Implementation of a GNU Radio-Based Search and Rescue Receiver on ESA's OPS-SAT Space Lab

OPS-SAT is the first publicly accessible Hardware/Software Innovation Lab in low Earth orbit. It was launched by the European Space Agency on December 18, 2019, and is open to European academia and industry, allowing new concepts to be tested in space with a range of interesting payloads. This article discusses the implementation and results of an in-orbit demonstration (IOD) using the software-defined radio payload of OPS-SAT together with onboard RF processing techniques. We demonstrate the design of a software configurable search and rescue receiver using GNU Radio, running on Linux in a 3U CubeSat. The system runs on the Satellite Experimental Processing Platform (SEPP) Cyclone V ARM system-on-chip and is able to autonomously detect and decode transmissions from terrestrial 406-MHz beacons from the global COSPAS-SARSAT search and rescue system. Decoded beacon information is logged onboard together with metadata and is downloaded to mission control at ESA/ESOC. The successful IOD paves the way for in-orbit RF experimentation and bridges the gap between satellite operations and the Internet of Things era.