Connecticut Statewide Lidar DEM 2016

Metadata also available as

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: State of Connecticut
Originator:
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Office for Coastal Management (OCM)
Publication_Date: 20171020
Title: Connecticut Statewide Lidar DEM 2016
Edition: 1.0
Geospatial_Data_Presentation_Form: point digital data (LAS)
Publication_Information:
Publication_Place: Charleston, SC
Publisher: NOAA's Ocean Service (NOS), Office for Coastal Management (OCM)
Online_Linkage: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8396
Online_Linkage:
https://coast.noaa.gov/htdata/raster2/elevation/CT_statewide_DEM_2016_8396
Online_Linkage: https://coast.noaa.gov/dataviewer
Online_Linkage: https://coast.noaa.gov
Online_Linkage: http://crcog.org
Description:
Abstract:
This metadata record describes the hydro-flattened bare earth digital elevation model (DEM) derived from the classified LiDAR data for the 2016 Connecticut Lidar project covering approximately 5,240 square miles.
Purpose:
To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments, and hydrologic modeling. LAS data products are suitable for 1 foot contour generation. USGS Lidar Base Specification 1.2, QL2. 19.6 cm NVA.
Supplemental_Information:
Project Projection, Datums and Units: Projection - State Plane Connecticut; Horizontal datum - North American Datum of 1983 (NAD83 (2011)); Vertical datum - North American Vertical Datum of 1988 (NAVD88) using the latest geoid (Geoid12b) for converting ellipsoidal heights to orthometric heights; Units - US feet horizontal, meters vertical. This data was ingested into the Digital Coast Data Access Viewer for custom processing. If you requested this data through that system, your projection may be different and will be reflected below.
A data report is available at ftp://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8392/supplemental/Final_LiDAR_Report_CRCOG_2016.pdf
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20160311
Ending_Date: 20160416
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Unknown
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -73.745809
East_Bounding_Coordinate: -71.782632
North_Bounding_Coordinate: 42.063615
South_Bounding_Coordinate: 40.971166
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: oceans
Theme:
Theme_Keyword_Thesaurus: CT
Theme_Keyword: LiDAR
Theme_Keyword: mapping
Theme_Keyword: point cloud
Theme_Keyword: ground points
Theme_Keyword: Unclassified points
Theme_Keyword: Water points
Theme_Keyword: Overlap points
Theme_Keyword: ALS70
Theme_Keyword: LMS-Q680i
Theme_Keyword: Intensity return
Theme_Keyword: LAS
Theme_Keyword: Digital Elevation Model (DEM)
Theme_Keyword: Digital Terrain Model (DTM)
Theme_Keyword: IMG
Theme_Keyword: Grid
Theme_Keyword: Bare Earth
Theme_Keyword: First Return
Theme_Keyword: Contour
Place:
Place_Keyword_Thesaurus: CT
Place_Keyword: Connecticut
Place_Keyword: United States
Temporal:
Temporal_Keyword_Thesaurus: none
Temporal_Keyword: 2016
Access_Constraints:
This data may be used by the requesting party at their own risk and may be re-distributed.
Use_Constraints:
This data is for planning purposes only and should not be used for legal or cadastral purposes. Any conclusions drawn from analysis of this information are the responsibility of the user. Users should be aware that temporal changes may have occurred since this dataset was collected and some parts of this dataset may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA Office for Coastal Management
Contact_Address:
Address_Type: mailing and physical
Address: 2234 South Hobson Avenue
City: Charleston
State_or_Province: SC
Postal_Code: 29405-2413
Contact_Voice_Telephone: 843-740-1202
Contact_Electronic_Mail_Address: coastal.info@noaa.gov
Browse_Graphic:
Browse_Graphic_File_Name:
https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8392/supplemental/2016_ct_area.kmz
Browse_Graphic_File_Description: A polygon footprint of this data set.
Browse_Graphic_File_Type: kmz
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
State of Connecticut:
The LiDAR surface was evaluated using a collection of 181 GPS surveyed checkpoints for the raw NVA report. The DEM was compared to these checkpoints yielding a better result than was required for the project.
Raw NVA Control Accuracy Report (feet)
--------- Report Disclaimer ---------
This report does not guarantee accuracy. The report only reflects one statistical representation of the control points, LIDAR data and surface used. This report does not replace a thorough quality control process.
