SkyRanger is a reconnaissance drone swarm that maps disaster sites with zero satellite signal. Each aircraft fuses 360-degree LiDAR and IMU data at millisecond scale to build its own 3D map and track its own pose, then synchronizes maps and positions peer-to-peer with no central GPS and no central controller. Wildfires, earthquakes, tunnels and collapsed structures are the places people should not enter, and they are also the places where GNSS stops working. Coordinated swarm coverage targets over 65% higher coverage efficiency than a single drone, over 45% lifecycle savings, and replaces up to five conventional units. One operator carries the swarm to the site and deploys it within minutes. SkyRanger is at prototype stage, with the cooperative navigation system in development.