Radar for Perimeter Security

Ground-based radar has become one of the fastest-growing segments of the perimeter detection market. Where fence sensors detect intrusions at the boundary, radar provides wide-area surveillance — detecting, tracking, and classifying targets across open ground at ranges from hundreds of metres to several kilometres.

This guide covers the radar technologies used in perimeter security, their operating principles, detection capabilities, and the applications where radar offers advantages over other PIDS modalities.

Why Radar for Perimeters

Traditional PIDS technologies — fence sensors, microwave barriers, infrared beams — detect intrusions at a fixed line. They answer a binary question: did something cross this boundary? Radar answers a richer question: what is moving, where is it, how fast, and in which direction?

This capability enables fundamentally different operational responses. Instead of dispatching a guard to a 200-metre fence zone, the operator can watch a tracked target on a map display and direct response teams to a precise location. Radar can detect threats before they reach the fence, providing early warning time that fence sensors cannot.

Radar also covers areas that are difficult or impossible to protect with line-based sensors: open water approaches, airfields, large industrial yards, and terrain where fencing is impractical.

Radar Technologies in Perimeter Security

FMCW (Frequency-Modulated Continuous Wave)

Most perimeter security radars use FMCW modulation. The radar transmits a continuous signal whose frequency ramps linearly over time. When the signal reflects off a target, the difference between the transmitted and received frequencies encodes the target's range and velocity.

FMCW radar provides simultaneous range and Doppler information, enabling the system to distinguish moving targets from static clutter (buildings, vegetation, terrain). Modern FMCW systems achieve range resolution better than one metre and angular resolution sufficient to track individual people at distances of 500 metres or more.

W-Band (77 GHz)

W-band radars operate at very high frequencies, producing narrow beams from compact antennas. This makes them suitable for pole-mounted deployment with precise angular coverage. The high frequency provides excellent resolution for target classification — distinguishing a person from a vehicle from an animal.

Navtech Radar's AdvanceGuard series operates in the W-band, offering 360-degree scanning with detection ranges up to 500 metres in the compact CTS350 and up to 5 km in the longer-range models announced in 2025.

The trade-off is range: W-band signals attenuate more rapidly in rain and fog than lower-frequency alternatives.

X-Band (9–10 GHz)

X-band radars offer longer detection ranges than W-band at the cost of reduced resolution. They are widely used in military and border surveillance where detection at 5–15 km is required. Targets at these ranges appear as tracks on a map display rather than resolved images.

In perimeter security, X-band systems are typically used for wide-area surveillance of large facilities — energy plants, airports, military bases — where the perimeter extends over many kilometres and early warning at maximum range is the priority.

Micro-Doppler and AI Classification

Current-generation perimeter radars increasingly use micro-Doppler analysis and machine learning to classify targets. A walking person has a distinctive Doppler signature — the torso moves at a steady velocity while the arms and legs produce oscillating Doppler shifts. Vehicles produce a different signature. Animals produce yet another.

By training neural networks on thousands of real-world radar tracks, vendors have achieved classification accuracy high enough to filter nuisance alarms automatically. Navtech claims its AI engine can distinguish people, vehicles, and animals with sufficient accuracy to eliminate the majority of false alarms from wildlife and environmental clutter.

Deployment Patterns

Perimeter Fence Complement

The most common deployment pairs radar with an existing fence and fence sensor system. The radar provides early warning of targets approaching the fence from 200–500 metres out. If the target reaches the fence and triggers a fence sensor alarm, the radar track confirms the alarm and provides location data for camera slew and response dispatch.

This layered approach dramatically reduces false alarms — a target must be tracked by radar AND trigger a fence sensor before an alarm is escalated to the response team.

Open Area Surveillance

For sites without fences — waterfront facilities, airfields, large construction sites, temporary security perimeters — radar provides primary detection. The system defines virtual alarm zones: a geo-fenced area on the map display triggers an alert when a tracked target enters.

The challenge in open area deployment is clutter management. Vegetation, water surfaces, and weather produce radar returns that must be filtered without suppressing real targets. Site-specific commissioning is essential.

Border and Critical Infrastructure

Long-range X-band radars monitor border segments and critical infrastructure perimeters measured in tens of kilometres. These systems track everything that moves in the surveillance volume and present tracks on a tactical display. Operators or automated rules determine which tracks warrant response.

DHS and CBP use ground-based surveillance radar extensively along the US southern border, integrated with camera towers for visual confirmation. The UK Ministry of Defence and European border agencies deploy similar capabilities.

Integration Requirements

Radar provides maximum value when integrated with camera systems and a security management platform. The standard integration model is radar-cued camera: when the radar detects and tracks a target, it sends coordinates to a PTZ camera, which automatically slews to the target and provides visual confirmation.

This requires tight integration between the radar's coordinate system and the camera's positioning system. Most perimeter radar vendors provide native integration with major VMS platforms (Milestone, Genetec) and offer APIs for custom integration.

Map-based display is essential for operational use. Radar tracks displayed as moving dots on an aerial photograph or site map give operators immediate spatial awareness that raw alarm lists cannot provide.

Key Vendors

Navtech Radar — AdvanceGuard series, W-band FMCW, 360-degree scanning, detection to 5 km. UK-based. Strong partnership with SightLogix for radar-camera integration. Announced extended-range 5 km model in 2025.

Axis Communications — AXIS D2210-VE Security Radar, compact 180-degree coverage to 60 metres. Designed for integration with Axis cameras rather than standalone wide-area surveillance. Swedish. Launched bispectral PTZ with integrated radar concepts at GSX 2025.

Blickfeld — LiDAR-based 3D detection with some radar-like capabilities. Now part of Senstar following the 2025 acquisition. German.

Magos Systems — SR series ground surveillance radar, mid-range detection for commercial and government applications. Israeli.

FLIR/Teledyne — Ranger R series ground surveillance radar for military and border applications. Long-range X-band. US-based.

When to Choose Radar

Radar is the right choice when the site requires detection beyond the fence line, when the perimeter is too long for cost-effective fence sensor coverage, when open areas or water approaches need protection, or when operational requirements demand target tracking and classification rather than simple alarm detection.

Radar is not the right choice for indoor applications, for very short perimeters where simpler technologies suffice, or for budgets that cannot accommodate the integration effort required to extract full value from radar data. A radar installed without camera integration and map display delivers only a fraction of its potential capability.