Hybrid Coverage Path Planning for Nonconvex Urban Areas Using Modified Dubins Curves with Exact Decomposition: A Case Study of Adana City

Post-disaster aerial coverage in urban environments demands efficient path planning that ensures full area surveillance while conforming to the kinematic constraints of fixed-wing aerial vehicles. This paper presents a novel hybrid approach that combines Exact Cellular Decomposition and Modified Dubins Path Planning to optimize coverage over nonconvex, multi-island regions, exemplified by a real-world case study of Adana City, Turkey, following the 2022 earthquake. First, the affected area is decomposed into convex subregions using an exact decomposition algorithm tailored for irregular urban topologies. Then, a Back-and-Forth (Boustrophedon) coverage strategy is applied within each subregion to establish a systematic path. To adapt these paths for fixed-wing aerial vehicles, Dubins curves are employed to smooth transitions between turns. However, standard Dubins paths often deviate from optimal coverage, especially at turning points, leading to coverage loss. To overcome this, we introduce a Virtual Waypoint Strategy that generates extended Dubins paths while minimizing deviation from the nominal trajectory. This method significantly improves area coverage while maintaining maneuverability constraints. Evaluations based on the real map of Adana show that the proposed approach reduces coverage area deviation by up to 1.30 square kilometers, compared to 4.07 square kilometers with traditional Dubins paths, thereby enhancing the effectiveness of rapid damage assessment and reconnaissance missions. This work offers a scalable and practical solution for post-disaster aerial vehicle operations in complex urban landscapes.