The deflection of cosmic rays (CRs) in the interstellar magnetic field results in an almost isotropic flux as observed on Earth. However, anisotropies of different angular scales have been predicted at the level of ∼ 10−4 −10−3. Medium scale anisotropic structures on angular scales of ≤ 60o have been predicted due to relative diffusion of CRs in local turbulent magnetic fields, the contribution of local sources, and several other factors. The GRAPES-3 experiment, consisting of a dense array of scintillator detectors, records over a billion CR events per year in the TeV−PeV energy range; hence it is suitable for probing CR anisotropy due to its high statistics. However, a very careful analysis is required as an exceedingly small magnitude of anisotropy can be overwhelmed by systematics such as detector or atmospheric effects. In this talk, we will discuss the details of the analysis method including the observations of several medium scale anisotropic structures that are consistent with the observations of some major air shower arrays, collecting very high statistics.
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