Overview

In most organizations, lidar data is part of a larger data management effort that includes other elevation data. Some projects require analysis of the lidar data in 3D point format, but nearly all lidar projects share a need for elevation surfaces such as a bare-earth digital terrain model (DTM) and first-return digital surface model (DSM). A key requirement is fast access for visualization and analysis of elevation surfaces to support a variety of workflows.

Representations such as hillshade and slope are often required, and the raster surfaces can be used for fast viewshed and volumetric analysis. The elevation data within an organization will typically come from many different projects, in some cases with the same area covered by multiple data collections. The generation of rasters from lidar is therefore a primary aim of this workflow.

The other common requirement is the serving of lidar point clouds, or enabling users to download the lidar points for detailed analysis. As an alternative to users downloading the point clouds, it may be more optimal to serve geoprocessing tools that utilize the underlying 3D points in an analysis task and return the required results served. This workflow also provides details of how this can be achieved.

There are four stages to this workflow, with optional fifth and sixth stages:

• Managing your separate lidar collections using LAS datasets
• Determining parameters to create raster files
• Creating derived rasters for visualization and analysis—the bare-earth DTM and first-return DSM
• Creating mosaic datasets and serving the raster data
• Enabling download of the lidar point files, if desired (optional)
• Building and sharing geoprocessing services for server-side analysis, if desired (optional)

The recommended workflow for processing and managing lidar data within ArcGIS includes many steps in common with the recommended best practices for elevation data. As such, this document describes only the lidar-specific details as required, and otherwise refers to the existing elevation workflow as described in the Image Management guidebook for a complete discussion.

The recommendations in this document have been implemented in example scripts available for download and user modification in the ArcGIS Image Management Workflows group on ArcGIS Online. It is recommended that the Elevation scripts and sample data be downloaded and reviewed in conjunction with this document, as they provide examples.