LUAI Challenge 2021 on Learning to Understand Aerial Images. - Gui-Song Xia; Jian Ding 001; Ming Qian; Nan Xue 001; Jiaming Han; Xiang Bai; Michael Ying Yang; Shengyang Li; Serge J. Belongie; Jiebo Luo 001; Mihai Datcu; Marcello Pelillo; et al. (ICCVW, 2021)