Free space optics to enable high data rate download from LEO satellites: The impact of clouds

The complexity and spatial resolution of remote sensing equipment embarked on Earth Observation (EO) satellites and Deep Space (DS) probes is continuously increasing and so is the amount of the data collected by such instruments. As a result, there is an increasing need of bandwidth to download such data during the limited contact time with ground stations. This contribution investigates the feasibility of a 1.55-micron laser link for the direct connection between an EO LEO satellite and a ground station (La Teide observatory in Tenerife, Spain), by specifically addressing the impairments caused by water clouds, whose effects are classified by cloud type and quantified by using synthetically generated three-dimensional cloud fields. Results confirm the extremely detrimental effects of clouds on optical links and, for the specific case considered (minimum elevation angle of 10°), indicate that a 33-dB margin would be required to achieve the Earth-LEO link availability for 90% of the contact time.