  The emission geometries, e.g. the emission region height, the beam shape, and
radius-to-frequency mapping, are important predictions of pulsar radiation
model. The multi-band radio observations carry such valuable information. In
this paper, we study two bright pulsars, (PSRs B0329+54 and B1642-03) and
observe them in high frequency (2.5 GHz, 5 GHz, and 8 GHz). The newly acquired
data together with historical archive provide an atlas of multi-frequency
profiles spanning from 100 MHz to 10 GHz. We study the frequency evolution of
pulse profiles and the radiation regions with the these data. We firstly fit
the pulse profiles with Gaussian functions to determine the phase of each
component, and then calculate the radiation altitudes of different emission
components and the radiation regions. We find that the inverse Compton
scattering (ICS) model can reproduce the radiation geometry of these two
pulsars. But for PSR B0329+54 the radiation can be generated in either annular
gap (AG) or core gap (CG), while the radiation of PSR B1642-03 can only be
generated in the CG. This difference is caused by the inclination angle and the
impact angle of these two pulsars. The relation of beaming angle (the angle
between the radiation direction and the magnetic axis) and the radiation
altitudes versus frequency is also presented by modelling the beam-frequency
evolution in the ICS model. The multi-band pulse profiles of these two pulsars
can be described well by the ICS model combined with the CG and AG.
