Space-Time Synchronized UAVs: Time- and Location-Traceable Multi-Angle Aerial Photography

We propose a method for synchronized multi-angle aerial photography employing multiple unmanned aerial vehicles (UAVs), ensuring both temporal and spatial traceability. Achieving temporal and spatial synchronization among viewpoints is crucial when capturing fast-moving or evolving subjects from various angles. This entails synchronized capturing, recording timestamps, and tracking viewpoint states such as location and attitude. We demonstrate successful control of camera shutters in synchronization and recording of timestamps and positions using wireless two-way interferometry. This method results in a movie composed of synchronized frames captured by the remote cameras on the two UAVs, with a time error between frames within 3.5 microseconds, providing adequate temporal precision for various photographic applications. We apply space-time stamps to all frames of the captured videos with microsecond and centimeter-level accuracy. This precise recording of when and where each frame was captured enhances not only the correlation of frames from each viewpoint but also the accuracy of post-processing tasks such as image-based three-dimensional reconstruction and object recognition. Furthermore, our proposed method proves effective for multi-angle visualization of high-speed phenomena using high-speed cameras, owing to its high-precision time synchronization capability.