Digital Terrain Model (DTM) from 2005 LiDAR for the Green Lakes Valley, Colorado

This 1m Digital Terrain Model (DTM) is derived from bare-ground Light Detection
and Ranging (LiDAR) point cloud data from September 2005 for the Green Lakes Valley,
near Boulder Colorado. This dataset is better suited for derived layers such as
slope angle, aspect, and contours. The DTM was created from LiDAR point cloud tiles
subsampled to 1-meter postings, acquired by the National Center for Airborne Laser
Mapping (NCALM) project. This data was collected in collaboration between the
University of Colorado, Institute of Arctic and Alpine Research (INSTAAR) and NCALM,
which is funded by the National Science Foundation (NSF). The DTM has the
functionality of a map layer for use in Geographic Information Systems (GIS) or
remote sensing software. Total area imaged is 35 km^2. The LiDAR point cloud data
was acquired with an Optech 1233 Airborne Laser Terrain Mapper (ALTM) and mounted in
a twin engine Piper Chieftain (N931SA) with Inertial Measurement Unit (IMU) at a
flying height of 600 m. Data from two GPS (Global Positioning System) ground
stations were used for aircraft trajectory determination. The continuous DTM surface
was created by mosaicing and then kriging 1 km2 LiDAR point cloud LAS-formated tiles
using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy and vertical
accuracy is unknown. The layer is available in GEOTIF format approx. 265 MB of data.
It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical
datum computed using NGS GEOID03 model, with FGDC-compliant metadata. A shaded
relief model was also generated. A similar layer, the Digital Surface Model (DSM),
is a first-stop elevation layer. A processing report and readme file are included
with this data release. The DTM is available through an unrestricted public license.
The LiDAR DEMs will be of interest to land managers, scientists, and others for
study of topography, ecosystems, and environmental change. NOTE: This EML metadata
file does not contain important geospatial data processing information. Before using
any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC
compliant format, using ArcGIS software (ArcCatalog > description), or by viewing
the .xml file provided with the geospatial dataset.