LAS Files

These are ASPRS LAS v1.1-format files, developed as part of the City of New York's Department of Environmental Protection (DEP)'s year-2009 LiDAR data acquisition.  The project was set up to deliver LIDAR data suitable for updating FEMA digital flood maps. The project was expanded from city water supply watershed areas only, to cover the entire County of Westchester, NY.  In addition to these LAS files, the project also produced a new 3-meter-accuracy Digital Elevation Model, terrain data, and four-band one-foot-resolution imagery (R,G,B, and Infrared) covering all of Westchester. Each file covers 750m by 750 m on the ground.  Horizontal Datum is UTM, NAD 83, zone 18 N.  Vertical Datum is NAVD88.

The majority of the collection was completed between April 16, 2009 and June 25, 2009, but re-flights were completed on November 29, 2009 and December 2, 2009 to fill data gaps due to flight issues and leaf-cover.

These LAS files contain X, Y, and Z information as well as minimal classifications:  class 1 = unclassified (noise, etc.); class 2 = bare earth; class 7 = low points; class 12 = overlap points.  These data may be used for 3-d visualization, to develop 3-d models of the ground or surface, and for planning & preliminary engineering applications.

Meets ASPRS standards for LiDAR datasets.  Collected at a nominal point spacing and horizontal accuracy of 1.0 meters.

Meets ASPRS standards for LiDAR datasets.  Vertical accuracy of 18.5 centimeters RMSE or better.