High Density LiDAR of the 2018 Volcanic Eruption
The 2018 Kilauea volcanic eruption began May 3rd, 2018. The ensuing lava flows destroyed infrastructure and property over large areas of the southwest corner of the Island of Hawaii. As lava flows spread to reach the ocean, the island has been transformed resulting in new topography. For emergency responders and scientists, understanding this new topography is vital for planning future scenarios which may impact residents. The United States Geologic Survey (USGS) Hawaiian Volcano Observatory (HVO), along with emergency responders, government agencies and academics recognized that the use of airborne Lidar remote sensing surveys would be a valuable tool for understanding the effects of active volcanic eruptions. The methods to deploy such a survey require careful planning and the ability to adapt to on-site conditions while managing safety. Working with USGS NGTOC, Quantum Spatial Inc (QSI) was tasked to rapidly collect and process high density Lidar data covering five distinct locations, covering an area of 57 square miles, including the Kilauea Summit Caldera, Pu’u O’o Crater and the Western Leilani Estates lava field. Within days the aviation, sensor operations, and processing team was on-site. Simultaneously to the site mobilization, QSI flight managers worked with USGS scientists and aviation experts to plan flight operations considering wind direction, volcanic activities, contingency planning, and real-time process requirements. Data was acquired at point densities averaging from 40 to 80 ppsm, with up to 150 ppsm in select areas along with 100mp digital imagery using a Riegl dual VUX-1 LR sensor pod equipped with ABGPS/IMU mounted on a Hughes 500D helicopter. The project required 11 missions over the course of six days, operating, at times, as low as 500 feet above the ground and above active flows and nearby erupting calderas. With a need for a quick turnaround, QSI deployed an analyst with the flight crew to post process each mission within hours of collection. The data was uploaded to the Geospatial Repository and Data Management System (GRiD) interface, developed by the U.S. Army Corps of Engineers (USACE), where additional data products have been developed and provided to the response team that includes FEMA, Hawaii?s Emergency Operations Center (EOC), and the Hawaii County Civil Defense. Some notable aspects of this project pertain to the adaptability required by pilots, operators, and processors in order to successfully complete project objectives. Communication between scientists and crews was extremely valuable, as pilots were required to consider weather conditions, volcanic activity, wind direction, and restricted air space. Communication with USGS scientists, whom had intimate knowledge of site conditions, was required for success. On the processing side of the project, QSI processors conferred with survey specialists, scientists, and sensor operators to understand the nature of the data as it was being processed. This assisted the processing effort in understanding sensor noise, ground movement, and change within the data to calibrate a dynamic dataset in a short time window.