Estimating herbaceous aboveground biomass in Sahelian rangelands using Structure from Motion data collected on the ground and by UAV oleh Simon Taugourdeau, Antoine Diedhiou, Cofélas Fassinou, Marina Bossoukpe, Ousmane Diatta, Ange N’Goran, Alain Auderbert, Ousmane Ndiaye, Abdoul Aziz Diouf, Torbern Tagesson, Rasmus Fensholt, Emile Faye