  Ariel has been selected as the next ESA M4 science mission and it is expected
to be launched in 2028. During its 4-year mission, Ariel will observe the
atmospheres of a large and diversified population of transiting exoplanets. A
key factor for the achievement of the scientific goal of Ariel is the selection
strategy for the definition of the input target list. A meaningful choice of
the targets requires an accurate knowledge of the planet hosting star
properties and this is necessary to be obtained well before the launch. In this
work, we present the results of a bench-marking analysis between three
different spectroscopic techniques used to determine stellar parameters for a
selected number of targets belonging to the Ariel reference sample. We aim to
consolidate a method that will be used to homogeneously determine the stellar
parameters of the complete Ariel reference sample. Homogeneous, accurate and
precise derivation of stellar parameters is crucial for characterizing
exoplanet-host stars and in turn is a key factor for the accuracy of the planet
properties.
