  For the simulation of anisoplanatic optical turbulence, split-step
propagation is the gold standard. Within the context of the degradations being
limited to phase distortions, one instead may focus on generating the phase
realizations directly, a method which has been utilized in previous so-called
multi-aperture simulations. Presently, this modality assumes a constant $C_n^2$
profile. This work presents an alternative derivation for Zernike correlations
under anisoplanatic conditions. Multi-aperture simulation may easily
incorporate these correlations into its framework and achieve a significantly
higher degree of accuracy with a minimal increase in time. We additionally use
our developed methodology to explain previously reported discrepancies in an
empirical implementation of split-step with the analytic tilt correlation.
Finally, we outline a major limitation for Zernike-based simulation which still
remains.
