Observation of heliospheric disturbances in muon component of cosmic rays at ground level

Results of monitoring of heliospheric disturbances by means of ground-based muon hodoscope are presented. The approach is based on the fact that the disturbed regions in solar wind and in IMF modulate galactic cosmic rays and lead to changes of ground level muon intensity in given direction. To study such modulations the muon hodoscope URAGAN (MEPhI, Moscow) allowing to measure the muon flux variations from thousands of directions of the celestial hemisphere with a high statistics is used. Methods of projection of muon arrival directions to GSE coordinate system (taking into account geomagnetic field) which give a possibility to observe heliospheric perturbations at large distances from the Earth are described. The examples of observations of heliospheric disturbances in 'muon window' are presented. Perspectives of the further use of muon hodoscopes are also discussed (authors)