PRACTICAL C‑UAS: FROM RF DETECTION TO MULTIBAND JAMMING

With recent incidents at critical sites, like airports and naval bases, small uncrewed aerial systems (sUAS) have become a growing operational concern. Modern opponents utilize drones for surveillance, target spotting, harassment or even weaponized attacks. These drones fly at low altitudes to avoid detection or at high altitudes to bypass counter measures. Advanced missions require special control transmissions, like FHSS (Frequency‑Hopping Spread Spectrum) signals or highly encrypted links. Malicious actors operate non‑cooperative, hard-to-detect drones. These factors make counter‑UAS (C‑UAS) a system‑level challenge: reliable early detection, fast classification, precise geolocation, clear decision support and proportionate countermeasures are all required - and must operate within spectrum management and rules of engagement (ROE) limits.

Core C‑UAS principles

The capabilities required of an operational system are straightforward.

RF‑first detection: control links, telemetry and video downlinks are a clear sign that a drone is present, and passive RF monitoring finds those signals without exposing sensors. Accurate geolocation of both drone and ground controller enables attribution and follow‑on measures. Fast, confidence‑ranked fusion turns multiple sensor inputs into a single prioritized track picture, reducing false alarms and speeding decisions. Proportionate electromagnetic countermeasures - targeted advanced high power multiband jamming and GNSS jamming/spoofing - must be configurable in waveform, power and timing to neutralize threats while limiting collateral impact. Finally, open, modular systems plus tailored training and lifecycle support keep capabilities current and interoperable with partners.

How passive RF direction finding preserves sensor stealth

Passive RF direction finding detects angles of arrival for control and telemetry signals without emitting, preserving sensor stealth. When DF data are fused with automated signal classification and other inputs, the system correlates data to confirm real threats. This confirmed detection can be optically verified by an automatic scoring or by manual verification that gives operators clear, action‑grade information to enable counter measures.

C‑UAS: mission profiles and requirements

C‑UAS deployments fall into three complementary profiles, each with distinct demands. Mobile systems protect convoys and vehicles on the move or when stopped; they must be compact, providing 360° coverage, reduced weight, high-power, need to be easy to install and operate, and provide local geolocation with immediate sensor tasking. Deployed perimeter solutions for forward posts and temporary sites require rapid setup, extended detection range, automatic alerts and seamless integration into the common operating picture. Fixed installations at airfields, ports or critical infrastructure need persistent 24/7 monitoring, wide‑area multiband coverage, scalable effectors and robust evidence recording while coexisting with civilian spectrum users and complying with rules of engagement.

What practical systems look like

A fielded C‑UAS stacks clear technical functions. Wideband, sensitive RF receivers detect weak or intermittent signals. Direction finding and geolocation pinpoint drone and pilot. Low‑latency fusion engines produce a confidence‑ranked picture. Scalable electromagnetic effectors enable targeted disruption. Operator displays should show simple recommended actions and preserve audit logs for attribution and review. Regular training and experienced operators are essential to keep systems mission‑ready and future-proof.

Fielded capability: ARDRONIS by Rohde & Schwarz

Rohde & Schwarz implements these principles in ARDRONIS, a modular, field‑proven C‑UAS family built for the full range of defense use cases - from mobile convoy and vehicle protection, through deployed perimeter defense, to fixed‑site and shipboard installations - with configurable hardware and software for straightforward integration. The suite centers on passive RF precision, automated signal classification, pilot geolocation and scalable multiband disruption, with modular integration and engineered to military environmental and EMC standards.

ARDRONIS covers three areas:

Detect & locate - lightweight RF detection, automatic classification and rapid geolocation (FHSS, optional Wi‑Fi/RemoteID) with pan‑tilt verification.
Effect - control‑link analysis and optimized jamming across 125 MHz - 6 GHz (up to 350 W) with simultaneous multiband capability and selectable modes.
Control center - fuses inputs into confidence‑ranked tracks, guides operators and coordinates effector responses.

ARDRONIS is SAPIENT‑compliant, NATO‑demonstrated, GUARDION‑integrable and field‑proven. Deployed as a system of systems, it speeds detection‑to‑action, reduces false alarms, enables attribution and supports proportionate responses that keep operations running and limit civilian impact.

For guidance on maximizing drone‑defense efficiency and to see how Rohde & Schwarz solutions can support your mission, visit our counter-drone solutions page, contact our experts, or meet us at Milipol Paris 2025.