Reverse-ephemeris lunar navigation system for long-distance route determination
AssigneeUnited States of America as represented by the Administrator of NASA
InventorsRobert W. Moses, Michael S. Mcbeth
Life of this patent
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Abstract
The disclosed system and method transmit a signal from the surface (or surroundings) of a celestial object to a satellite (for which you know the orbital elements) that re-transmits the signal back to a transceiver on the surface of the celestial object from which a time delay to obtain a range measurement and a Doppler shift to obtain the range-rate can be measured. With knowledge of the satellite's orbital elements and the range and range-rate, a location of the transceiver can be determined.
Claims20
A system configured to determine a location of a transceiver located in close proximity to a surface of a celestial object
- a non-transitory computer-readable medium comprising computer-executable instructions that when executed by a processor, cause the processor to perform at least, including at least:
- receive a beacon signal at a transceiver in operative communication with the processor, the beacon signal being received from at least one satellite orbiting the celestial object, wherein the beacon signal is in a predetermined frequency band;
- transmit an uplink signal to the at least one satellite on an uplink channel;
- transmit by a transponder of the at least one satellite in response to receiving the first signal, a downlink signal on a downlink channel;
- receive the downlink signal at the transceiver and determining a range measurement and a range rate measurement therefrom;
- and
- calculate a location of the transceiver using the range measurement, the range rate measurement, and a known orbital location of the at least one satellite.
A system configured to determine a location of a transceiver located in close proximity to a surface of a celestial body, the system comprising:
- a transceiver configured to transmit and receive signals in a predetermined frequency band;
- a processor;
- a non-transitory computer-readable medium comprising computer-executable instructions that when executed by the processor cause the processor to at least:
- obtain a known orbital location for at least one satellite operating in a frozen elliptical orbit around a celestial body;
- receive one or more signals from a transponder of the one or more satellites;
- determine a range measurement and a range rate measurement based, at least in part, on the one or more signals received from the transponder of the one or more satellites;
- and
- calculate a location of the transceiver using at least the range measurement, the range rate measurement, and the orbital location of the at least one satellite.
A system for determining location of an asset located in close proximity to a surface of a celestial object, the system comprising:
- means for transmitting a beacon signal from at least one satellite orbiting the celestial object;
- means for receiving the beacon signal at a location of the asset and transmitting a first signal to the at least one satellite on an uplink channel;
- means for receiving the first signal and transmitting a second signal on a downlink channel;
- means for receiving the second signal and determining a range measurement and a range rate measurement therefrom, and for calculating a location of the transceiver using the range measurement, the range rate measurement, and a known orbital location of the satellite.
Dependencies are inferred from the claim text.