2010 USACE NCMP Topobathy Lidar: Northeast Atlantic Coast (CT, MA, ME, NH, RI)

These files contain topographic lidar and bathymetric data classified as ground (2), unclassified (1), and NOAA OCM bathymetry (11) in accordance with the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards. Rejected or invalid data is classified as noise (7). These data were collected by a HawkEye II (HEII) lidar sensor. The HEII integrates topographic and bathymetric lidar sensors, and a digital camera on a single remote sensing platform for use in coastal mapping and charting activities. Native lidar data is not generally in a format accessible to most Geographical Information Systems (GIS). Specialized in-house

and commercial software packages are used to process the native lidar data into 3D positions that can be imported into GIS software for visualization and further analysis. Horizontal positions, provided in decimal degrees of latitude and longitude, are referenced to the North American Datum of 1983 (NAD83). For the topographic data, vertical positions were acquired to the NAD83 ellipsoid. The National Geodetic Survey's (NGS) GEOID09 model was used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88). The bathymetry files for this data set were received by NOAA OCM after the initial topographic files. The bathymetry files were added to the existing topographic data set. The bathymetry files were received in csv format and in geographic coordinates, referenced to the North American Datum of 1983 (NAD83). They were in ellipsoid heights, in meters. For data storage and Digital Coast provisioning, the NOAA OCM converted the topographic files to ellipsoid heights and the bathymetry files to las format. The bathymetry files were also classified as 11 (NOAA OCM bathymetry). The 3D position data are sub-divided into a series of files each covering approximately 5 kilometers of shoreline.

In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record.

Original contact information:

Contact Org: JALBTCX

Title: Data Production Manager

Phone: 228-252-1121

Email: JALBTCX@usace.army.mil

These data were collected as a part of the NCMP to depict the elevations above and below the water in the coastal zone of Rhode Island, Massachusetts,

New Hampshire, Connecticut, and Maine.

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A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1174/supplemental/2010_USACE_JALBTCX_Northeast_Lidar.kmz

Any conclusions drawn from the analysis of this information are not the responsibility of JALBTCX, the Office for Coastal Management or its partners.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer;

None

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.

Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog 9.3.0.1770

The data positions were obtained using post processed inertially aided KGPS methods. The horizontal accuracy of the data is better than 0.50m RMSE.; Quantitative Value: 0.98 meters, Test that produced the value: Accuracy based on 1.96 X RMSE.

The data positions were obtained using post processed inertially aided KGPS methods. Tested 0.172m fundamental vertical accuracy at 95 percent

confidence level in open terrain using RMSEz x 1.9600. Tested 0.270m supplemental vertical accuracy at 95th percentile in short grass. Tested 0.553m

supplemental vertical accuracy at 95th percentile in tall grass. Tested 0.640m supplemental vertical accuracy at 95th percentile in brush/canopy.

; Quantitative Value: 0.172 meters, Test that produced the value: Tested fundamental vertical accuracy at 95 percent confidence level in open terrain.

None provided

The data provided in this file were tested against ground truth data. Tested 0.172m fundamental vertical accuracy at 95 percent confidence level

in open terrain using RMSEz x 1.9600.

The USACE collected, processed, and provided the data to the NOAA Office for Coastal Management (OCM). OCM received the data and processed it to be available for custom download from the Data Access Viewer (DAV) and for bulk download from https.