Invariant Corporation has announced the successful integration of the FireFLY passive acoustic sensor and its artificial intelligence-driven EO/IR architecture with the Surface to Air Kinetic Engagement (STAKE) counter-unmanned aircraft system, establishing a fully passive sensor-to-effector kill chain for detecting and defeating unmanned aerial systems.
FireFLY is a passive acoustic sensor developed jointly by Invariant Corporation and Hyperion Technology Group. The integrated capability combines passive acoustic detection, AI-enabled EO/IR sensing and a kinetic effector to provide a detection-to-defeat capability without transmitting radar or radio-frequency energy.
“Small UAS have created an urgent need for distributed sensing and affordable defeat capabilities that can operate with maneuver forces in contested environments. FireFLY adds passive acoustic coverage where radar and RF are challenged. By integrating that passive acoustic detection directly with a proven kinetic effector, we’ve completed a sensor-to-effector kill chain that detects and defeats unmanned aerial systems without ever emitting a signal. It gets us from detection to defeat faster, with less equipment and a smaller electromagnetic footprint,” said Danny Levis, Invariant President.
Passive Detection and AI-Enabled Tracking
The integrated capability uses acoustic signatures generated by UAS to detect, classify and determine the location and altitude of an approaching aircraft without transmitting radar or radio-frequency energy. Track-quality detection data is passed directly to the kinetic system’s command-and-control architecture, providing operators with an actionable track.
The acoustic detection system automatically cues Invariant’s passive EO/IR sensor towards the area of interest. An onboard AI stack called Drone Vision then searches the live video, locates the UAS within the image, fuses the data and maintains target lock as the aircraft moves through the environment without requiring operator input.
The resulting track data is passed to the kinetic system’s fire control to develop a refined firing solution. This layered approach combines broad-area awareness from passive acoustic sensing with image-based EO/IR AI-enabled identification and tracking.
Detection, classification, sensor cueing, visual target acquisition and precision tracking can take place at the edge without an active sensor transmission, reducing the electromagnetic signature of the force.
Layered Counter-UAS Architecture
Unlike traditional radar-dependent architectures, the Invariant solution can maintain continuous awareness without creating an electromagnetic signature that could reveal the location of friendly forces. The system is designed to complement rather than replace radar, electro-optical/infrared and radio-frequency sensors, allowing commanders to construct layered architectures according to the mission, terrain, threat and available resources.
FireFLY can also operate as a complementary sensor layer within broader counter-UAS architectures. When active systems are constrained by radar masking, low-altitude flights, terrain, clutter or RF-silent control methods, passive acoustic detection can provide an independent alert and cue other sensors or effectors towards the threat.
The integration addresses emerging Department of War priorities, with recent DoW experimentation efforts emphasising combinations of passive and active sensors, portable shooters, AI-enabled command and control, and live data networks.
STAKE is an integrated C-UxS system capable of kinetic defeat of Group 1-4 UAS at range using the Advanced Precision Kill Weapon System. According to the supplied information, it provides a cost-effective defeat mechanism at approximately $30,000 per shot.
FireFLY is an acoustic sensor deployed globally that provides acoustic detection of gunshots, rocket and mortar fire, and aircraft, including unmanned aircraft. Using a Sensor Open Systems Architecture, FireFLY is capable of being integrated into C2 or other integrated systems.
