Geolocation of RF Emitters with a Formation-Flying Cluster of Three Microsatellites

In 2017, the HawkEye 360 Pathfinder mission will demonstrate the capability to perform high-precision RF geolocation using a formation-flying cluster of microsatellites. HE360 has developed an innovative combination of classical and novel geolocation algorithms that will enable precise geolocation of RF emitters related to a broad array of business enterprises. These algorithms are robust to errors in self-reported geolocation data such as those commonly seen in maritime radio service systems like the Automatic Identification System (AIS). Each spacecraft in the Pathfinder cluster will host a primary payload consisting of a Software Defined Radio (SDR) capable of covering various RF segments spanning VHF through Ku-Band. The spacecraft will leverage formation-flying techniques and propulsion technology demonstrated on earlier cubesat missions to maintain a loose, long-term, geometrically diverse formation where all three spacecraft have co-visibility of the signal of interest. This paper describes the challenges associated with the demanding requirements of this Pathfinder mission, the technology and architectural approach that enable it, and the value of independent geolocation services to commercial, governmental and humanitarian concerns. Furthermore, a future mission consisting of an expanded constellation of similar clusters will be explored.