Lidar Data Report
                        description:  Topobathymetric Lidar Data Report
                        function:  (CI_OnLineFunctionCode) download
                role: (inapplicable)
            presentationForm: (unknown)
        abstract:  NOAA Chesapeake Bay MD1902 and MD1903 Topobathymetric lidar data were collected by NV5 Geospatial (NV5) using a Leica Chiroptera 4x system. The MD1903 acquisition spanned from 20191109-20191115 in 5 missions. The MD1902 acquisition spanned from 20191109-20191116 in 6 missions. The datasets include topobathymetric data in LAS format 1.4, point data record format 6, with the following classifications in accordance with project specifications and the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards: 1 - unclassified 2 - ground 7 - noise 40 - bathymetric bottom or submerged topography 41 - water surface 43 - submerged feature 45 - water column 46 - overlap bathy bottom - temporally different from a separate lift 71 - unclassified associated with areas of overlap bathy bottom/temporal bathymetric differences 72 - ground associated with areas of overlap bathy bottom/temporal bathymetric differences 81 - water surface associated with areas of overlap bathy bottom/temporal bathymetric differences 85 - water column associated with areas of overlap bathy bottom/temporal bathymetric differences 1 Overlap - edge clip 1 Withheld- green sensor returns within topographic areas 42 Synthetic - synthetic water surface These data sets also includes lidar intensity values, number of returns, return number, time, and scan angle. The 100 meter buffered NOAA Chesapeake Bay MD1902 project area covers approximately 260.195 square kilometers in an area encompassing Severn River to Rhode River near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The final classified lidar data were then transformed from ellipsoid to geoidal height (Geoid12b) and used to create 23 - 5,000 m x 5,000 m topobathymetric DEMs in GeoTIFF format with 1m pixel resolution. The 100 meter buffered NOAA Chesapeake Bay MD1903 project area covers approximately 273.518 square kilometers in an area encompassing West River to Dares Beach near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The final classified lidar data were then transformed from ellipsoid to geoidal height (Geoid12b) and used to create 18 - 5,000m x 5,000 m topobathymetric DEMs in GeoTIFF format with 1m pixel resolution.
        purpose:  This lidar data was required by National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS), Remote Sensing Division Coastal Mapping Program (CMP) to enable accurate and consistent measurement of the national shoreline. The CMP works to provide a regularly updated and consistent national shoreline to define America's marine territorial limits and manage coastal resources.
        credit:  National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey (NGS), Remote Sensing Division (RSD), Coastal Mapping Program (CMP)
        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) custodian
        resourceMaintenance:  (MD_MaintenanceInformation)
            maintenanceAndUpdateFrequency:  (MD_MaintenanceFrequencyCode) notPlanned
        graphicOverview:  (MD_BrowseGraphic)
            fileName: https://chs.coast.noaa.gov/htdata/lidar4_z/geoid18/data/9424/supplemental/extent_ngs_2019topobathy_chesBay_md_m9424.kmz
            fileDescription:  This graphic displays the footprint for this data set.
            fileType:  KML
        descriptiveKeywords:  (MD_Keywords)
            keyword:  EARTH SCIENCE > LAND SURFACE
            keyword:  EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY
            keyword:  EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
            keyword:  EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DIGITAL ELEVATION/TERRAIN MODEL (DEM)
            keyword:  EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY
            keyword:  EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY > COASTAL BATHYMETRY
            keyword:  EARTH SCIENCE > OCEANS > COASTAL PROCESSES > BEACHES
            keyword:  EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
            keyword:  EARTH SCIENCE > SPECTRAL/ENGINEERING > LIDAR
            type:  (MD_KeywordTypeCode) theme
            thesaurusName:  (CI_Citation)
                title:  Global Master Change Directory (GCMD) Science Keywords
                date: (missing)
        descriptiveKeywords:  (MD_Keywords)
            keyword:  CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MARYLAND
            type:  (MD_KeywordTypeCode) place
            thesaurusName:  (CI_Citation)
                title:  Global Master Change Directory (GCMD) Location Keywords
                date: (missing)
        descriptiveKeywords:  (MD_Keywords)
            keyword:  Aircraft > AIRCRAFT
            type:  (MD_KeywordTypeCode) platform
            thesaurusName:  (CI_Citation)
                title:  Global Master Change Directory (GCMD) Platform Keywords
                date: (missing)
        descriptiveKeywords:  (MD_Keywords)
            keyword:  DOC/NOAA/NOS/NGS > National Geodetic Survey, National Ocean Service, NOAA, U.S. Department of Commerce
            type:  (MD_KeywordTypeCode) dataCentre
            thesaurusName:  (CI_Citation)
                title:  Global Change Master Directory (GCMD) Data Center Keywords
                date:  (CI_Date)
                    date:  2017-04-24
                    dateType:  (CI_DateTypeCode) publication
                edition:  8.5
                citedResponsibleParty:  GCMD Landing Page
        descriptiveKeywords:  (MD_Keywords)
            keyword:  NGS Lidar
            type:  (MD_KeywordTypeCode) project
            thesaurusName:  (CI_Citation)
                title:  InPort
                date: (inapplicable)
        resourceConstraints:  (MD_LegalConstraints)
            useConstraints:  (MD_RestrictionCode) otherRestrictions
            otherConstraints:  Cite As: National Geodetic Survey, [Date of Access]: 2019 NOAA NGS Topobathy Lidar DEM: Chesapeake Bay, MD [Data Date Range], https://www.fisheries.noaa.gov/inport/item/65556.
