San Francisco Bay Digital Elevation (DEM)

Several methods to correct lidar elevation data are available, but a reliable method that requires limited fi eld work and maintains high spatial resolution was lacking. In a paper published in 2016, USGS presented a novel method, the Lidar Elevation Adjustment with NDVI (LEAN), to correct lidar digital elevation models (DEMs) with vegetation indices from readily available multispectral airborne imagery (NAIP) and fi eld real-time kinematic (RTK)-GPS elevation surveys. By using available imagery and with fi eld RTK GPS elevation surveys, the paper showed that lidar-derived DEMs can be adjusted with greater accuracy while maintaining high (1 m) resolution.