Five years ago, the threat model for a power substation or an LNG terminal didn't include the overhead vertical dimension. Physical perimeter security, access control, CCTV — those were the disciplines. Today, any critical infrastructure security director who isn't accounting for the drone threat is operating with an incomplete threat model.
The challenge isn't only detection. The legal and operational complexity of responding to an unmanned aircraft system over a civilian facility creates constraints that don't exist in military contexts — and those constraints matter enormously for how you architect a defense.
What the Threat Actually Looks Like
The relevant threat drone population for critical infrastructure is not the nation-state military UAS — the Shahed-136 or the TB2. Those get attention because they're dramatic, but they're not the primary threat vector for most domestic critical infrastructure. The realistic threat is Group 1 and Group 2 UAS: multi-rotor and small fixed-wing aircraft under 55 lbs, available commercially for under $2,000, capable of carrying a 2-5 kg payload.
What makes this threat category difficult is the breadth of intent it can serve. The same airframe can perform reconnaissance (persistent loiter at 100m AGL over a substation, mapping transformer positions and guard patterns), direct physical attack (impact with incendiary or shaped-charge payload), or delivery of signal-disrupting packages (GPS jammer dropped near a facility's timing infrastructure). Threat profiling isn't just about the hardware — it's about which attack modality is being employed, which requires the detection system to classify behavior as well as presence.
The RCS of a commercial multi-rotor in the 250g–3kg class ranges from approximately 0.0005 to 0.01 m². At X-band (9–10 GHz), this is below the clutter floor of many conventional surveillance radars. Detection at ranges beyond 800m requires a purpose-built low-RCS radar with appropriate clutter suppression — not repurposed commercial air traffic surveillance equipment.
Jamming Over Civilian Infrastructure: The Liability Problem
The instinct of many facility security teams encountering the drone threat for the first time is to ask: "Can we jam it?" The answer is legally and operationally complicated.
Under 47 U.S.C. § 333, the deliberate transmission of interference to radio communications — including the drone's control link — is a federal violation unless explicitly authorized. The FAA Reauthorization Act of 2018 (Section 1602) created a narrow carve-out authorizing specific federal departments (DHS, DOJ, DOD, DOE, and their agents) to deploy jamming capabilities for facility protection under defined conditions. Private critical infrastructure operators — power companies, port operators, data center operators — are not included in that carve-out.
The practical consequence is that a private facility deploying RF jamming against a drone, even one that is clearly conducting reconnaissance or an attack, is creating federal criminal exposure for the operator. The drone operator may be committing a crime too, but that's a separate proceeding that doesn't protect the facility from its own FCC violation.
We're not saying RF jamming is never the right tool — we're saying that for private critical infrastructure operators, the authorization pathway to deploy jamming legally is not currently available to them, and the operational and legal liability exposure is real. That constraint is one of the primary reasons kinetic defeat without RF emission is a viable and sometimes preferable option for this customer segment.
The Kinetic Intercept Option for Private Operators
Kinetic defeat of a drone over private airspace creates a different set of legal questions — but ones that in many jurisdictions have clearer pathways for private parties than jamming does.
Property defense doctrines in most U.S. states recognize the right to protect property from trespass or attack. A drone conducting a demonstrably hostile overflight — dropping incendiary material, loitering over high-voltage equipment in a manner consistent with targeting — presents a defensible factual basis for a property defense action. This is distinct from shooting at a drone for privacy annoyance, which has generated unfavorable case law. The legal analysis is fact-intensive and jurisdiction-specific, but the pathway exists in a way that federal jamming authorization does not for private operators.
The kinetic system architecture appropriate for a power substation or port terminal differs from a military application in several important respects. Collateral hazard matters. A kinetic round that misses a small drone target at 400m AGL and continues downrange cannot create acceptable collateral risk. This constrains interceptor design: the effective engagement zone must be above the site perimeter, the interceptor must have a designed flight-limit distance after which it is inert, and the engagement authorization logic must include terrain-masking inputs to prevent engagement geometries where downrange fallout could reach occupied areas.
