Session
Year in Review
Location
Salt Palace Convention Center, Salt Lake City, UT
Abstract
Gray Jay Pathfinder (GJP) is an experimental microsatellite constellation that has been designed, built, and operated by the Space Flight Laboratory (SFL), for Defence Research and Development Canada (DRDC). GJP launched in January 2025, and consists of three microsatellites, developed using SFL’s 30kg DEFIANT platform, flying in formation in a sun-synchronous orbit at a 510km altitude. All three spacecraft carry radio frequency (RF) payloads capable of receiving raw spectrum in the VHF, UHF, L, S, and X radar bands. The RF payloads include a combination of in-house designed and COTS antennas, in-house designed antenna front ends, a payload computer with an in-house designed daughter card enabling SDR functionality, and dedicated COTS AIS and ADS-B receivers. One spacecraft acts as the reference spacecraft for the formation and carries a thermal infrared instrument operating in the 8-14 μm range with a 65 meter ground sampling distance. The other two spacecraft carry propulsion systems and maintain the desired formation.
Gray Jay Pathfinder was designed to demonstrate maritime and airborne vessel monitoring techniques on low-cost microsatellite platforms, which can then be applied to a future Arctic surveillance constellation. These techniques are, (1) emitting target detection and geolocation, including AIS and ADS-B signals as well as arbitrary pulsed signals, (2) target filtering, identifying possible “non-cooperative” vessels whose geolocated emissions do not match their reported position, and (3) “tip and cue,” commanding the IR instrument to capture thermal imagery of potential non-cooperative vessels. None of the described data processing and decision-making steps require a human operator in the loop, and the GJP mission involved extensive development of payload data processing software, as well as a new payload planning system that enables spacecraft operators to command payload observations.
In this paper, we will describe the Gray Jay Pathfinder mission concept and spacecraft systems, and share results from its first year on orbit, during which GJP successfully demonstrated RF detection and geolocation of AIS signals, ADS-B signals, and arbitrary pulsed signals, as well as demonstrating tip and cue IR imaging of geolocated signals.
Document Type
Event
Gray Jay Pathfinder: One Year of Maritime and Airborne Vessel Monitoring With a Formation-Flying Constellation of Microsatellites
Salt Palace Convention Center, Salt Lake City, UT
Gray Jay Pathfinder (GJP) is an experimental microsatellite constellation that has been designed, built, and operated by the Space Flight Laboratory (SFL), for Defence Research and Development Canada (DRDC). GJP launched in January 2025, and consists of three microsatellites, developed using SFL’s 30kg DEFIANT platform, flying in formation in a sun-synchronous orbit at a 510km altitude. All three spacecraft carry radio frequency (RF) payloads capable of receiving raw spectrum in the VHF, UHF, L, S, and X radar bands. The RF payloads include a combination of in-house designed and COTS antennas, in-house designed antenna front ends, a payload computer with an in-house designed daughter card enabling SDR functionality, and dedicated COTS AIS and ADS-B receivers. One spacecraft acts as the reference spacecraft for the formation and carries a thermal infrared instrument operating in the 8-14 μm range with a 65 meter ground sampling distance. The other two spacecraft carry propulsion systems and maintain the desired formation.
Gray Jay Pathfinder was designed to demonstrate maritime and airborne vessel monitoring techniques on low-cost microsatellite platforms, which can then be applied to a future Arctic surveillance constellation. These techniques are, (1) emitting target detection and geolocation, including AIS and ADS-B signals as well as arbitrary pulsed signals, (2) target filtering, identifying possible “non-cooperative” vessels whose geolocated emissions do not match their reported position, and (3) “tip and cue,” commanding the IR instrument to capture thermal imagery of potential non-cooperative vessels. None of the described data processing and decision-making steps require a human operator in the loop, and the GJP mission involved extensive development of payload data processing software, as well as a new payload planning system that enables spacecraft operators to command payload observations.
In this paper, we will describe the Gray Jay Pathfinder mission concept and spacecraft systems, and share results from its first year on orbit, during which GJP successfully demonstrated RF detection and geolocation of AIS signals, ADS-B signals, and arbitrary pulsed signals, as well as demonstrating tip and cue IR imaging of geolocated signals.
