Methods:

This canopy closure raster was derived directly from the LiDAR derived canopy height model. That 3-foot resolution raster was produced from the winter, 2019 Quality Level 1 LiDAR point cloud (already ground classified) using Lastools in a multistep process. The processing steps were as follows:

• Create Tiles (lastile)

• Height Normalize the Point Cloud (lasheight)

• Classify Buildings (lasclassify)

• Clamp Buildings to 0 Ft. Normalized Height (las2las)

• Thin the Point Cloud (lasthin)

• Convert the Height Normalized Point Cloud to a DEM (las2dem)

Uses and Limitations:

The canopy closure raster depicts areas of woody canopy greater than 15 feet tall for each 3x3 foot raster cell across Marin County. The layer is useful for myriad vegetation and forest-related analysis and is an important input to the automated processes used to develop the Marin County fine scale vegetation map. However, this data product was produced based on a rapid, fully automated point cloud classification and was not manually edited. As such, it includes some ‘false positives’ – pixels with a canopy height in the raster that aren’t vegetation. These false positives include noise from water aboveground non-vegetation returns from bridge decks, powerlines, and edges of buildings.

Methods:

This canopy closure raster was derived directly from the LiDAR derived canopy height model. That 3-foot resolution raster was produced from the winter, 2019 Quality Level 1 LiDAR point cloud (already ground classified) using Lastools in a multistep process. The processing steps were as follows:

• Create Tiles (lastile)

• Height Normalize the Point Cloud (lasheight)

• Classify Buildings (lasclassify)

• Clamp Buildings to 0 Ft. Normalized Height (las2las)

• Thin the Point Cloud (lasthin)

• Convert the Height Normalized Point Cloud to a DEM (las2dem)

Uses and Limitations:

The canopy closure raster depicts areas of woody canopy greater than 15 feet tall for each 3x3 foot raster cell across Marin County. The layer is useful for myriad vegetation and forest-related analysis and is an important input to the automated processes used to develop the Marin County fine scale vegetation map. However, this data product was produced based on a rapid, fully automated point cloud classification and was not manually edited. As such, it includes some ‘false positives’ – pixels with a canopy height in the raster that aren’t vegetation. These false positives include noise from water aboveground non-vegetation returns from bridge decks, powerlines, and edges of buildings.