  Solar contamination, due to moonlight and atmospheric scattering of sunlight,
can cause systematic errors in stellar radial velocity (RV) measurements that
significantly detract from the ~10cm/s sensitivity required for the detection
and characterization of terrestrial exoplanets in or near Habitable Zones of
Sun-like stars. The addition of low-level spectral contamination at variable
effective velocity offsets introduces systematic noise when measuring
velocities using classical mask-based or template-based cross-correlation
techniques. Here we present simulations estimating the range of RV measurement
error induced by uncorrected scattered sunlight contamination. We explore
potential correction techniques, using both simultaneous spectrometer sky
fibers and broadband imaging via coherent fiber imaging bundles, that could
reliably reduce this source of error to below the photon-noise limit of typical
stellar observations. We discuss the limitations of these simulations, the
underlying assumptions, and mitigation mechanisms. We also present and discuss
the components designed and built into the NEID precision RV instrument for the
WIYN 3.5m telescope, to serve as an ongoing resource for the community to
explore and evaluate correction techniques. We emphasize that while "bright
time" has been traditionally adequate for RV science, the goal of 10cm/s
precision on the most interesting exoplanetary systems may necessitate access
to darker skies for these next-generation instruments.
