  Context: In this paper we present a validation scheme to investigate the
quality of coronal magnetic field models, which is based upon comparisons with
observational data from multiple sources. Aims: Many of these coronal models
may use a range of initial parameters that produce a large number of physically
reasonable field configurations. However, that does not mean that these results
are reliable and comply with the observations. With an appropriate validation
scheme the quality of a coronal model can be assessed. Methods: The validation
scheme is developed on the example of the EUropean Heliospheric FORecasting
Information Asset (EUHFORIA) coronal model. For observational comparison we use
EUV and white-light data to detect coronal features on the surface (open
magnetic field areas) and off-limb (streamer and loop) structures from multiple
perspectives (Earth view and the Solar Terrestrial Relations Observatory -
STEREO). The validation scheme can be applied to any coronal model that
produces magnetic field line topology. Results: We show its applicability by
using that validation scheme on a large set of model configurations, which can
be efficiently reduced to an ideal set of parameters that matches best with
observational data. Conclusions: We conclude that by using a combined empirical
visual classification with a mathematical scheme of topology metrics a very
efficient and rather objective quality assessment for coronal models can be
performed.
