3 posts
Compute height above nearest drainage (HAND) from the Environment Agency LIDAR DTM at 5 m with pysheds, turn it into inundation extents for a range of stage heights on the River Severn between Shrewsbury and Buildwas, relate them to the Buildwas gauge, and score them honestly against the Environment Agency Flood Map for Planning with the hit rate, false-alarm ratio and critical success index.
Run a viewshed analysis in Python on a real DEM: compute what one wind turbine can see with gdal.ViewshedGenerate, rebuild the same line-of-sight algorithm in numpy, correct for earth curvature and refraction, build a cumulative zone of theoretical visibility (ZTV) from 26 turbines, draw line-of-sight profiles, and measure how much trees and buildings in a LiDAR DSM shrink a bare-earth viewshed.
Stream free USGS 3DEP lidar of Washington, D.C., read and inspect a LAZ file with laspy, remove noise, grid the points into a 1 m DTM, DSM and canopy height model, and use the result to measure the Washington Monument to within 44 cm.