  We have performed a detailed pulse phase resolved spectral analysis of the
cyclotron resonant scattering features (CRSF) of the two Be/X-ray pulsars
A0535+26 and XTE J1946+274 and the wind accreting HMXB pulsar 4U 1907+09 using
Suzaku observations. The CRSF parameters vary strongly over the pulse phase and
can be used to map the magnetic field and a possible deviation form the dipole
geometry in these sources. It also reflects the conditions at the accretion
column and the local environment over the changing viewing angles. The pattern
of variation with pulse phase are obtained with more than one continuum
spectral models for each source, all of which give consistent results. Care is
also taken to perform the analysis over a stretch of data having constant
spectral characteristics and luminosity to ensure that the results reflect the
variations due to the changing viewing angle alone. For A0535+26 and XTE
J1946+274 which show energy dependent dips in their pulse profiles, a partial
covering absorber is added in the continuum spectral models to take into
account an additional absorption at those phases by the accretion stream/column
blocking our line of sight.
