NOVEL GRAVITATIONAL MODELLING OF IRREGULAR CELESTIAL BODIES Programme Discovery Programme Reference 2006-56 Contractor Deimos Start Date 2006 End Date 2009 Country Portugal More Like This Collaborative calibration of MEO GNSS signal biases based on LEO satellites GNSS-BICS Weak GNSS Signal Navigation on the Moon Enhanced Surrounding Awareness and Navigation for Autonomous Vessels Absolute Navigation at Sub-cm Level - Phase 2 Using Auctions for PI Activity Negotiations