        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 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:  65556
                citedResponsibleParty:  (CI_ResponsibleParty)
                    organisationName: (inapplicable)
                    contactInfo:  (CI_Contact)
                        onlineResource:  (CI_OnlineResource)
                            linkage: https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ngs/dmp/pdf/65556.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:  OS Independent
        extent:  (EX_Extent)
            geographicElement:  (EX_GeographicBoundingBox)
                westBoundLongitude:  -76.63455
                eastBoundLongitude:  -76.42723
                southBoundLatitude:  38.85567
                northBoundLatitude:  39.09947
            geographicElement:  (EX_GeographicDescription)
                geographicIdentifier:  (MD_Identifier)
                    code:  AOI for MD1902
            temporalElement:  (EX_TemporalExtent)
                extent:
                  TimePeriod:
                    description:   | Currentness: Ground Condition
                    beginPosition:  2019-11-09
                    endPosition:  2019-11-16
        extent:  (EX_Extent)
            geographicElement:  (EX_GeographicBoundingBox)
                westBoundLongitude:  -76.596687
                eastBoundLongitude:  -76.445444
                southBoundLatitude:  38.522624
                northBoundLatitude:  38.880334
            geographicElement:  (EX_GeographicDescription)
                geographicIdentifier:  (MD_Identifier)
                    code:  AOI for MD1903
            temporalElement:  (EX_TemporalExtent)
                extent:
                  TimePeriod:
                    description:   | Currentness: Ground Condition
                    beginPosition:  2019-11-09
                    endPosition:  2019-11-15
        supplementalInformation:  Data from MD1902 and MD1903 includes all lidar returns. An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. Depth values were adjusted per sensor to NOAA provided ground truth data. Bathymetric intensity values were normalized for water depth. Classes 2 (ground), 40 (submerged topography), and 43 (submerged object) were used to create the final DEMs. The full workflow used for this project will be documented in the NOAA Chesapeake Bay MD_1902_1903 Topobathymetric lidar final report.
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=9425
                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://chs.coast.noaa.gov/htdata/raster5/elevation/NGS_ChesepeakeBay_MD_topobathy_DEM_2019_9425
                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:  Horizontal Positional Accuracy
            evaluationMethodDescription:  Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95 percent of the time (ACCr). Based on a flying altitude of 400 meters, an IMU error of 0.005 decimal degrees, and a GNSS positional error of 0.015 meters, the RMSEr value for the MD1902 and MD1903 project area is 0.064 meters, with a ACCr of 0.11 meters at the 95% confidence level. The project specification requires horizontal positions to be accurate to 1.0m(RMSE).
