Lidar (Light Detection and Ranging), a remote sensing tool that uses pulses of light to measure the elevation of reflecting surfaces, was used to acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments, and hydrologic modeling. LAS and bare earth DEM data product s are suitable for 1 foot contour generation.
Discrete return lidar data were collected during leaf-off conditions in the spring of 2015 as part of the Michigan Statewide Authoritative Imagery & Lidar (MiSAIL) program. The Sanborn Map Company was tasked by the State of Michigan to deliver high point density returns with Nominal Point Spacing of 0.71 m. Data were collected using a Leica ALS80 sensor flown on board an aircraft at an altitude of approximately 1200 m with a maximum scan angle of 32 degrees. Lidar acquisition was in compliance with Quality Level 2 of the United States Geologic Survey (USGS) National Geospatial Program (NGP) Base Lidar Specifications ; horizontal accuracy of non-vegetation returns were better than 1 m and vertical accuracy of non-vegetation returns was 0.029 m. The lidar output standard for MiSAIL is a one meter Digital Terrain Model (DTM) which would leave relevant microtopograpic features unidentifiable. We found that, in fact, the resulting lidar data were suitable for generation of 1 foot contours (0.305 meter) (which we acquired as an LAS Dataset which is the industry-standard binary format for storing airborne lidar data).
Data Access: https://umich.box.com/v/UMBS2015LiDAR (data file storage constraints within UMBS Research Gateway necessitate use of cloud storage)