Observed I_obs, fitted ε_obsI(T_obs) and modelled spectra I_F for footprints sampled during the FP1 observation CIRS_222DI_DIONE001_PIE (see Figs. 6, 7). The modelled spectra are calculated for amorphous ice with grain size, R = 2 mm, and regolith properties A = 0.63, p = 0.5, and K_E0 = 0 (Γ=0) or K_E0= 0.001 W m⁻¹ K⁻¹ (Γ ~ 15). The effect of the spatial sensitivity of FP1 is included (+SS) or not. The Dione GTM at spatial resolution q = 64 is used. Top: footprint #3 located at latitude and west longitude (−30.89°, 123.84°). Bottom: footprint #5 located at latitude and west longitude (–50.40°, 130.02°).