Lidar Sources and Software
Lidar Data
Lidar data is usually delivered as a point cloud. The most common file formats are LAS formats and the ASCII text format. In the ASCII format, the coordinates for each point are stored in a text file separated by commas. The LAS format is the standard lidar data exchange format that is maintained by the American Society for Photogrammetry and Remote Sensing (ASPRS). LAS is the preferred format if available, as it is efficient and non-proprietary. LAZ is the compressed version of LAS. LAZ files are much smaller than LAS but must be uncompressed before they can be used.
Lidar Data Sources
Lidar is still relatively expensive to acquire, although costs are beginning to decline. The first acre of a lidar flight is expensive, due to the costs of the aircraft, equipment, and personnel. But when large areas are covered, the costs can drop to about $1 to $2 per acre. There are some sources of free, public domain lidar datasets.
Open Topography
Open Topography is the public domain where users upload their data for public to have access of high quality topographic and bathymetry data. Open Topography system is based on the San Diego Supercomputer center at the University of California. The Open Topography YouTube Channel is a good resource for lidar examples and tutorials.
EarthExplorer
USGS provide free lidar data of the USA through Earth Explorer. The Iidar data can be found under the "Digital Elevation" Data Sets by selecting "LIDAR".
The National Map
To respond to growing needs for high-quality elevation data across the United States, the U.S. Geological Survey 3D Elevation Program (3DEP) is systematically completing acquisition of nationwide lidar by 2023 to provide the first-ever national baseline of consistent high-resolution elevation data – both bare earth and 3D point clouds – collected in a timeframe of less than a decade.
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration (NOAA) has large lidar data sets of the USA coastal regions. The data is available through the NOAA Digital Coast website. Lidar and other coastal data is available for download the data through the web map data viewer.
Software
ArcGIS
ArcGIS can be used to create digital surface models from points clouds, including DEMs and CHMs. ArcGIS reads LAS files formats and provides a LAS Toolbar to filter and manipulate LAS files. ArcScene can be used to display LAS datasets in 3D. You can also drape imagery and add additional layers and measure 3D distances in ArcScene.
ENVI
ENVI offers a special extension, ENVI LiDAR that is specifically designed to view and analyze lidar data. ENVI LiDAR provides 3-rendering, 3-D feature extraction and analysis. ENVI LiDAR is an additional package that does not come standard with ENVI and must be purchased separately.
FUSION
FUSION is a Lidar viewing and analysis software tool developed by the Silviculture and Forest Models Team, Research Branch of the US Forest Service. FUSION is Free! FUSION can be used to view and analyze lidar data. Digital surface models can be generated, data can be sampled and metric can be calculated from point clouds. FUSION can be downloaded though the USFS Pacific Northwest Research Station. Tutorials are also available.
Online Point Cloud Viewer
There are many Online Point Cloud Viewers that allow you to upload lidar data sets and visualize the data. The are an excellent resource to quickly view a lidar dataset, although the viewer don't allow for any analysis. One such viewer is lidarview.com where you can upload LAS data set and view and animate the point clouds.
