Passive RF Monitoring for Uncharacterized On-orbit Signals

"Since the retirement of the Space Shuttle program in 2011, the U.S. government no longer has a dedicated, calibrated on-orbit orbital debris detection sensor" says a Request for Information (RFI) conducted by the U.S. Intelligence Advanced Research Projects Activity (IARPA). The RFI further expressed that "Orbital debris collisions are a significant risk to Earth orbiting spacecraft." Assured Space Access Inc. 's (ASAI) existing commercial solution offers a calibrated on-orbit orbital debris detection sensor; ASAI is currently prototyping the Conformal Patch Array Luneburg Lens( CPALL) antenna system as a passive, bi-static radar for commercial monitoring of space debris in the FREE SPACE system. The technology is dual purpose, capable of supporting satellite communications clients, such as ATLAS Space Operations. The system is designed to be dual-use to support a multi-beam multi-mission configuration for commercial and government satellite command and control as well as mission data downlink operations. The prototype system is designed to transmit and receive signals to/from LEO spacecraft in S, X, and Ka/Ku bands. ASAI’s small satellite debris tracking technology utilizes a globally distributed array of Luneburg lens passive radar devices to detect and track resident space objects in LEO to 1cm in size called FREE SPACE. The ASAI FREE SPACE system utilizes technology licensed from the U.S. Army, see Volume 5 for licensing documentation, a conformal array of patch antennas with a Luneburg lens allows the full sky hemisphere to be observed at once. An array of lenses can detect and range multiple objects from many angles without gaps in scan time, making them ideal for fast-moving targets. A vast reduction in sample counts and transmitter power needed for detection is accomplished with novel algorithms for detecting very small signals. ASAI’s approach to FREE SPACE will leverage its Conformal Patch Array Luneburg Lens (CPALL) technology combined with its unique application of compressed sensing methods to detect and track faint RF signal reflections across a distributed network of CPALL sensors. ASAI has designed the CPALL solution as a dual-purpose technology for both satellite tracking technology and satellite communications.