Interplanetary medium diagnostic during the large event in March 1991 based on GRANAT records

Results of the charged particle measurements on board the GRANAT satellite during the large event in March 1991 are discussed. Explanations of some features of the data behaviour are presented as well as the model assumptions concerning the magnetic field structure near the Sun and in interplanetary space. Large-scale effects, not-related to the shocks, are the focus.