ARROWSMITH, Ramón, School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, CROSBY, Christopher J., UNAVCO, 6350 Nautilus Drive, Boulder, CO 80301 and NANDIGAM, Viswanath, San Diego Supercomputer Center, University of California, San Diego, MC 0505, 9500 Gilman Drive, La Jolla, CA 92093-0505

OpenTopography (OT) democratizes access to topographic data, services, and knowledge, enabling fundamental discoveries and innovative applications. OT focuses on improved data access using best practices in cyberinfrastructure and geoinformatics. We deliver topographic data (laser, radar, and photogrammetry) at a range of scales. We enable efficient access to global raster data (30-100 m/pix), but our emphasis has always been high-resolution topography (HRT; <1m/pix or >1 sample/sq. meter). OT currently holds 274 lidar point cloud datasets covering ~217,000 km2. More than a trillion points are available for on-demand processing and download. This is a considerable investment in HRT, valued at greater than $30 million, and represent the efforts of the NSF research community, public agencies, and international partners. OT distributes these data at various product levels at no cost to users, saving time and driving scientific innovation and broader impacts. OT has over 22,000 unique visitors per month, and almost 75,000 unique users have accessed data and processing services via OT. In 2017, 66,061 browser-based jobs were run with another 33,344 jobs via API calls. These computations and analyses support substantial academic, educational, and applied use and reuse of the valuable OT data holdings. OT exemplifies domain cyberinfrastructure evolving to become a production data facility upon which researchers, educators, and many others rely. Our partners depend on OT for data management because of our efficient distribution of data to a wide and diverse community of users, thus increasing the impact and return on investment of the data. OT supports tiered data access including lightweight network linked kmz hillshades all the way to custom derived topographic products such as drainage network properties and solar insolation distributions (for global datasets). Newly implemented browser based visualization of point cloud datasets enables rich 3D interactions without the need to download data or additional software tools. OT is built on open source software, and actively contributes to such efforts.