The distribution, shown in Mollweide projection with the Galactic centre in the middle, of the observed Milky Way fields across the sky. (a) and (b) show fields selected based on Cases 1 and 2, respectively, and observed with GIRAFFE. (c) and (d) show fields selected based on Cases 1 and 2, respectively, and observed with UVES. Green circles – fields with the selection based on VISTA VHS photometry; blue circles – fields with the selection based on 2MASS photometry. Additional fields: blue squares – fields with the selection based on SDSS photometry and 2MASS photometry; and red triangles – fields with the selection based on SkyMapper photometry, VISTA VHS photometry and 2MASS photometry (for more information see Appendix B).