Mini-EUSO is a detector observing the Earth in the ultraviolet band from the International Space
Station through a nadir-facing window, transparent to the UV radiation, in the Russian Zvezda
module. Mini-EUSO main detector consists in an optical system with two Fresnel lenses and a
focal surface composed of an array of 36 Hamamatsu Multi-Anode Photo-Multiplier tubes, for
a total of 2304 pixels, with single photon counting sensitivity. The telescope also contains two
ancillary cameras, in the near infrared and visible ranges, to complement measurements in these
bandwidths. The instrument has a field of view of 44 degrees, a spatial resolution of about 6.3 km on the
Earth surface and of about 4.7 km on the ionosphere.
The telescope detects UV emissions of cosmic, atmospheric and terrestrial origin on different
time scales, from a few 𝜇s upwards. On the fastest timescale of 2.5 𝜇s, Mini-EUSO is able
to observe atmospheric phenomena as Transient Luminous Events and in particular the ELVES,
which take place when an electromagnetic wave generated by intra-cloud lightning interacts with
the ionosphere, ionizing it and producing apparently superluminal expanding rings of several 100
km and lasting about 100 𝜇s. These highly energetic fast events have been observed to be produced
in conjunction also with Terrestrial Gamma-Ray Flashes and therefore a detailed study of their
characteristics (speed, radius, energy ...) is of crucial importance for the understanding of these
phenomena.
In this paper we present the observational capabilities of ELVE detection by Mini-EUSO and
specifically the reconstruction and study of ELVE characteristics.