G-LiHT | Off to a Flying StartJuly 17th, 2014 by Kathryn Hansen
Text and photos provided by Doug Morton
NASA’s Goddard Space Flight Center
NASA and USDA Forest Service scientists are collaborating on an ambitious project to inventory forest resources in the Tanana Valley of interior Alaska, a region the size of Iowa. The pilot project, funded by the USDA Forest Service Pacific Northwest (PNW) Research Station and NASA’s Carbon Monitoring System (CMS), combines forest inventory plots and airborne remote sensing data from NASA Goddard’s Lidar, Hyperspectral, and Thermal Airborne Imager (G-LiHT). The remote forests of interior Alaska have never been included in national inventories of U.S. forest resources based on the costs and complexity of acquiring field data in remote and difficult terrain.
The partnership between NASA and the Forest Service leverages unique capabilities for airborne remote sensing and ground surveys of forest structure and composition. For NASA, key research questions include the spatial distribution of forest carbon stocks, disturbance and recovery from fire, and data fusion—including the opportunity to characterize forest composition using a combination of lidar, hyperspectral, and thermal data from G-LiHT. G-LiHT data collections will also benchmark conditions across the Tanana Valley, an important part of the research domain for NASA’s Arctic and Boreal Vulnerability Experiment (ABoVE). For the Forest Service, the project will test the tradeoffs between a traditional ground-based surveys of forest resources and a hybrid approach to combine a limited ground sample with extensive coverage using G-LiHT airborne lidar and image data. Both NASA and the Forest Service are interested to track changes in forest cover and composition from wildfires and warming climate in coming decades.
As of July 14, the G-LiHT team had completed 40 percent of the planned flight lines across the Tanana region, totaling 3 TB of raw data and more than 2 billion laser shots fired. The flight crew is currently based out of Tok and Fairbanks, Alaska.