Distance Near -field Far-field Reactive Radiating (Fresnel) (Fraunhofer) Antenna Antenna D (m) 1 2 4 8 Reactive NF boundary, RRNF (m) 0.83– 0.94 2.35– 2.67 6.65– 7.55 18.8– 21.4 Fraunhofer distance, RFF (m) 3.60– 4.64 14.4– 18.5 57.5– 74.2 230– 297 * Drone method: repeatable 2D slice field verification (azimuth / elevation), supported by cross-checks and an uncertainty budget. For full far-field characterization of large apertures: use coherent NF sampling & NF -to-FF transformation (amplitude and phase required). Assumed band: f = 539–695 MHz, λ = 0.43 –0.56 m ✓ The drone flight radius may be near-field for large apertures. It is best interpreted as radiating near -field (Fresnel) field verification , unless the Fraunhofer condition is satisfied. Reactive –Radiating boundary Fraunhofer boundary At R = 28.6 m: far -field holds for D ≲ 2.5 –2.8 m (UHF); larger apertures are in the Fresnel region.