Austin Lidar Project

Roberto Gutierrez, principal investigator; Rebecca C. Smyth, Tiffany L. Hepner, and Christopher Weed (Center for Space Research, The University of Texas at Austin)

Because of recurring flooding, Austin, Texas, needs new flood-hazard rate maps for the south part of the municipality. The City of Austin asked the Bureau to collect elevation data over the Williamson and Onion Creek watersheds using the Bureau's airborne lidar mapping system. Airborne lidar mapping uses a powerful laser scanning system and Global Positioning System (GPS) to measure the Earth's topography with great precision from a fixed- or rotary-winged aircraft.

In May 2002, researchers, working with the Texas State Aircraft Pooling Board, collected approximately 260 million lidar measurements over 92 mi2 of the city. Flood-hazard analysis requires an accurate representation of the ground surface and the stream network free of trees and buildings and necessitates classification of lidar topographic points. Using computer algorithms developed by the Center for Space Research, we identified the Austin lidar data as reflections from the ground, buildings, or vegetation. Classified lidar data thus provide detailed information for hydrologic, geologic, and environmental investigations.

For more infomation, please contact Jeff Paine. Telephone 512-471-1260; e-mail
February 2003