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Showing posts from July, 2022

Featured Collection: Illinois Height Modernization (ILHMP): LiDAR Data

By Wenjie Wang, GIS Specialist at the University of Illinois Urbana-Champaign    Height Modernization (ILHMP) LiDAR Data [Illinois])     What is the item?  ILHMP has established data sharing agreements to archive and distribute elevation data for select Illinois counties. Data have been acquired using Light Detection And Ranging (LiDAR) technology, in compliance with different contract specifications. Data are offered as originally deliver LAS tile or as the derivative product of DEM/DTM or DSM.  What BTAA Library submitted the item?  Illinois Geospatial Data Clearinghouse  Interesting tidbits  Historically, Digital Elevation Model (DEM) data for Illinois have been mainly based on 5- to 10-foot contour data. Large-scale, digital topographic maps are most common; many data resources contain elevation information acquired in the 1920s and 1930s. DEM data collections are now being developed