Integrating Ground Communication for Extended Drone Visual Line of Sight

Unmanned Aerial Vehicles (UAVs) are increasingly permitted to operate within Visual Line of Sight (VLoS) under EU and US regulations. However, Beyond Visual Line of Sight (BVLoS) operations remain restricted, with waivers or certifications required. Extended Visual Line of Sight (EVLoS) offers a transitional solution, involving trained observers to assist pilots when visibility is obstructed. We propose enhancing EVLoS by integrating ground infrastructure, specifically city cameras and wireless communication networks already available on the ground, to replace human observers and enable BVLoS capabilities. Fixed and mobile cameras track drones to ensure regulatory compliance, while real-time data transmission via communication networks provides indirect oversight. The approach increases operational range, reliability, and redundancy through multi-hop connectivity. We introduce the Minimum Latency Problem (MLP), a UAV multi-trajectory optimization problem where UAVs are constantly tracked and monitored through ground antennas and city cameras, mimicking the human observers in EVLoS. Our goal is to minimize communication latency while ensuring that the number of antennas used for coverage is minimum. We prove MLP is NP-hard and propose an algorithm to solve it. Experiments on synthetic data demonstrate the effectiveness of our approach in matching coverage and latency requirements.