  The field of exoplanetary science has diversified rapidly over recent years
as the field has progressed from exoplanet detection to exoplanet
characterization. For those planets known to transit, the primary transit and
secondary eclipse observations have a high yield of information regarding
planetary structure and atmospheres. The current restriction of these
information sources to short-period planets may be abated in part through
refinement of orbital parameters. This allows precision targeting of transit
windows and phase variations which constrain the dynamics of the orbit and the
geometric albedo of the atmosphere. Here we describe the expected phase
function variations at optical wavelengths for long-period planets,
particularly those in the high-eccentricity regime and multiple systems in
resonant and non-coplanar orbits. We apply this to the known exoplanets and
discuss detection prospects and how observations of these signatures may be
optimized by refining the orbital parameters.
