Correlation between airborne and ground-based waveform LiDAR at Harvard Forest

Background/Question/Methods

The NEON Airborne Observation Platform (AOP) is designed to support research on a range of important themes in ecology in response to grand challenges in the study of biodiversity, biogeochemistry, climate change, ecohydrology, infectious disease, invasive species, and land use change. This system is now coming online. Each AOP payload consists of a VSWIR imaging spectrometer with a spectral resolution of approximately 5nm, a full waveform LiDAR, and a high-resolution color digital camera, providing spatially-explicit information on regional vegetation canopy biochemistry and structure, plus land cover and land use.  A series of test flights were conducted during the first year of NEON construction with the goal of evaluating sensor functionality and performance, exercise remote sensing collection protocols, and provide data for algorithm and product validation. AOP test flights were conducted at Harvard Forest, Massachusetts in August 2012 with a focus on vegetation chemistry and structure measurements. The remote sensing instruments collected data on four different days flying at different altitudes, different flight patterns, and varying LiDAR instrument configurations. Ground-based observations were collected throughout several different vegetation communities in coordination with the AOP flights including measurements of vegetation structure with ground-based LiDAR.  

Results/Conclusions

One objective of this study was to compare measurements of the vegetation structure observations (such as canopy height) between airborne LiDAR and ground-based LiDAR, particularly as instrument collection parameters, such as aircraft altitude, and spatial sampling were varied and how these affect derived geophysical data products. This information will then be used to inform AOP operational collection strategies and airborne sampling designs. We present the result of our initial analysis of these complementary data sets and potential impacts on data product retrievals resulting from different airborne collection parameters.