“…A more popular visual approach is feature‐based, with passive techniques utilizing features such as corners in the image (Mammarella et al., ; Vendra et al., ) and active methods using optical markers (Darling, ; Fosbury & Crassidis, ; Lugo, Masselli, & Zell, ; Mahboubi, Kolter, Wang, Bower, & Ng, ; Mati, Pollini, Lunghi, Innocenti, & Campa, ; Wenzel, Masselli, & Zell, ; Williamson et al., ). Indoor multirotor experiments have demonstrated vision‐only feature‐based relative pose estimation for leader‐follower following (Lugo et al., ; Wenzel et al., ), and results in Mahboubi et al. () showed that an air‐to‐air optical marker based localization system could work in an outdoor, airborne environment.…”