Passive RF sensing
Operating silently, they detect and geolocate hostile emitters in real time, allowing air defenders to maintain EMCON, gain valuable decision time, and cue other sensors or weapon systems for precise targeting.
Passive RF technology augments traditional radar systems—which are effective but exposed—by adding persistent, rapidly deployable sensors that deliver full Electronic Support Measures (ESM) capability. Aligned with the ‘mix, mass, modularity’ principles of modern IAMD, these sensors enable defenses that are flexible, scalable, and reconfigurable.
CRFS sensor networks seamlessly integrate into layered defense architectures—from Forward Operating Bases to strategic infrastructure—delivering real-time RF intelligence. The TRL‑9 technology fills a critical gap in an integrated air defense ‘Find, Fix, Track, Target, Engage, Assess (F2T2EA)’ process.
Operate in a contested & congested
EMOE
Function in GNSS-denied environments
Customizable signal detectors
Non-library-based detection
Radar augmentation
Interoperable with C2 software
Proven TRL-9 in real-world deployments
A passive RF sensor network complements radar by acting as an early warning system, detecting hostile airborne targets without alerting the enemy and cuing targeting radar.
Detect the signal of interest, not the platform
Custom built signal detectors search for specific signals (including telemetry, video links, payload data transfer) rather than for specific platforms.
Highly accurate 3D TDoA geolocation
Time Difference of Arrival accurately geolocates the position of RF emitters in three dimensions by analyzing the time difference between each sensor and using advanced algorithms.
Operate in GNSS-denied environments
CRFS has several tools to continue spectrum monitoring and geolocation missions in GNSS-denied environments.
Passive RF sensors allow air defenders to operate under EMCON as they can listen without emitting, increasing survivability and helping to monitor blue force comms.
Through open API architecture, you can use CRFS’ spectrum monitoring and geolocation capabilities in your C2 system.
Talk to an advisor about air defense

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Let’s discuss your air defense requirement, 3D TDoA, operating in GNSS-denied environments, and operating under EMCON.
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