            result: (missing)
        report:  (DQ_AbsoluteExternalPositionalAccuracy)
            nameOfMeasure:  Vertical Positional Accuracy
            evaluationMethodDescription:  Absolute accuracy was assessed using both Non-Vegetated Vertical Accuracy (NVA) and Vegetated Vertical Accuracy (VVA) survey methods. Survey checkpoints were evenly distributed as feasible throughout the project area. NVA compares known ground check point data that were withheld from the calibration and post-processing of the lidar point cloud to the derived gridded bare earth DEM. NVA is a measure of the accuracy of lidar point data in open areas with level slope (less than 20°) where the lidar system has a high probability of measuring the ground surface and is evaluated at the 95% confidence interval (1.96*RMSE). Vertical Positional Accuracy for MD1902 In the MD1902 data extent, 9 survey checkpoints were used to assess the vegetated vertical accuracy. Project specifications require VVA meet 0.36 m based on the 95th percentile tested against the derived bare earth DEM. Submerged topography points were tested separately. In the MD1902 data extent, 89 survey checkpoints were used to assess the submerged topography accuracy. Project specifications require submerged topography shall meet a vertical RMSE of QL2b specified in the Draft National Coastal Mapping strategy 1.0 which is equivalent to 0.30 m RMSE at a depth of 1 m. Please refer to the final data report for final accuracies. The MD1902 dataset Non-Vegetated Vertical Accuracy tested 0.064 m vertical accuracy at 95% confidence level against the derived bare earth DEM in open terrain using 25 ground check points, based on RMSEz (0.036 m) x 1.9600. The MD1902 dataset Vegetated Vertical Accuracy tested 0.119 m vertical accuracy at the 95th percentile against the derived bare earth DEM using 9 landclass points. The MD1902 dataset tested 0.136 m vertical accuracy at 95% confidence level against the derived topobathymetric bare earth DEM using 89 submerged check points, based on RMSEz (0.069 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m. Vertical Positional Accuracy for MD1903 In the MD1903 data extent, 11 survey checkpoints were used to assess the vegetated vertical accuracy. Project specifications require VVA meet 0.36 m based on the 95th percentile tested against the derived bare earth DEM. Submerged topography points were tested separately. In the MD1903 data extent, 43 survey checkpoints were used to assess the submerged topography accuracy. Project specifications require submerged topography shall meet a vertical RMSE of QL2b specified in the Draft National Coastal Mapping strategy 1.0 which is equivalent to 0.30 m RMSE at a depth of 1 m. Please refer to the final data report for final accuracies. The MD1903 dataset Non-Vegetated Vertical Accuracy tested 0.081 m vertical accuracy at 95% confidence level against the derived bare earth DEM in open terrain using 23 ground check points, based on RMSEz (0.041 m) x 1.9600. The MD1903 dataset Vegetated Vertical Accuracy tested 0.159 m vertical accuracy at the 95th percentile against the derived bare earth DEM using 11 landclass points. The MD1903 dataset tested 0.158 m vertical accuracy at 95% confidence level against the derived topobathymetric bare earth DEM using 43 submerged check points, based on RMSEz (0.081 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m.
            result: (missing)
        report:  (DQ_CompletenessCommission)
            nameOfMeasure:  Completeness Report
            evaluationMethodDescription:  Data covers the project boundary.
            result: (missing)
        report:  (DQ_ConceptualConsistency)
            nameOfMeasure:  Conceptual Consistency
            evaluationMethodDescription:  Not applicable
            result: (missing)
        lineage:  (LI_Lineage)
            statement: (missing)
            processStep:  (LI_ProcessStep)
                description:  Data for The NOAA Chesapeake Bay MD1903 Topobathymetric lidar project area was acquired by NV5 Geospatial (NV5) using a Leica Chiroptera 4x Topobathy lidar system. All derived LAS data is referenced to: Horizontal Datum-NAD83(2011) epoch: 2010.00 Projection-UTM Zone 18N Horizontal Units-meters Vertical Datum-NAVD88 (Geoid12b) Vertical Units-meters The collected lidar data were immediately processed in the field by NV5 to a level that will allow QA\QC measures to determine if the sensor is functioning properly and assess the coverage of submerged topography. An initial SBET was created in POSPAC MMS 8.3 SP3 and loaded into RiProcess which applies pre-calibrated angular misalignment corrections of scanner position to extract the raw point cloud into geo-referenced LAS files. These files were inspected for sensor malfunctions and then passed through automated raster generation using LAStools to develop an initial assessment of bathymetric coverage. NV5 reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points. These rasters were also used to create an initial product in Quick Look Coverage Maps. These Quick Look files are not fully processed data or final products but provide rapid assessment of approximate coverage and depth penetration.