For a scenario like an electrical substation on the outskirts of an industrial zone — say, a 500kV switching station with a 200m exclusion perimeter — a kinetic intercept system sited at the facility boundary with a maximum engagement altitude of 300m AGL and a designed interceptor inert distance of 1,200m can achieve the defeat mission while keeping collateral hazard within the facility's own property boundary. That's the engagement geometry we model in ARES-1's site planning tooling.
Detection Architecture for Civilian Sites
Effective drone defense at a critical infrastructure site starts with persistent, layered detection — not an alarm system, but a sensor architecture that maintains continuous situational awareness across the defended airspace.
The primary sensor for detection at civilian sites is typically a low-RCS search radar operating in X or Ku band, optimized for slow-moving small targets rather than conventional air traffic. Clutter suppression in the processing chain needs to handle ground clutter from fences, trees, and structures within the radar's close range — most commercial low-altitude surveillance radars are designed for open-area deployment and require significant configuration for a complex industrial site environment.
Radar detection alone carries high false-positive rates for small target classes: birds, large insects, wind-driven debris, and equipment vibration can all generate returns in the target size range. The standard mitigation is cueing an EO/IR camera to the radar track within 2-5 seconds of detection to perform visual or thermal confirmation. The EO sensor provides shape and behavior cues that radar cannot; the IR sensor provides identification in low-visibility and nighttime conditions when EO resolution degrades.
ATAK integration — specifically a licensed civilian TAK server deployment — enables the detection layer to share track data with a common operating picture accessible to facility security personnel, on-site responders, and any coordinating law enforcement. Track handoff to law enforcement via a TAK-compliant interface means the facility's detection data can be used as an evidentiary input in prosecution of the drone operator, which is relevant both for deterrence and for liability protection of the facility operator.
Scenario: Port Terminal Threat
Consider a container port terminal operating 24 hours a day with active crane operations, hazardous cargo stowage, and a fuel depot in the northeast quadrant. The site spans approximately 1.2 km along the waterfront with restricted buffer zones on the landward side. Drone threats of concern include reconnaissance of cargo manifests (targeting high-value or sensitive shipments), navigation-signal disruption near the control tower, and direct payload delivery to the fuel storage area.
Detection at this site requires radar coverage across the waterfront approach — where there is no terrain masking — as well as the landward perimeter. Birds are a significant clutter source in port environments, particularly during migration seasons. The detection chain needs a bird-versus-drone discrimination filter that doesn't simply rely on size (some seabirds are Group 1 UAS size) but on flight behavior: controlled hovering, straight-line approach trajectories at constant altitude, and acceleration profiles that exceed biological flight limits are all discriminating features available to a well-tuned extended Kalman filter tracking the target state vector.
Response architecture for this site would tier: RF characterization first (is there a datalink? what frequency?), soft-kill jamming attempt if the RF signature is jammable and the facility has obtained the necessary federal authorization through a contracted federal partner, kinetic defeat authorization as the fallback for jammer-resistant threats or for post-authorization confirmed attack profiles.
What We're Watching
The regulatory environment for critical infrastructure drone defense is not static. The Counter-UAS Technology Innovation Act, the Safeguarding America's Skies Act, and various NDAA provisions from FY2021 through FY2024 have progressively expanded the authorization base — but primarily for federal agencies, not for private operators.
The next meaningful change for private operators may come through a delegated authority mechanism similar to how private airport operators have been progressively brought into the FAA's LAANC architecture for airspace coordination: not direct jamming authority, but coordination with federal partners who hold that authority and can be activated rapidly when the facility's detection system identifies a credible threat. That kind of tiered public-private response architecture is where the regulatory direction seems to be pointing, and it's what we're designing ARES-1's C2 architecture to accommodate.
Physical defense of the airspace above critical infrastructure is a solvable engineering problem. The harder problem — and the one that determines whether the engineering solution can be deployed — is the legal authority question. Operators who work through that question carefully before a threat event, rather than improvising during one, will be better positioned regardless of which defeat mechanism they ultimately choose.