  Recent advances with space navigation technologies developed by NASA in
space-based atomic clocks and pulsar X-ray navigation combined with past
successes in autonomous navigation using optical imaging, brings to the
forefront the need to compare space navigation using optical, radiometric, and
pulsar-based measurements using a common set of assumptions and techniques.
This review article examines these navigation data types in two different ways.
First, a simplified deep space orbit determination problem is posed that
captures key features of the dynamics and geometry, and then each data type is
characterized for its ability to solve for the orbit. The data types are
compared and contrasted using a semi-analytical approach with geometric
dilution of precision techniques. The results provide useful parametric
insights into the strengths of each data type. In the second part of the paper,
a high-fidelity, Monte Carlo simulation of a Mars cruise, approach, and entry
navigation problem is studied. The results found complement the semi-analytic
results in the first part, and illustrate specific issues such as each data
type's quantitative impact on solution accuracy and their ability to support
autonomous delivery to a planet.
