Optical design and characterization of geometric distortion and spatial resolution in lens-enhanced aerial imaging by retro-reflection (LeAIRR)

Lens-enhanced aerial imaging by retro-reflection (LeAIRR) improves aerial image resolution by combining a lens with a retro-reflector. This study establishes an optical-design and image-quality evaluation framework for LeAIRR. The design criterion compares the light-source display pixel pitch, magnified onto the retro-reflector plane, with the effective aperture of a retro-reflector element, while the lens aperture governs the diffraction. Geometric distortion is evaluated for single-, two-, and three-lens configurations; spatial resolution is characterized using contrast transfer function measurements with multiple retro-reflector pitches and lens magnifications. The framework yields low distortion and a Nyquist-frequency contrast exceeding 50%, although the usable high-resolution field narrows toward the periphery.