                dateTime:
                  DateTime:  2021-07-08T00:00:00
                processor:  (CI_ResponsibleParty)
                    organisationName:  NGS Communications and Outreach Branch
                    contactInfo:  (CI_Contact)
                        phone:  (CI_Telephone)
                            voice:  (301) 713-3242
                        address:  (CI_Address)
                            electronicMailAddress:  ngs.infocenter@noaa.gov
                    role:  (CI_RoleCode) processor
            processStep:  (LI_ProcessStep)
                description:  NV5 resolved kinematic corrections for aircraft position data using aircraft GNSS and Applanix's proprietary PP-RTX solution. When PP-RTX was not used NV5 conducted static Global Navigation Satellite System (GNSS) ground surveys (1 Hz recording frequency) using base stations over known monument locations during flights. After the airborne survey, static GPS data were triangulated with nearby Continuously Operating Reference Stations (CORS) using the Online Positioning User Service (OPUS) for precise positioning. Multiple independent sessions over the same base station were performed to confirm antenna height measurements and to refine position accuracy. This data was used to correct the continuous on board measurements of the aircraft position recorded throughout the flight. A final smoothed best estimate trajectory (SBET) was developed that blends post-processed aircraft position with attitude data. Using the SBETs, sensor head position and attitude were then calculated throughout the survey. Trimble Business Center v.3.90, Blue Marble Geographic Calculator 2019, and PosPac MMS 8.3 SP3 were used for these processes. Following final SBET creation, NV5 used Leica Lidar Survey Studio (LSS) to calculate laser point positioning by associating SBET positions to each laser point return time, scan angle, and intensity. Leica LSS was used to derive a synthetic water surface to create a water surface model. Light travels at different speeds in air versus water and its direction of travel or angle is changed or refracted when entering the water column. The refraction tool corrects for this difference by adjusting the depth (distance traveled) and horizontal positioning (change of angle/direction) of the lidar data. All lidar data below water surface models were classified as water column to correct for refraction. Using raster-based QC methods, the output data is verified to ensure the refraction tool functioned properly.
                dateTime:
                  DateTime:  2021-07-08T00:00:00
            processStep:  (LI_ProcessStep)
                description:  Once all data was refracted by flight line data was exported to LAS 1.4 format and combined into 500 m x 500 m tiles. Data were then further calibrated using TerraMatch. NV5 used custom algorithms in TerraScan to classify the initial ground/submerged topography surface points. Relative accuracy of overlapping swaths was compared and verified through the use Delta-Z (DZ) orthos created using NV5's Las Product Creator. Absolute vertical accuracy of the calibrated data was assessed using ground survey data and complete coverage was again verified. Post automated classification NV5 then performed manual editing to review all classification and improve the final topobathymetric surface. NV5's LasMonkey was used to update LAS header information, including all projection and coordinate reference system information. The final lidar data are in LAS format 1.4 and point data record format 6. 1 - unclassified 2 - ground 7 - noise 40 - bathymetric bottom or submerged topography 41 - water surface 43 - submerged feature 45 - water column 46 - overlap bathy bottom - temporally different from a separate lift 71 - unclassified associated with areas of overlap bathy bottom/temporal bathymetric differences 72 - ground associated with areas of overlap bathy bottom/temporal bathymetric differences 81 - water surface associated with areas of overlap bathy bottom/temporal bathymetric differences 85 - water column associated with areas of overlap bathy bottom/temporal bathymetric differences 1 Overlap - edge clip 1 Withheld- green sensor returns within topographic areas 42 Synthetic - synthetic water surface
                dateTime:
                  DateTime:  2021-07-08T00:00:00
            processStep:  (LI_ProcessStep)
                description:  NV5 transformed the final lidar data from ellipsoid heights to orthometric heights referenced to NAVD88, Geoid 12b to create the final topobathymetric void clipped DEMs. The topobathymetric bare earth DEMs were output at 1 meter resolution in GeoTIFF format. The rasters are clipped to the extent of the project boundary and named according to project specifications. A bathymetric void shapefile was created to indicate areas where there was a lack of bathymetric returns. This shape was created by triangulating bathymetric bottom points with an edge length maximum of 4.56m to identify all areas greater then 9 square meters without bathymetric returns. This shapefile was used to clip and exclude interpolated elevation data from these areas in the bathymetric void clipped topobathymetric bare earth model.
                dateTime:
                  DateTime:  2021-07-08T00:00:00
            processStep:  (LI_ProcessStep)
                description:  The NOAA Office for Coastal Management (OCM) received files in IMG format. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. Converted from IMG to GeoTiff
                dateTime:
                  DateTime:  2021-10-08T00:00:00
                processor:  (CI_ResponsibleParty)
                    organisationName:  Office for Coastal Management
                    role:  (CI_RoleCode) processor
            source:  (LI_Source)
                sourceCitation:  (CI_Citation)
                    title:  Acquisition and Processing
                    date: (missing)
                    citedResponsibleParty:  (CI_ResponsibleParty)
                        organisationName:  NV5 Geospatial (NV5)
                        role:  (CI_RoleCode) originator