Ensco, Inc.

Bradley David Farnsworth

David W A Taylor, Jr

William Todd Faulkner

Edward Joseph Kreinar

Robert Barlow Alwood

Christopher Matthew Foster

Derek John Pyner

Russell Alan Fretenburg

Daniel Thomas Goff

Henry Hon-You Leung

Aspects of the present disclosure describe a system and method for synchronizing time, frequency, and phase among a plurality of devices.

Systems and methods for synchronizing time, frequency, and phase among a plurality of devices

A geolocation system includes an originator device configured to transmit a first wireless signal to a transponder device. The transponder device is configured to transmit a second wireless signal to the originator device. The system includes at least one observer device configured to receive the first wireless signal from the originator device and receive the second wireless signal from the transponder device. The system also includes a first processor configured to calculate a transactional difference range at the at least one observer device based on the first wireless signal received at the observer device and the second wireless signal received at the observer device. A corrected transactional difference range value may be calculated by subtracting a time-of-flight of the first wireless signal from the originator device to the transponder device from the transactional difference range. A method of performing geolocation using a transactional difference range is also disclosed.

Geolocation with radio-frequency ranging

Systems and methods for performing distance and velocity measurements, such as by using carrier signals, are disclosed. A measurement system device may include a first antenna configured to receive a first signal from a transmitting device, the first signal having a carrier frequency, and a second antenna configured to receive the first signal from the transmitting device. The measurement system device may also include a processor configured to determine a first differential distance between the first antenna and the second antenna from the transmitting device and to determine a rate of change of the first differential distance. The processor may also be configured to estimate a geometry of the measurement system device relative to the transmitting device using the rate of change of the first differential distance.

Carrier phase distance and velocity measurements

Systems and methods for performing distance and velocity measurements, such as by using carrier signals, are disclosed. A measurement method may include transmitting a first signal from an originator device to a transponder device and determining a carrier phase of the first signal at the transponder device. The measurement method may also include transmitting a second signal from the transponder device to the originator device and determining a carrier phase of the second signal at the originator device. The measurement method may include estimating a relative distance between the originator device and the transponder device using the carrier phase of the first carrier signal, the carrier phase of the second carrier signal. The method may also include estimating the relative distance using a frequency difference. The method may include using an adjusted relative distance to determine a total distance between the originator device and the transponder device.

Unwrapping and prediction of distance and velocity measurements using carrier signals

Systems and methods for performing distance and velocity measurements, such as by using carrier signals, are disclosed. A measurement method may include transmitting a first signal from an originator device to a transponder device, the first signal having a first carrier frequency; and determining a carrier phase of the first signal at the transponder device. The method may include transmitting a second signal from the transponder device to the originator device, the second signal having a second carrier frequency; and determining a carrier phase of the second signal at the originator device. The method may include estimating a distance between the originator device and the transponder device using the carrier phase of the first carrier signal and the carrier phase of the second carrier signal. The method may include estimating the distance between the originator device and the transponder device using a frequency difference between the first carrier frequency and the second carrier frequency.

Distance and velocity measurements using carrier signals

A system and method for estimating the position of an object, such as a person, animal, or machine. The system includes first and second inertial measurement units, a first and second originator antennas, and a first and second transponder antennas. The system uses data from the inertial measurement units to estimate a position of the object. The system also calculates a range measurement between the first originator antenna and first transponder antenna. The system calculates a first CPD measurement between the second transponder antenna and the first originator antenna, and a second CPD measurement between the second originator antenna and the first transponder antenna. The range measurement and at least one CPD measurement are used to update a Kalman filter for estimating the position of the object. The system determines also updates the Kalman filter when one of the inertial measurement units is in a zero-velocity condition.

System and method for tracking and locating a person, animal, or machine

Methods for estimating a distance between an originator and a transponder, methods for calculating a fine time adjustment in a radio, computer-readable storage media containing instructions to configure a processor to perform such methods, originators used in a system for estimating a distance to a transponder, and transponders used in a system for estimating a distance to an originator. The methods utilize fine time adjustments to achieve sub-clock cycle time resolution. The methods may utilize offset master clocks. The methods may utilize a round-trip full-duplex configuration or a round-trip half-duplex configuration. The method produces accurate estimates of the distance between two radios.

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Alexandria, VA, United States of America

Bradley David Farnsworth