2012 USACE Topobathy Lidar DEM: Post Sandy (NJ & NY)

These files contain a digital elevation model derived from lidar data. The lidar data were collected on November 16, 2012 and cover

portions of the following counties:

New Jersey - Bergen, Essex, Hudson, Middlesex, Monmouth, Ocean, Union

New York - Bronx, Kings, Nassau, New York, Queens, Richmond, Suffolk, Westchester

These data were collected by the Coastal Zone Mapping and Imaging Lidar (CZMIL) system. CZMIL integrates a lidar sensor with

topographic and bathymetric capabilities, a digital camera and a hyperspectral imager 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 Geographic

Information Systems (GIS). Specialized in-house and commercial software packages are used to process the native lidar data

into 3-dimensional 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). Vertical

positions are referenced to the NAD83 ellipsoid and provided in meters. The National Geodetic Survey's (NGS) GEOID12A model

is used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical

Datum of 1988 (NAVD88).

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 Post Sandy effort to depict the elevations above and below the water in the NY coastal zone.

In areas of dense vegetation the points classified as ground might be incorrectly classified due to the inability of the laser to

penetrate the canopy and reach the bare ground.

Any conclusions drawn from the analysis of this information are not the responsibility of USACE,

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/#/lidar/search/where:ID=2478

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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this data may no longer represent actual surface conditions.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

These data are not attributed. | Quantitative Value: N/A | Quantitative Test Explanation: These data are not attributed.

The data positions were obtained using post processed KGPS methods. The horizontal accuracy of the data is better

than plus or minus 0.75 m.

; Quantitative Value: 0.75 meters, Test that produced the value: RMSE 95% Conf.

The data positions were obtained using post processed KGPS methods. The vertical

accuracy of the data is 0.125 m RMSE.

; Quantitative Value: 0.125 meters, Test that produced the value: RMSE 95% Conf.

Cloud Cover: Unknown

This data set covers the spatial extent of bathymetric and topographic lidar data obtained during this survey.

Differences between a DEM created from the lidar data representing bare ground and the ground truth

data is unbiased and measures 0.0396 m RMSE.