Standoff Boundary in Ultraviolet Non-Line-of-Sight Covert Communication

Ultraviolet (UV) communication is widely known for its local confidentiality due to rapid signal attenuation over distance. However, the inherent low background interference in UV communication environments can make signal transmission more easily detectable by an eavesdropper. In this study, we introduce covert communication metrics based on overall photon counting and peak power to assess analytically the covert performance of UV non-line-of-sight (NLOS) communications on photon counting channels. By integrating the covert metrics with the UV omni-directional NLOS channel model, we demonstrate standoff boundaries for the first time. Our simulation results confirm the effectiveness of UV NLOS covert communication and offer vital insights into the design and operational strategies of UV NLOS covert communication systems.