Experimental Evaluation of Patterned Reflective Surfaces for Solar Glare Reduction in Small UAV Platforms

Résumé

Small unmanned aerial vehicles (UAVs) increasingly require optical signature control in order to reduce visual detectability during daylight operations. This study investigates the influence of mirror-type polymer surface treatments on solar glare behavior and proposes a patterned reflective configuration as a passive mitigation strategy. A small multirotor UAV platform was partially covered (35–40%) with a PET-based reflective film exhibiting high specular reflectance (approximately 80–85%), and its visual response was evaluated under direct solar illumination.
Experimental observations indicated that continuous mirror-like surfaces generate intense specular glints for surface–sun incidence angles between approximately 20° and 45°, with glare visibility durations of 1.5–2.0 seconds. To reduce glare intensity, a segmented surface pattern was introduced, decreasing the estimated effective specular area from 30–35% to 15–20%. The patterned configuration demonstrated a shorter glare duration (0.5–0.8 seconds) and a proportional reduction in glare alignment probability. The results indicate that while reflective polymer coatings may contribute to background blending under diffuse lighting conditions, continuous mirror-like surfaces increase detection risk under direct sunlight.  Patterned segmentation represents a low-cost, geometrybased approach for solar glint mitigation and optical camouflage enhancement in small UAV platforms.