TY CONF TI FEATURES OF UAV ROUTE PLANNING IN CONDITIONS OF INSUFFICIENT GLOBAL NAVIGATION SATELLITE SYSTEM SIGNALS KW UAV KW drone KW navigation KW autonomy KW route planning KW GNSS KW GPS KW fault tolerance KW inertial navigation JO MODELING INFORMATION SYSTEMS AND TECHNOLOGIES – 2026 AU Vragov, S.A. AU Frolov, S.V. PY 2026 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov