Chromospheric cloud-model inversion techniques

Spectral inversion techniques based on the cloud model are extremely important for the study of properties and dynamics of various chromospheric cloud-like structures. I will review several inversion techniques based on simple (constant source function) and more elaborated cloud models as well as on grids of synthetic line profiles produced for a wide range of physical parameters by different non-LTE codes. I will show several examples of how such techniques can be used, in different chromospheric lines, for the study of structures of the quiet chromosphere such as mottles/spicules, as well as for active region structures such as fibrils, arch filament systems (AFS), filaments and flares.