--------- Report Summary --------- Average dz 0.004 Minimum dz -0.829 Maximum dz 0.622 Average magnitude 0.170 Root mean square 0.227 Std deviation 0.228
----------------------------------------------------------------------------------------
Attribute accuracy is tested after the LiDAR processing stage. After classification of the LiDAR data, DEMs are created using the bare earth points. The NVA report is generated from the comparison of the DEM and the ground control collected within the project area.
The DEM surface was evaluated using a collection of 181 GPS surveyed checkpoints for the NVA report. The DEM was compared to these checkpoints yielding much better result than was required for the project.
NVA Control Accuracy Report (feet)
--------- Report Disclaimer ---------
This report does not guarantee accuracy. The report only reflects one statistical representation of the control points, LIDAR data and surface used. This report does not replace a thorough quality control process.
--------- Report Summary --------- Average dz 0.004 Minimum dz -0.778 Maximum dz 0.576 Average magnitude 0.158 Root mean square 0.207 Std deviation 0.207
----------------------------------------------------------------------------------------
Attribute accuracy is tested after the LiDAR processing stage. After classification of the LiDAR data, DEMs are created using the bare earth points. The VVA report is generated from the comparison of the DEM and the ground control collected within the project area.
The DEM was evaluated using a collection of 95 GPS surveyed checkpoints. The DEM was compared to these checkpoints yielding much better result than was required for the project.
VVA Control Accuracy Report (feet)
--------- Report Disclaimer ---------
This report does not guarantee accuracy. The report only reflects one statistical representation of the control points, LIDAR data and surface used. This report does not replace a thorough quality control process.
--------- Report Summary --------- Average dz 0.147 Minimum dz -0.771 Maximum dz 0.625 Average magnitude 0.212 Root mean square 0.261 Std deviation 0.217
----------------------------------------------------------------------------------------
Quantitative_Attribute_Accuracy_Assessment:
Attribute_Accuracy_Value: 0
Attribute_Accuracy_Explanation: N/A
Logical_Consistency_Report:
LiDAR data is collected within the project area and processed. After the DEMs were created, the dataset was verified against control. Well-distributed control was collected for the entire state of Connecticut. Accuracy is reported for the state as a whole.
Completeness_Report:
LiDAR data is collected for the project area. Post processing of the simultaneously acquired GPS/INS is performed and applied to the laser returns to output a point cloud in the specified project coordinate system and datums. The point cloud data is then subjected to automated classification routines to assign all points in the point cloud to ground, water, overlap and unclassified point classes. Anomalous laser returns that occur infrequently are removed entirely from the data set. Once clean bare earth points are established, DEMs are created using bare earth points and hydro features. The DEM surface is then compared to the survey checkpoints. These accuracies must pass the NVA and VVA accuracy specifications.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Horizontal positional accuracy for the Connecticut LiDAR is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 1.0 meter RMSEx/RMSEy.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 1.0
Horizontal_Positional_Accuracy_Explanation:
For the Connecticut, this value is computed by comparing ground control to a DEM derived from the classified LiDAR data and represents the RMSE of residuals on controls within the project area.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
For the DEM data derived from the classified point cloud, the NVA and VVA were computed. The vertical accuracy was tested with independent survey check points located in various terrain types within Connecticut. These check points were not used in the calibration or post processing of the lidar point cloud data. The survey check points were distributed throughout the block area. Specifications for this project require that the VVA be 19.6 cm or better @ 95 percent confidence level.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 0.070
Vertical_Positional_Accuracy_Explanation:
Value is RMSE in meters. The raw NVA was tested using 181 independent survey check points located in flat terrain types within the state of Connecticut The survey checkpoints were distributed throughout the block area. The 181 independent check points were surveyed using static GPS base stations collecting point location for 20 minute intervals. Elevations were measured for the x,y,z location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. This data set was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 7cm, equating to +/- 13.8cm at 95% confidence level.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 0.063
Vertical_Positional_Accuracy_Explanation:
Value is RMSE in meters. The NVA was tested using 181 independent survey check points located in bare earth terrain types within the state of Connecticut. The 181 independent check points contained all NVA points and were surveyed using static GPS base stations collecting point location for 20 minute intervals. Elevations were measured for the x,y,z location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. This data set was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 6.3cm, equating to +/- 12.5cm at 95% confidence level.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 0.080
Vertical_Positional_Accuracy_Explanation:
Value is RMSE in meters. The VVA was tested using 95 independent survey check points located in various vegetation terrain types within the state of Connecticut. The 95 independent check points were surveyed using static GPS base stations collecting point location for 20 minute intervals. Elevations were measured for the x,y,z location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. This data set was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 6.3cm, equating to +/- 12.5cm at 95% confidence level. Actual VVA accuracy was found to be +/- 17cm at the 95th percentile.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Sanborn Map Company Inc.
