Estimation of optimal wavelengths for atmospheric non-line-of-sight optical communication in the UV range of the spectrum in daytime and at night for baseline distances from 50 m to 50 km.

Abstract

For implementation of non-line-of-sight optical communication, the wavelength from the range 200-400 nm at which the signal-to-noise ratio reaches a maximum depending on the baseline distance is estimated. The estimates are performed in the daytime, at moonlit night, and without background radiation. The results obtained allow us to recommend λ=290nm for the implementation of the long-range communication in the daytime and λ=350nm at night. For impulse response that provides the basis for estimating the communication channel quality, four algorithms of the Monte Carlo method are considered. The algorithm with modified double local estimate provides the least error for the same number of photon trajectories. UV radiation is potentially dangerous to humans, and therefore, the illuminance of the Earth's surface is estimated under the optical axis of the source for baseline distances of 2, 10, and 100 m together with the time period of a continuous communication session safe for operators.