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

Abstract: Disclosed herein are methods, devices, and systems for determining geographic location and time. In one embodiment, a radio and a processor configured for deriving a first signal tone originating from a first remote antenna located at a first location; deriving a second signal tone originating from a second remote antenna located at a second location; deriving a third signal tone originating from a third remote antenna located at a third location; determining a first frequency and a first phase at a first time of the first signal tone; determining a second frequency and a second phase at a second time of the second signal tone; and determining a third frequency and a third phase at a third time of the third signal tone. The method further includes determining a geographic location based on the first, second, and third frequencies; the first, second, and third phases; and the first, second, and third locations.

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

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

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

Abstract: The subject matter described herein includes methods and systems for performing physical measurements using radio frequency (RF) signals. According to one embodiment of the present invention, a method is disclosed for determining the distance between a first radio device and a second radio device. The method includes transmitting a radio frequency (RF) signal from the first radio device and receiving the RF signal by the second radio device. The method further includes a determining a carrier frequency of the RF signal and determining a slope of a carrier phase versus the carrier frequency corresponding to a rate of change of the carrier phase with the carrier frequency. The method also includes determining a physical distance between the first radio device and the second radio device based on the slope; wherein the physical distance is proportional to the slope plus an integer ambiguity term and a bias term.

Abstract: The subject matter described herein includes methods and systems for performing physical measurements using radio frequency (RF) signals. According to one embodiment of the present invention, a method is disclosed for determining the distance between a first radio device and a second radio device. The method includes transmitting a radio frequency (RF) signal from the first radio device and receiving the RF signal by the second radio device. The method further includes a determining a carrier frequency of the RF signal and determining a slope of a carrier phase versus the carrier frequency corresponding to a rate of change of the carrier phase with the carrier frequency. The method also includes determining a physical distance between the first radio device and the second radio device based on the slope; wherein the physical distance is proportional to the slope plus an integer ambiguity term and a bias term.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A locating system, includes at least one initiator configured to operate at a first clock frequency, and to transmit a measurement signal including a first preamble; and at least one transponder configured to operate at a second clock frequency, to receive the measurement signal, and to transmit a response signal to the initiator, the response signal including a second preamble. The initiator is further configured to calculate, based on the response signal, a distance between the initiator and the transponder for determining a location of the transponder.

Abstract: 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.

Abstract: A method for processing data in an inertial navigation system having a Kalman filter and computer-readable storage medium containing instructions to configure a processor to perform the same. The method produces more accurate estimates of the position, velocity and attitude of the inertial measurement unit. The method is fully automatic and enables zero-velocity updates and fixed-azimuth updates to be performed simultaneously. The method may also include a multi-stage filtering process to filter digital compass data when used in an environment with extraterrestrial magnetic field sources. The method may also include a fixed-lag smoother to improve estimates of the position, velocity and attitude of the inertial measurement unit. The method also may include processes to constrain altitude errors.

Abstract: 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.