The NASA AfriSAR campaign: Airborne SAR and lidar measurements of tropical forest structure and biomass in support of current and future space missions

Citation

Fatoyinbo T, Armston J, Simard M, Saatchi S, Denbina M, Lavalle M, Hofton M, Tang H, Marselis S, Pinto N, Hancock S, Hawkins B, Duncanson L, Jeffery K & White LTJ (2021) The NASA AfriSAR campaign: Airborne SAR and lidar measurements of tropical forest structure and biomass in support of current and future space missions. Remote Sensing of Environment, 264, Art. No.: 112533. https://doi.org/10.1016/j.rse.2021.112533

Abstract
In 2015 and 2016, the AfriSAR campaign was carried out as a collaborative effort among international space and National Park agencies (ESA, NASA, ONERA, DLR, ANPN and AGEOS) in support of the upcoming ESA BIOMASS, NASA-ISRO Synthetic Aperture Radar (NISAR) and NASA Global Ecosystem Dynamics Initiative (GEDI) missions. The NASA contribution to the campaign was conducted in 2016 with the NASA LVIS (Land Vegetation and Ice Sensor) Lidar, the NASA L-band UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar). A central motivation for the AfriSAR deployment was the common AGBD estimation requirement for the three future spaceborne missions, the lack of sufficient airborne and ground calibration data covering the full range of ABGD in tropical forest systems, and the intercomparison and fusion of the technologies. During the campaign, over 7000 km2 of waveform Lidar data from LVIS and 30,000 km2 of UAVSAR data were collected over 10 key sites and transects. In addition, field measurements of forest structure and biomass were collected in sixteen 1-hectare sized plots. The campaign produced gridded Lidar canopy structure products, gridded aboveground biomass and associated uncertainties, Lidar based vegetation canopy cover profile products, Polarimetric Interferometric SAR and Tomographic SAR products and field measurements. Our results showcase the types of data products and scientific results expected from the spaceborne Lidar and SAR missions; we also expect that the AfriSAR campaign data will facilitate further analysis and use of waveform lidar and multiple baseline polarimetric SAR datasets for carbon cycle, biodiversity, water resources and more applications by the greater scientific community.

Keywords
AfriSAR; LVIS; UAVSAR; GEDI; NISAR; BIOMASS; Gabon; Central Africa; Airborne Campaigns; Forest Structure; Lidar; SAR; PolInSAR; Tropical Forest

Notes
Additional co-authors: Bryan Blair, Christy Hansen, Yunling Lou, Ralph Dubayah, Scott Hensley, Carlos Silva, John R Poulsen, Nicolas Labrière, Nicolas Barbier, David Kenfack, Memiaghe Herve, Pulchérie Bissiengou, Alfonso Alonso, Ghislain Moussavou, Simon Lewis, Kathleen Hibbard

Journal
Remote Sensing of Environment: Volume 264