  We analyze the three dimensional anisotropy of the galactic cosmic ray (GCR)
intensities observed independently with a muon detector at Nagoya in Japan and
neutron monitors over four solar activity cycles. We clearly see the phase of
the free-space diurnal anisotropy shifting toward earlier hours around solar
activity minima in A>0 epochs, due to the reduced anisotropy component parallel
to the mean magnetic field. The average parallel component is consistent with a
rigidity independent spectrum, while the perpendicular component increases with
GCR rigidity. We suggest that this harder spectrum of the perpendicular
component is due to contribution from the drift streaming. We find that the
bidirectional latitudinal density gradient is positive in A>0 epoch, while it
is negative in A<0 epoch, in accord with the drift model prediction. The radial
density gradient, on the other hand, varies with ~11-year cycle with maxima
(minima) in solar maximum (minimum) periods, but there is no significant
difference seen between average radial gradients in A>0 and A<0 epochs. The
average parallel mean free path is larger in A<0 than in A>0. We also find,
however, that parallel mean free path (radial gradient) appears to persistently
increase (decreasing) in the last three cycles of weakening solar activity. We
suggest that simple differences between these parameters in A>0 and A<0 epochs
are seriously biased by these long-term trends.
