Efficient Voxel-Based Updating of Changing Low-Altitude Conditions for Prismatic Airspace Topologies

The safe and scalable integration of drones into complex urban low-altitude airspace relies heavily on precise and real-time environmental modeling. However, the extreme volatility of low-altitude environments, often disrupted by dynamic obstacles and Temporary Flight Restrictions (TFRs), poses a severe challenge to existing digital airspace platforms. To address this bottleneck, this paper proposes a rapid airspace environment updating scheme tailored for varying airspace topologies, specifically focusing on prismatic volumes, with a novel EB (Edge-Begin/Edge-End) topology update algorithm as its core contribution. By evaluating local boundary topologies and deploying a deterministic computational scanline, the EB algorithm transforms complex 3D restricted zones into continuous, gap-free voxel sets for high efficiency. Experiments demonstrate that, compared with baselines, our method reduces processing time by over 99% (11.67 s vs. >35,000 s at province level) and peak memory by over 95% (39.73 MB vs. 838.97 MB), while guaranteeing a 0% missed-voxel rate. It also exhibits excellent scalability from district to province.