Publication_Date: Unknown
Title: LiDAR Data
Edition: 1.0
Geospatial_Data_Presentation_Form: Remote sensing image
Publication_Information:
Publication_Place: None
Publisher: None
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: LIDAR and GPS_RAW
Source_Contribution:
Aerial LiDAR and GPS/IMU data are recorded for the defined project area at an altitude, flight speed, scanner swath width and scanner pulse frequency to achieve the design goals of the project.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Sanborn Map Company Inc.
Publication_Date: 2010
Title: Ground control
Edition: 1.0
Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:
Publication_Place: None
Publisher: None
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: CONT
Source_Contribution:
Targeted ground control is used to create a digital control file and control report as well as QC check of LiDAR accuracy. Predefined points (NGS when available) within the project area are targeted.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Sanborn Map Company Inc.
Publication_Date: Unknown
Title: Post processed GPS/INS
Edition: 1.0
Geospatial_Data_Presentation_Form: Tabular digital data
Source_Scale_Denominator: 1200
Type_of_Source_Media: disk
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: GPS
Source_Contribution:
Post processed GPS/INS is applied to the lidar point data to georeference each point in the project coordinate system
Source_Information:
Source_Citation:
Citation_Information:
Originator: Sanborn Map Company Inc.
Publication_Date: Unknown
Title: Post processed lidar
Edition: 1.0
Geospatial_Data_Presentation_Form: Point digital data
Source_Scale_Denominator: 1200
Type_of_Source_Media: Disk
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: Lidar Processed
Source_Contribution:
The post processed lidar data has been projected and oriented in the specified coordinate system as an un-classified point cloud.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Sanborn Map Company Inc.
Publication_Date: Unpublished material
Title: Classified lidar
Edition: 1.0
Geospatial_Data_Presentation_Form: Point digital data
Source_Scale_Denominator: 1200
Type_of_Source_Media: disk
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: LAS
Source_Contribution:
The classified lidar point cloud is used to derive various data products such as, but not limited to, bare earth gridded DEM, triangulated irregular networks (TIN), contours, digital surface models (DSM). The output format is fully compliant LAS v1.4, Point Record Format 6
Source_Information:
Source_Citation:
Citation_Information:
Originator: State of Connecticut
Publication_Date: Unpublished material
Title: Tile Definition
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Source_Scale_Denominator: 1200
Type_of_Source_Media: disk
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2016
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: TLDEF
Source_Contribution:
The tile definition defines discreet non-overlapping rectangular areas used as cut lines to break up the large classified lidar dataset into smaller, more manageable data tiles. Each tile is 2500ft by 2500ft in dimension.
Process_Step:
Process_Description:
At selected locations throughout the site, accurate GPS coordinates and elevations are surveyed and the points are marked with targets.
Process_Date: 2016
Source_Produced_Citation_Abbreviation: CONT
Process_Step:
Process_Description:
New LiDAR data is captured for the project area using a Leica ALS70 LiDAR instrument an integrated IPAS20 GPS/INS system mounted within a Aero Commander twin engine airplane.
Process_Date: 2016
Process_Step:
Process_Description:
The airborne GPS data is post-processed in Inertial Explorer software and LEICA CloudPro software to determine the LiDAR sensor's angle and orientation in the terrain (project) coordinate system and datums during the survey.
Process_Date: 2016
Process_Step:
Process_Description:
The post processed GPS/INS solution is applied to the raw lidar data to orient and project the data points into the project area reference system as an unclassified point cloud.
Process_Date: 2016
Source_Produced_Citation_Abbreviation: LAS
Process_Step:
Process_Description:
The georeferenced lidar data is then classified and edited in Terrasolid Terrascan software. Data is classified to produce: Class 1: unclassified, Class 2: ground, Class 7: low point, Class 9: water, Class 10: ignored ground, Class 17: bridge deck, Class 18: high noise.
