A test device determines a Global Navigation Satellite System (GNSS) signal propagation delay in a GNSS signal distribution system (GSDS) for a radio access network. The test device includes a GNSS receiver and a clock. The GNSS receiver is connected at different times to a reference GSDS with a known signal propagation delay and to a device under test (DUT), including a second GSDS having an unknown signal propagation delay. One pulse per second (1PPS) signals are generated by the GNSS receiver and are compared to determine the unknown signal propagation delay of the DUT.

Methods for commissioning a construction vehicle for machine control operations are provided. A GNSS receiver configured for determining position information, tilt information, and heading information is coupled to a rigid member of the construction vehicle. The commissioning process provides parameters that can be used for tracking and controlling movement of an implement coupled to the construction vehicle during the machine control operations.

Certain implementations of the disclosed technology may include systems and methods for reducing noise in dual-frequency GNSS signal observation. The method can include: receiving, at a GNSS receiver, a first signal and a second signal. At least the second signal includes noise. The first signal is characterized by a first carrier frequency, and the second signal is characterized by a second carrier frequency. The method includes: down converting, sampling, cross-correlating, accumulating, determining ambiguous instantaneous phases, determining non-ambiguous instantaneous phases, producing normalized non-ambiguous instantaneous first phase samples, constructing a normalized first counter rotation phasor, generating a counter-rotated second observable, applying a low pass filter to remove noise; and outputting the filtered second observable.

Certain implementations of the disclosed technology may include systems and methods for reducing noise in dual-frequency GNSS signal observation. The method can include: receiving, at a GNSS receiver, a first signal and a second signal. At least the second signal includes noise. The first signal is characterized by a first carrier frequency, and the second signal is characterized by a second carrier frequency. The method includes: down converting, sampling, cross-correlating, accumulating, determining ambiguous instantaneous phases, determining non-ambiguous instantaneous phases, producing normalized non-ambiguous instantaneous first phase samples, constructing a normalized first counter rotation phasor, generating a counter-rotated second observable, applying a low pass filter to remove noise; and outputting the filtered second observable.

The present disclosure relates to a technical field for airborne navigation and discloses a data acquisition system and method for airborne navigation devices based on unmanned aerial vehicle. The system includes an unmanned aerial vehicle flight control system, a navigation devices test antenna array, a multi-channel signal processing module, a signal acquisition module, an ADS-B transmitting module, a GNSS receiver, a UHF data link receiver, a power module and a ground station. The unmanned aerial vehicle is equipped with corresponding modules to receive signals from ground navigation devices, perform corresponding processing and storage, and transmit data to the ground, at the same time, receive control instructions sent by the ground to complete corresponding monitoring, analysis and inspection.

The present disclosure relates to a technical field for airborne navigation and discloses a data acquisition system and method for airborne navigation devices based on unmanned aerial vehicle. The system includes an unmanned aerial vehicle flight control system, a navigation devices test antenna array, a multi-channel signal processing module, a signal acquisition module, an ADS-B transmitting module, a GNSS receiver, a UHF data link receiver, a power module and a ground station. The unmanned aerial vehicle is equipped with corresponding modules to receive signals from ground navigation devices, perform corresponding processing and storage, and transmit data to the ground, at the same time, receive control instructions sent by the ground to complete corresponding monitoring, analysis and inspection.

An apparatus control method includes: controlling a first frequency band receive chain, of an apparatus, to alternate being on and off with a first duty cycle, the first frequency band receive chain being configured to measure satellite signals within a first frequency band; determining one or more performance criteria; and controlling, based on the one or more performance criteria, a second frequency band receive chain, of the apparatus, to alternate being on and off with a second duty cycle, the second frequency band receive chain being configured to measure satellite signals within a second frequency band.

An apparatus control method includes: controlling a first frequency band receive chain, of an apparatus, to alternate being on and off with a first duty cycle, the first frequency band receive chain being configured to measure satellite signals within a first frequency band; determining one or more performance criteria; and controlling, based on the one or more performance criteria, a second frequency band receive chain, of the apparatus, to alternate being on and off with a second duty cycle, the second frequency band receive chain being configured to measure satellite signals within a second frequency band.

A method for performing in a positioning, navigation, tracking, frequency-measuring, or timing system is provided. The method comprises: providing first and second estimates of at least one system parameter during a first time period, wherein the at least one system parameter has a true value and/or true evolution over time during the first time period; providing a local signal; receiving, at a receiver, a signal from a remote source; providing a correlation signal by correlating the local signal with the received signal; providing amplitude and/or phase compensation of at least one of the local signal, the received signal and the correlation signal based on each of the first and second estimates so as to provide first and second amplitude-compensated and/or phase-compensated correlation signals corresponding to the first and second estimates of the at least one system parameter during the first time period, and; determining which of the first and second estimates is nearer the true value and/or true evolution over time of the at least one system parameter during the first time period, based on a comparison between the first and second amplitude-compensated and/or phase-compensated correlation signals. A computer readable medium and system are also disclosed.

A method for performing in a positioning, navigation, tracking, frequency-measuring, or timing system is provided. The method comprises: providing first and second estimates of at least one system parameter during a first time period, wherein the at least one system parameter has a true value and/or true evolution over time during the first time period; providing a local signal; receiving, at a receiver, a signal from a remote source; providing a correlation signal by correlating the local signal with the received signal; providing amplitude and/or phase compensation of at least one of the local signal, the received signal and the correlation signal based on each of the first and second estimates so as to provide first and second amplitude-compensated and/or phase-compensated correlation signals corresponding to the first and second estimates of the at least one system parameter during the first time period, and; determining which of the first and second estimates is nearer the true value and/or true evolution over time of the at least one system parameter during the first time period, based on a comparison between the first and second amplitude-compensated and/or phase-compensated correlation signals. A computer readable medium and system are also disclosed.