The [CLC][ITAL]u[/ITAL][/CLC][arcmin]′[CLC][ITAL]g[/ITAL][/CLC][arcmin]′[CLC][ITAL]r[/ITAL][/CLC][arcmin]′[CLC][ITAL]i[/ITAL][/CLC][arcmin]′[CLC][ITAL]z[/ITAL][/CLC][arcmin]′ Standard-Star System