System and method for high-assurance, high-accuracy positioning using ranging of satellites

Abstract

A method to calculate position comprising the steps of creating a positioning system, wherein the positioning system comprises at least one satellite, at least one user, and at least one fixed ground site, and wherein the at least one satellite is coupled to a modulating retroreflector and a laser communications receiver, and wherein the at least one user comprises a space object tracking lidar system and a laser communications receiver, and wherein the at least one fixed ground site comprises a space object tracking lidar system and a laser communications transmitter and is configured to determine range and range rate to the modulating retroreflector; using the range and range rate to update the fixed ground site's estimate of a satellite ephemeris; configuring the at least one fixed ground site to use the laser communications transmitter to uplink the ephemeris to the at least one satellite's laser communications receiver; recording the ephemeris into the at least one satellite and replace ephemeris previously stored in the at least one satellite; allowing the at least one user to illuminate the at least one satellite's modulating retroreflector using the laser transmitter: using the modulating retroreflector to modulate the updated ephemeris data onto a laser beam, and reflect the modulated signal back to the user; allowing the user to receive and demodulate the laser signal using the laser communications receiver, allowing the user to measure the range and range-rate of the at least one satellite using the space object tracking lidar system; allowing the user to estimate its position using the range, range-rate, and ephemeris.

Dependencies are inferred from the claim text.