  We present an experimental scheme to perform spectroscopy of the
$^2$S$_{1/2}-^2$P$_{1/2}$ and $^2$D$_{3/2}-^2$P$_{1/2}$ transitions in \Ca. By
rapidly switching lasers between both transitions, we circumvent the
complications of both dark resonances and Doppler heating. We apply this method
to directly observe the micromotion modulated fluorescence spectra of both
transitions and measure the dependence of the micromotion modulation index on
the trap frequency. With a measurement time of 10 minutes, we can detect the
center frequencies of both dipole transitions with a precision on the order of
200 kHz even in the presence of strong micromotion.
