One of the main problems faced by the Space Situational Awareness community is the detection and characterization of faint objects around geosats. Independent of the origin of these objects, whether they are debris or controlled spacecraft, they can potentially harm these assets and contaminate the geobelt environment. The challenge of detecting these companion objects comes from their proximity and brightness ratio relative to geosats. Here we present a novel interferometric fringe nulling technique, aimed at solving these issues. This technique takes advantage of the fact that the presence of companions introduces large phase fluctuations in the fringe phase observed by an interferometer, when the interferometer is observing a target at spatial frequencies where the fringe amplitude is near zero. We describe the ongoing development of this technique at the Navy Precision Optical Interferometer, and the results of simulations of interferometric observations of satellites with companions. We also present the current state of the NPOI and related SSA work being done with this interferometer, as well as undergoing upgrades to the system.
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