The National Ecological Observatory Network (NEON) has begun construction of a new airborne imaging spectrometer that will provide high-resolution remote sensing data over NEON sites and other regions requested by science investigators. The spectrometer, which becomes available in 2015, will measure sunlight reflected from the ground and plant canopies in many narrow spectral bands extending over visible, near- and shortwave-infrared wavelengths. By identifying features in the reflectance spectrum associated with light absorption or scattering within the leaf, for example, it is possible to extract quantitative information about the biochemical properties of vegetation.
The NEON airborne system, when fully operational, will include the imaging spectrometer, a scanning, small footprint waveform-recording LiDAR (Light Detection and Ranging), and a high-resolution digital camera. Together, these instruments will provide spatially explicit information on the canopy biochemistry and structure, land use, and land cover of regional vegetation. Three complete airborne systems are planned for installation into Twin Otter aircraft to cover NEON sites each year. The systems will provide data in response to Principal Investigator requests to support specific research projects and experiments, regional studies, and follow-up after extreme events. Furthermore, the Observatory is planned to operate for 30-plus years, collecting measurements at the scale of organisms for decades over thousands of square miles, a previously unheard of science capability for studying the plant community, physiological, and evolutionary ecology.
Imaging reflectance spectroscopy was originally developed in the 1970s, based on insights derived from laboratory analysis of natural materials. The first airborne demonstration of this technique was with the Airborne Imaging Spectrometer, built by the Jet Propulsion Laboratory (JPL) in 1982. JPL has continued to lead development of state-of-the-art airborne spectrometers over the last decade driven largely by scientific work with the follow-on Airborne Visible and Infrared Imaging Spectrometer (AVIRIS).
Recent improvements in optical design and component fabrication at JPL coupled with new detector array technology have enabled finer image resolution and a higher degree of spectral precision than before. This makes possible meter-scale resolution at the level of individual plant canopies or small groups of organisms from aircraft. JPL is building an airborne spectrometer incorporating these technologies in partnership with NEON as a demonstration of its performance capabilities; this spectrometer will become a key component of the NEON instrumentation.
Science investigators needing NEON airborne data will apply through a process familiar to oceanographers and atmospheric scientists. Principal Investigators will submit a research proposal to the National Science Foundation (NSF) or another sponsoring agency for the resources needed to support their activities. NEON will, in turn, give NSF an assessment of the request in terms of cost, synergy with and potential impacts on other NEON activities, implementation challenges, and other resources required. Based on the review and assessment of the science proposal, the Foundation will decide whether or not to support the requested investigation. A similar but streamlined process will be available to investigators for immediate consideration in response to extreme or unexpected events.
For more information about the National Ecological Observatory Network, visit www.NEONinc.org.