  Although at least one quarter of early-type barred galaxies host secondary
stellar bars embedded in their large-scale primary counterparts, the dynamics
of such double barred galaxies are still not well understood. Recently we
reported success at simulating such systems in a repeatable way in
collisionless systems. In order to further our understanding of double-barred
galaxies, here we characterize the density and kinematics of the N-body
simulations of these galaxies. This will facilitate comparison with
observations and lead to a better understanding of the observed double-barred
galaxies. We find the shape and size of our simulated secondary bars are quite
reasonable compared to the observed ones. We demonstrate that an authentic
decoupled secondary bar may produce only a weak twist of the kinematic minor
axis in the stellar velocity field, due to the relatively large random motion
of stars in the central region. We also find that the edge-on nuclear bars are
probably not related to boxy peanut-shaped bulges which are most likely to be
edge-on primary large-scale bars. Finally we demonstrate that the non-rigid
rotation of the secondary bar causes its pattern speed not to be derived with
great accuracy using the Tremaine-Weinberg method. We also compare with
observations of NGC 2950, a prototypical double-barred early-type galaxy, which
suggest that the nuclear bar may be rotating in the opposite sense as the
primary.
