Prominence diagnostic based on the MSDP observation. (a) Hα intensity at the line centre, (b) Doppler velocity, and (c) FWHM. The contours present the Hα prominence defined as Mask-Hα (see Sect. 4.7). The blue vertical lines in panel a are the two selected slit positions (A, B) used to analyse the profiles (Figs. A.3 and A.5) and for plasma parameter diagnostics (Table 3). The small horizontal lines are the positions corresponding to profiles A1–A15 and B1–B11.