SITUATIONAL awareness of Earth-orbiting particles, such as active satellites and space
debris, is highly important for all current and future space-faring nations. One topic of recent …

We propose two algorithms to provide a full preliminary orbit of an Earth-orbiting object with
a number of observations lower than the classical methods, such as those by Laplace and …

For optical observations of Earth-orbiting objects, multiple observations must be combined to
determine the orbit of the observed object. Whether two arbitrary tracks are of the same …

This paper proposes three Sun-Synchronous Orbit (SSO) Space-Based Space Surveillance
(SBSS) optical constellations with the intention of building up and maintaining a catalog of …

Admissible region methods for initial orbit determination are generally implemented without
considering the contributions of uncertainty in observations or observer state when …

The first integrals of the Kepler problem are used to compute preliminary orbits starting from
two short observed arcs of a celestial body, which may be obtained either by optical or by …

Given partial observation of a space object, the admissible region is defined as the set of all
physically acceptable orbits that are consistent with the observation. Given additional …

The admissible region is defined as the set of physically acceptable orbits (ie, orbits with
negative energies). Given additional constraints on orbital semi-major axis, eccentricity, etc …

Ground-based optical tracking systems used in space surveillance provide no range
information, and an observed arc is too short compared to the orbital period to provide …

A probabilistic admissible-region analysis is proposed for track initiation using anglesonly
measurements. Given three observations and known sensor statistics, the unscented …