Process_Date: 2016
Source_Produced_Citation_Abbreviation: LAS
Process_Step:
Process_Description:
The classified lidar data is exported as 2500 X 2500 foot tiles in the LAS format with any or all classes required to produce derivative products.
Process_Date: 2016
Source_Produced_Citation_Abbreviation: LAS
Process_Step:
Process_Description:
The NOAA Office for Coastal Management (OCM) received the files in las 1.4 format. The files contained Lidar elevation and intensity measurements. The data were in Connecticut State Plane (NAD83 2011 Epoch 2010.0; FIPS 0600), US Feet coordinates and NAVD88 (Geoid12b) vertical feet. OCM performed the following processing to the data to make it available within the Digital Coast: 1. The data were converted from Connecticut State Plane coordinates to geographic coordinates. 2. The vertical units of the data were converted from feet to meters. 3. The data were converted from NAVD88 (orthometric) heights to NAD83(2011) ellipsoid heights using Geoid12b grids. 4. Data were compressed with laszip as native LAS 1.4.
Process_Date: 201710
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA Office for Coastal Management
Contact_Address:
Address_Type: mailing and physical
Address: 2234 South Hobson Avenue
City: Charleston
State_or_Province: SC
Postal_Code: 29405-2413
Contact_Voice_Telephone: 843-740-1202
Contact_Electronic_Mail_Address: coastal.info@noaa.gov
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: NAD_1983_2011_State_Plane_Connecticut_FIPS_0600
Lambert_Conformal_Conic:
Standard_Parallel: 41.2
Standard_Parallel: 41.8666666666667
Longitude_of_Central_Meridian: -72.75
Latitude_of_Projection_Origin: 40.8333333333333
False_Easting: 999999.999996
False_Northing: 499999.999998
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 2
Ordinate_Resolution: 2
Planar_Distance_Units: survey feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983 (2011)
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222101004
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988(GEOID12b)
Altitude_Resolution: 0.01
Altitude_Distance_Units: meters
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Bare Earth only
Classes: 2 - Bare-Earth Ground
Entity_and_Attribute_Detail_Citation: USGS Base Specification 1.2, QL2 meeting 19.6 cm NVA
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA Office for Coastal Management
Contact_Address:
Address_Type: mailing and physical
Address: 2234 South Hobson Avenue
City: Charleston
State_or_Province: SC
Postal_Code: 29405-2413
Contact_Voice_Telephone: 843-740-1202
Contact_Electronic_Mail_Address: coastal.info@noaa.gov
Resource_Description: Connecticut 2016 LiDAR project
Distribution_Liability:
The Capitol Region Council of Governments digital data have been tested and their documentation carefully reviewed. However, the Capitol Region Council of Governments and its representatives make no warranty or representation, either expressed or implied, with respect to the digital data and their documentation, their quality, performance, merchantability, or fitness for a particular purpose. The digital data are distributed on "as is" basis, and the user assumes all risk to their quality, the results obtained from their use, and the performance of the data. In no event will the Capitol Region Council of Governments or its representatives be liable for any direct, indirect, special, incidental or consequential damages resulting from and defect in the State of Connecticut or in their documentation. This disclaimer of warranty is exclusive and in lieu of all others, oral or written, express or implied. No agent or employee is authorized to make any modification, extension, or addition to this warranty.
Any conclusions drawn from the analysis of this information are not the responsibility of the Capitol Region Council of Governments, the Office for Coastal Management or its partners.
Metadata_Reference_Information:
Metadata_Date: 20171005
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Shawn Benham
Contact_Organization: Sanborn Map Co
Contact_Position: Project Manager
Contact_Address:
Address_Type: mailing address
Address: 1935 Jamboree Dr
City: Colorado Springs
State_or_Province: CO
Postal_Code: 80920
Country: U.S.A.
Contact_Voice_Telephone: 719.502.1296
Contact_Electronic_Mail_Address: sbenham@sanborn.com
Hours_of_Service: 8:00 AM - 5:00 PM
Metadata_Standard_Name: FGDC CSDGM
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Security_Information:
Metadata_Security_Classification_System: None
Metadata_Security_Classification: Unclassified
Metadata_Security_Handling_Description: None
Generated by mp version 2.9.32 on Thu Oct 5 15:31:57 2017