Inference of the chromospheric magnetic field orientation in the Ca ii 8542 Å line fibrilsA. Asensio Ramos, J. de la Cruz Rodríguez, M. J. Martínez González and H. Socas-NavarroA&A, 599 (2017) A133DOI: https://doi.org/10.1051/0004-6361/201629755