Counter-Drone Measures and Civilian Harm in Kenyan Urban Airspace

An open-data quantitative study of the civilian cost of counter-drone (counter-UAS) responses over Nairobi. It models how radio-frequency jamming and kinetic interceptors spill far beyond their intended target — degrading satellite navigation, cellular timing and aircraft approach corridors across the city — and tests whether Kenyan law requires that cost to be quantified before an engagement is authorised.

Abstract

Small uncrewed aircraft operated by non-state actors represent a hybrid security challenge for Kenya: a threat that is militarily framed but whose countermeasures act principally upon civilian systems. This study examines the civilian cost of counter-drone response over Nairobi, establishing whether that cost is computable and whether Kenyan law requires it to be computed. The methodology combines a log-distance radio propagation model with closed-form denial probabilities, fourth-order Runge-Kutta ballistic integration calibrated against published ranges, and a measured 30-metre population surface, applied to ten engagement scenarios across a 30-kilometre analysis area. Findings indicate that a single 50-watt emission denies street-level satellite navigation across a 7.0-km radius, base-station timing across 27.7 km, and aircraft navigation on approach across 94.5 km, affecting 87 to 93.5 per cent of every instrument approach corridor serving the city; projectiles that miss descend up to 7.8 km from the firing point. The study finds Regulation 67 of the Civil Aviation (Unmanned Aircraft Systems) Regulations 2025 confers interception powers without any stated limit referable to persons beneath the engagement, and recommends pre-engagement exposure assessment, technical specification limits, aviation deconfliction, spectrum reconciliation and compensation.

Keywords

counter-unmanned aircraft systems; critical infrastructure interdependency; hybrid threats; proportionality; satellite navigation interference; urban airspace

Status

Submitted to The National Security Journal, Centre for Security and Strategic Studies, National Defence University-Kenya (2026). Currently under review.