  We present a comprehensive simulation of the spatial acquisition of optical
links for the LISA mission in the in-field pointing architecture, where a fast
pointing mirror is used to move the field-of-view of the optical transceiver,
which was studied as an alternative scheme to the baselined telescope pointing
architecture. The simulation includes a representative model of the far-field
intensity distribution and the beam detection process using a realistic
detector model, and a model of the expected platform jitter for two alternative
control modes with different associated jitter spectra. For optimally adjusted
detector settings and accounting for the actual far-field beam profile, we
investigate the dependency of acquisition performance on the jitter spectrum
and the track-width of the search spiral, while scan speed and detector
integration time are varied over several orders of magnitude. Results show a
strong dependency of the probability for acquisition failure on the width of
the auto-correlation function of the jitter spectrum, which we compare to
predictions of analytical models. Depending on the choice of scan speed, three
different regimes may be entered which differ in failure probability by several
orders of magnitude. We then use these results to optimize the acquisition
architecture for the given jitter spectra with respect to failure rate and
overall duration, concluding that the full constellation could be acquired on
average in less than one minute. Our method and findings can be applied to any
other space mission using a fine-steering mirror for link acquisition.
