Coffee ripeness monitoring using a UAV-mounted low-cost multispectral camera - Rosas, Jorge Tadeu Fim; Pinto, Francisco de Assis de Carvalho; Queiroz, Daniel Marçal de; Villar, Flora Maria de Melo; Valente, Domingos Sárvio Magalhães; Martins, Rodrigo Nogueira (Precision Agriculture, 2021)