National Land Cover Database 2011 - Tree Canopy (NLCD2011)

References

Coulston, J. W., Moisen, G. G., Wilson, B. T., Finco, M. V., Cohen, W. B., Brewer, C. K., Modeling percent tree canopy cover—A pilot study: Photogrammetric Engineering and Remote Sensing, v. 78, no. 7, p. 715–727, at https://doi.org/10.14358/PERS.78.7.715