SWARM CIVIL THREATS
COUNTER-SWARM FOR CRITICAL INFRASTRUCTURE

Threat Scenarios — Civil Drone

Lisa 26's military C-UAS architecture applies to civilian protection with one critical modification: no kinetic L3 response in populated areas. Interceptor drones risk debris falling on civilians. Instead, the civilian version emphasizes detection (find drones fast), jamming (force them to land or return), and law enforcement response (catch the operator). Geofencing — creating virtual no-fly zones enforced by jamming — is the primary tool.

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The Airport Vulnerability

Ten consumer drones costing 500 euros each can close an international airport for hours. The direct cost of 10 drones: 5,000 euros. The cost of airport closure: tens of millions of euros per day in cancelled flights, passenger delays, cargo disruption, and airline compensation. This cost asymmetry makes drone swarm attacks against civilian infrastructure one of the highest-impact, lowest-cost threats available to non-state actors and hostile intelligence services.

The Gatwick Airport incident in December 2018 demonstrated this vulnerability in practice: reported drone sightings (some of which were never confirmed to involve actual drones) closed the airport for 36 hours, affecting approximately 140,000 passengers and costing airlines an estimated 50 million pounds. The UK government had no effective counter-drone capability deployed at the airport. Three years later, the technology gap remains largely unfilled at most European airports including Sweden's four international airports.

Lisa 26 Civil CUAV — Key Differences from Military

The military CUAV system uses kinetic interceptors — one drone rams another at 120 km/h, destroying both. In civilian airspace over populated areas, this creates unacceptable debris risk. Falling drone fragments from 100 meters altitude reach terminal velocity of 30-50 km/h and can injure or kill people on the ground. The civil variant eliminates kinetic interception entirely. Instead, it relies on three non-kinetic layers: detection (RSP-72 radar plus acoustic sensors covering the airport perimeter at 3 km range), directed jamming (FSG-J1 aimed toward the drone — but requiring human authorization because jamming can affect aircraft navigation systems), and law enforcement notification (automatic alert to the regional police drone unit with estimated position and heading).

The human-in-the-loop requirement for jamming in civilian airspace is non-negotiable. An automated jammer that activates against a detected drone could also degrade the ILS (Instrument Landing System) or GPS signals used by approaching aircraft. A trained operator evaluates whether the detected target is actually a hostile drone (not a bird, not a helicopter, not a false alarm) and whether jamming would affect any aircraft on approach before activating the system. This adds 10-15 seconds of delay compared to the military automated system — acceptable because the threat in civilian scenarios is disruption, not destruction.

Cost-Benefit Calculation

The economic case for airport C-UAS is a simple expected-value calculation that any risk manager can reproduce. The system costs €85,000. The question is how many disruption-days per year justify that investment. Gatwick 2018 cost approximately £50 million for 36 hours of closure — that is roughly £33,000 per minute. Even a conservative 1% annual probability of a Gatwick-scale event produces expected annual loss well above the system cost.

# Airport C-UAS cost-benefit analysis
# All figures in EUR. Conservative assumptions.

SYSTEM_COST_EUR = 85_000         # Detection + jammer + integration
SYSTEM_LIFESPAN_YEARS = 10        # Radar + SDR service life
ANNUAL_MAINTENANCE_EUR = 12_000   # Power, calibration, firmware, parts

# Gatwick 2018: 36 h closure, ~£50M total cost (airline + passenger + cargo)
# Source: UK CAA investigation, Dec 2018 - Mar 2019
GATWICK_TOTAL_COST_GBP = 50_000_000
GATWICK_DURATION_H = 36
GBP_TO_EUR = 1.17                 # Approximate 2024-2026 average

gatwick_cost_per_h_eur = (GATWICK_TOTAL_COST_GBP * GBP_TO_EUR) / GATWICK_DURATION_H
# → ~€1,625,000 per hour of closure

# Annualized system cost (amortized + maintenance)
annual_system_cost = SYSTEM_COST_EUR / SYSTEM_LIFESPAN_YEARS + ANNUAL_MAINTENANCE_EUR
# → €20,500 / year

# Break-even: how many hours of prevented closure pay for the system?
break_even_hours = annual_system_cost / gatwick_cost_per_h_eur
# → 0.0126 hours ≈ 45 seconds of prevented disruption per year

print(f"Gatwick-scale cost: €{gatwick_cost_per_h_eur:,.0f}/hour")
print(f"System annualized:  €{annual_system_cost:,.0f}/year")
print(f"Break-even:         {break_even_hours*60:.1f} minutes prevented/year")
# If the system prevents more than ~45 seconds of closure per year
# on average, it has already paid for itself.

Radar Coverage Geometry

The 3 km detection radius at the airport perimeter is not arbitrary — it falls out of the radar horizon and the drone closure-time budget. A consumer drone at 25 m/s (90 km/h) needs 120 seconds to cover 3 km. That is enough time for a human operator to evaluate the track, request authorization, and enable directed jamming. A shorter detection range would collapse this reaction window below human decision latency.

