A transmitter which emits at least two electromagnetic fields. An amplitude of each of the at least two electromagnetic fields has an anisotropy in one plane. An angular arrangement of the receiver relative to the transmitter is determined based on the amplitude of the at least two electromagnetic fields at the position of a receiver.

A transmitter which emits at least two electromagnetic fields. An amplitude of each of the at least two electromagnetic fields has an anisotropy in one plane. An angular arrangement of the receiver relative to the transmitter is determined based on the amplitude of the at least two electromagnetic fields at the position of a receiver.

A transmitter which emits at least two electromagnetic fields. An amplitude of each of the at least two electromagnetic fields has an anisotropy in one plane. An angular arrangement of the receiver relative to the transmitter is determined based on the amplitude of the at least two electromagnetic fields at the position of a receiver.

Systems and methods for a low-frequency radio navigation system are described. The system may include a transmitter comprising a base coded modulator configured to generate a base modulation and a data coded modulator configured to generate a data modulation; wherein the transmitter radiates a continuous, constant-power chirped-FM spread spectrum signal, comprising: the base modulation; and the data modulation, wherein the data modulation is orthogonal to the base modulation. The system may also include a receiver comprising a digital signal processor, wherein at least one matched filter coupled to the digital signal processor, the at least one matched filter configured to decode said base modulation and data-encoded modulation and provide a correlation function for received signals received from at least three geographically-spaced transmitters.

Systems and methods for a low-frequency radio navigation system are described. The system may include a transmitter comprising a base coded modulator configured to generate a base modulation and a data coded modulator configured to generate a data modulation; wherein the transmitter radiates a continuous, constant-power chirped-FM spread spectrum signal, comprising: the base modulation; and the data modulation, wherein the data modulation is orthogonal to the base modulation. The system may also include a receiver comprising a digital signal processor, wherein at least one matched filter coupled to the digital signal processor, the at least one matched filter configured to decode said base modulation and data-encoded modulation and provide a correlation function for received signals received from at least three geographically-spaced transmitters.

Systems and methods for a low-frequency radio navigation system are described. The system may include a transmitter comprising a base coded modulator configured to generate a base modulation and a data coded modulator configured to generate a data modulation; wherein the transmitter radiates a continuous, constant-power chirped-FM spread spectrum signal, comprising: the base modulation; and the data modulation, wherein the data modulation is orthogonal to the base modulation. The system may also include a receiver comprising a digital signal processor, wherein at least one matched filter coupled to the digital signal processor, the at least one matched filter configured to decode said base modulation and data-encoded modulation and provide a correlation function for received signals received from at least three geographically-spaced transmitters.

Systems and methods for a low-frequency radio navigation system are described. The system may include a transmitter comprising a base coded modulator configured to generate a base modulation and a data coded modulator configured to generate a data modulation; wherein the transmitter radiates a continuous, constant-power chirped-FM spread spectrum signal, comprising: the base modulation; and the data modulation, wherein the data modulation is orthogonal to the base modulation. The system may also include a receiver comprising a digital signal processor, wherein at least one matched filter coupled to the digital signal processor, the at least one matched filter configured to decode said base modulation and data-encoded modulation and provide a correlation function for received signals received from at least three geographically-spaced transmitters.