AVUELO – Imaging Spectroscopy Flight Campaign to Advance Tropical Ecology

Global assessments of vegetation patterns require methods that overcome spatial and temporal limitations of ground measurements. Remote sensing enables the systematic observation of vegetation properties across biomes on a global scale, providing benchmarks and/or novel resolution for characterizing the biosphere and its biodiversity. Among earth orbiting sensors, imaging spectrometers provide continuously resolved information about chemical, structural and physiological plant traits that affect ecosystem function and are indicative of plant phylogenetic diversity. As international efforts lead towards repeated wall to wall coverage of spectral properties of the Earth’s surface, there is a growing need for coordinated calibration and validation of models that predict functional plant traits from spectral information across different biomes. Here, we present the AVUELO campaign (Airborne Validation Unified Experiment Land to Ocean), which is focused on the calibration and validation of trait models in tropical ecosystems to improve the monitoring and understanding of ecosystem function and biodiversity.

AVUELO is a NASA campaign that was conducted in February 2025 in Panama and Costa Rica in collaboration with the Smithsonian Tropical Research Institute (STRI). During the campaign, the airborne imaging spectrometer AVIRIS-3 acquired data over tropical terrestrial and marine ecosystems at 1 and 3 m spatial resolution. These airborne acquisitions were complemented by ground sampling.  The ground samples from taxonomically identified trees were chosen to represent as much of the phylogenetic variation found in Panama as possible and included more than 1,000 top-of-canopy leaf samples from over 400 tropical forest species for measurements of leaf spectral and chemical properties. The relationships between measured spectra and vegetation properties will be used to improve models that predict plant traits from reflectance spectra acquired by currently operational (EMIT, PRISMA, DESIS, HISUI, EnMAP) and upcoming (NASA-EAGLE-VSWIR and ESA-CHIME) spaceborne imaging spectrometers. This effort will enhance the capability to monitor ecosystem function and biodiversity consistently across biomes at a global scale.