Analysis of unresolved photospheric magnetic field structure using Fe I 6301 and 6302 lines M. Gordovskyy, S. Shelyag, P. K. Browning and V. G. Lozitsky A&A, 619 (2018) A164 Published online: 20 November 2018 DOI: 10.1051/0004-6361/201833421