Nanosatellite Constellation and Ground Station Co-design for Low-Latency Critical Event Detection

Abstract: Advancements in nanosatellite technology lead to more Earth-observation satellites in low-Earth orbit. We explore using nanosatellite constellations to achieve low-latency detection for time-critical events, such as forest fires, oil spills, and floods. The detection latency comprises three parts: capture, compute and transmission. Previous solutions reduce transmission latency, but we find that the bottleneck is capture latency, accounting for more than 90% of end-to-end latency. We present a measurement study on how various satellite and ground station design factors affect latency. We offer design guidance to operators on how to choose satellite orbital configurations and design an algorithm to choose ground station locations. For six use cases, our design guidance reduces end-to-end latency by 5.6 to 8.2 times compared to the existing system.