# Detection range vs reaction time budget
import math

TARGET_SPEED_MS = 25              # Consumer drone cruise (DJI M30, etc.)
DETECTION_RANGE_M = 3000          # RSP-72 quoted range, clear-air
RADAR_HEIGHT_M = 12               # Typical airport mast

# Human decision loop (observe → classify → authorize → act)
OBSERVE_S = 5                     # Initial track quality check
CLASSIFY_S = 15                   # Vehicle vs bird, call up PTZ camera
AUTHORIZE_S = 30                  # Supervisor/tower authorization
ACT_S = 10                        # Jammer warm-up + beam slew
REACTION_BUDGET_S = OBSERVE_S + CLASSIFY_S + AUTHORIZE_S + ACT_S  # 60s

closure_time_s = DETECTION_RANGE_M / TARGET_SPEED_MS  # 120 s at 25 m/s
safety_margin_s = closure_time_s - REACTION_BUDGET_S
# → 60 seconds margin

# Radar horizon (4/3 Earth refraction-adjusted)
# d_horizon_km = 4.12 * (sqrt(h_tx) + sqrt(h_target)), h in meters
def radar_horizon_km(h_tx_m, h_tgt_m):
    return 4.12 * (math.sqrt(h_tx_m) + math.sqrt(h_tgt_m))

# Drone at 50 m AGL visible from 12 m mast:
horizon = radar_horizon_km(RADAR_HEIGHT_M, 50)
# → ~43.4 km line-of-sight — detection range is NOT horizon-limited,
# it is sensitivity-limited (RCS of 0.01 m² at 3 km for X-band).

print(f"Closure time at {TARGET_SPEED_MS} m/s over {DETECTION_RANGE_M/1000} km: {closure_time_s:.0f} s")
print(f"Required reaction budget: {REACTION_BUDGET_S} s")
print(f"Safety margin: {safety_margin_s:.0f} s ({safety_margin_s/60:.1f} min)")
print(f"Radar horizon at 12m mast vs 50m drone: {horizon:.1f} km")

Implementation

# Civil CUAV — Airport Protection Configuration
# Lisa 26 adapted for critical infrastructure (no kinetic interceptors)

CIVIL_CUAV_CONFIG = {
    "detection": {
        "sensors": ["RSP-72 radar", "acoustic array", "PTZ camera"],
        "coverage_km2": 25,  # International airport perimeter
        "detection_range_m": 3000,
        "false_alarm_rate": "< 1 per hour"
    },
    "response_levels": {
        "L1_detect": {
            "action": "Alert security operations center",
            "automated": True,
            "latency_s": 2
        },
        "L2_track_identify": {
            "action": "PTZ camera slews to target, AI classifies",
            "automated": True,
            "latency_s": 5
        },
        "L3_jam": {
            "action": "Directional jammer activates toward drone",
            "automated": False,  # Human approval required in civilian airspace
            "reason": "Risk of jamming legitimate aircraft navigation",
            "latency_s": 15  # Includes human approval time
        }
    },
    "key_difference_from_military": {
        "no_kinetic_interceptor": "Population density — falling debris risk",
        "no_autonomous_jamming": "Civilian aircraft use same frequencies",
        "police_notification": "Automated alert to Polisen drone unit",
        "legal_framework": "Requires Transportstyrelsen authorization"
    },
    "cost_per_airport_eur": 85000,  # Detection + jamming + integration
}

import json
print(json.dumps(CIVIL_CUAV_CONFIG, indent=2))

Airport Protection Model

Lisa 26 CUAV architecture adapts to civilian critical infrastructure with one fundamental change: no kinetic interceptors in populated areas. The civilian model uses detection plus jamming plus police notification. RSP-72 radar plus acoustic arrays cover the airport perimeter at 3 km range.

Cost-benefit analysis strongly favors deployment: one prevented airport closure saves more than ten times the system cost. Sweden has four international airports and dozens of military airfields — each represents a potential drone swarm target.

Related Chapters

Sources

Parameter sources. RSP-72 radar specifications — SRC Inc. manufacturer public data. Silvus FSG-J1 jammer characteristics — Silvus Technologies public documentation. PTS (Post- och telestyrelsen) jamming authorisation requirements — Swedish radio regulation SFS 2003:389. Swedish critical-infrastructure protection law: Lag (2010:1011) and related MSB ordinances.

Operational estimates — not validated by FSG-A in the field. €85,000 airport-system cost is an estimate based on BOM of commercially available components (radar + acoustic sensors + Lisa 26 licence + integration work), not an actual contract price. "10× ROI on prevented closure" is an economic estimate, not validated by real deployment. 3 km detection range is the radar manufacturer specification for typical conditions, not verified by FSG-A. FSG-A has not deployed any civilian CUAV system.

Normative sources and standards. MSB (Myndigheten för samhällsskydd och beredskap) published guidance documents on critical-infrastructure protection (publikationer.msb.se catalogue, search by document number). Swedish PTS radio regulation. Gatwick Airport incident reports, December 2018 (Sussex Police public report; UK Civil Aviation Authority investigation). NATO AJP-3.3.2 for short-range air defence. ICAO Doc 10019 "Manual on Remotely Piloted Aircraft Systems" (2015). FSG-A has no civilian CUAV deployment experience — all figures are planning estimates.