Bevis, M.G., Hudnut, K.W., Sanchez, R.D., Toth, C.K., Grejner-Brzezinska, D.A., Kendrick, E.C., Caccamise, D.J., Raleigh, David, Zhou, Hao, Shan, Shan, Shindle, W.M., Yong, A.K., Harvey, J.C., Borsa, A.A, Ayoub, Francois, Shrestha, R.L., Carter, W.E., Sartori, M.P., Phillips, D.A., Coloma, Francine, and DeLong, S.B., 2017, Classified point cloud and gridded elevation data from the 2005 B4 Lidar Project, southern California, USA: U.S. Geological Survey data release, https://doi.org/10.5066/F7TQ5ZQ6.
These data are derived from the original 2005 B4 lidar data collected over the southern San Andreas and San Jacinto fault zones in southern California, USA. These data been a fundamental resource for study of active faulting in southern California since they were released in 2005. The 2005 data were not released as classified points that allowed for easy differentiation between bare ground surfaces and the objects and vegetation above that surface. This data release consists of the original data with new point classification added to each point. These data were originally collected to provide the first high resolution topographic data available along the southern San Andreas and San Jacinto fault systems in southern California. More specifically, the original data were collected with the following intent (quoted from the abstract of NSF Award 0409045): "To image the fault system in great detail prior to the next great earthquake, i.e. the 'Big One', so that when this event occurs it will be possible to map the near-field displacement and deformation field with unprecedented accuracy. Post-event resurveys of the fault system will determine slip and afterslip heterogeneity, and so help resolve several long-standing debates in earthquake source physics. It will also be possible to characterize near-field deformation associated with the along-strike transition from continuously-creeping to fully-locked sections of the San Andreas Fault". Dataset Overview: “The B4 Lidar Project collected lidar point cloud data of the southern San Andreas and San Jacinto Faults in southern California. Data acquisition and processing were performed by the National Center for Airborne Laser Mapping (NCALM) in partnership with the USGS and Ohio State University through funding from the EAR Geophysics program at the National Science Foundation (NSF). Optech International contributed the ALTM3100 laser scanner system. UNAVCO and SCIGN assisted in GPS ground control and continuous high rate GPS data acquisition. A group of volunteers from USGS, UCSD, UCLA, Caltech and private industry, as well as gracious landowners along the fault zones, also made the project possible. If you utilize the B4 data for talks, posters or publications, we ask that you acknowledge the B4 project. The B4 logo can be downloaded here.” Dataset Acknowledgement: “The B4 Lidar Project collected lidar point cloud data of the southern San Andreas and San Jacinto Faults in southern California. Data acquisition and processing were performed by the National Center for Airborne Laser Mapping (NCALM) in partnership with the USGS and Ohio State University through funding from the EAR Geophysics program at the National Science Foundation (NSF). Optech International contributed the ALTM3100 laser scanner system. UNAVCO and SCIGN assisted in GPS ground control and continuous high rate GPS data acquisition. A group of volunteers from USGS, UCSD, UCLA, Caltech and private industry, as well as gracious landowners along the fault zones, also made the project possible.” The purpose of these classified data is to increase the value and ease of use by providing classified point clouds and derivative gridded products to the scientific community. The data release includes classified point clouds, half-meter-resolution bare-Earth digital elevation models and hillshades, and meter-resolution full-feature digital elevation models and hillshades.
