  We propose a new method to determine the dipole (and quadrupole) component of
a distribution of cosmic ray arrival directions, which can be applied when
there is partial sky coverage and/or inhomogeneous exposure. In its simplest
version it requires that the exposure only depends on the declination, but it
can be easily extended to the case of a small amplitude modulation in right
ascension. The method essentially combines a $\chi^2$ minimization of the
distribution in declination to obtain the multipolar components along the
North-South axis and a harmonic Rayleigh analysis for the components involving
the right ascension direction.

Astrophysics