METHODS FOR PASSIVE OPTICAL DETECTION AND RELATIVE NAVIGATION FOR RENDEZVOUS WITH A NON-COOPERATIVE OBJECT AT MARS

Long-range passive optical detection of an orbiting inert sphere by a robotic Mars orbiter is investigated and trades are described in terms of detectability via reflected visible light in the presence of orbit uncertainty, gravitational perturbations, and camera electronics noise. A new approximate equation for signal-to-noise ratio (SNR) is developed to include most relevant camera imperfections, diffraction, and stray light from the Mars limb as relevant to this scenario. Using this method, a notional camera suite is designed to meet detection, navigation, and redundancy requirements for an example mission scenario. Results from a simulation tool demonstrate the long-range initial detection strategy in the presence of perturbations from various sources. Navigation analysis shows that the information gathered using passive optical detection is sufficient to begin orbit matching. Finally, applicability of this sensor suite is examined relative to later phases.