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On the Precision of Artificial Satellite Orbit Determination from Observations from an Orbiting Platform
 

Abstract of a contributed paper given at the 37th meeting of the DDA in Halifax, Nova Scotia

This paper addresses the characterization of the precision of observationally determined orbit parameters when optical observations are taken of an artificial satellite ("target") from another orbiting body ("platform"). Of interest are, among others, optimal platform orbits and optimal observing strategies for a given level of observational astrometric precision and for certain types of target orbits. Classical orbit determination methods are not particularly amenable for gaining analytical insight into the characterization of the determined orbital parameter errors. Here we make an attempt to bypass classical orbit determination and look for an approach that can instead make use of certain approximations to the relative distance and velocity vectors. Furthermore, given the modern possibility for spectroscopic optical instruments in space, we also investigate what may additionally be gained from radial velocity observations.

We start with the distance and velocity vectors of an orbiting target body with respect to an orbiting observation platform. We approximate the relative distance and velocity vectors, allowed by certain assumptions such as small eccentricities, relative inclination angle(s), and ratio of orbit radii. We then analytically propagate the observational errors through the equations and characterize what target orbit parameter errors we are able. It turns out this is more difficult than anticipated at first. We then perform numerical simulations to more completely characterize the behaviors of the determined orbit parameter errors.