Abstract:
The present invention relates to an antenna system (1) wherein a switch mode power supply (2) is used, and which can detect failure of the GPS module (3) and/or the active antenna (4) present thereon by comparing the duty cycles enabling to run the switch mode power supply (2) by a control unit (5).
Abstract:
A system for estimating carrier phases of radio signals in a satellite navigation system receiver for coordinate determination includes a complex of reference signals (CRS), wherein, in each j th satellite channel, a digital reference signal RefSig j , represents an output phase and frequency-controlled oscillation of a corresponding numerically-controlled oscillator (NCOj) for each j th satellite channel, the phase of the oscillation of the NCO j tracking a carrier signal received from the j th satellite; and an adaptation complex (AC) that, in response to vibration or movement of the receiver, changes (expands or reduces) an effective bandpass of the CRS, producing control signals that determine phase and frequency changes in the corresponding NCO j for reducing dynamic distortions in coordinate measurements
Abstract:
The system provides a global navigation satellite system (GNSS) receiver in a vehicle. The GNSS receiver includes a radio frequency (RF) receiving circuit configured to receive GNSS signals from a plurality of GNSS satellites orbiting Earth at respective azimuth and elevation angles, a memory device storing a predetermined antenna pattern including initial signal to noise ratio (SNR) values for each of the respective azimuth and elevation angles, and a processor. The processor is configured to calculate SNR values of the received GNSS signals, iteratively calculate an updated antenna pattern by combining the calculated SNR values with the initial SNR values, compare further SNR values of further received GNSS signals to the SNR values in the updated antenna pattern to perform at least one of the following: 1) detection and mitigation of multipath signals, 2) estimation of vehicle heading, and 3) determination of a location of the antenna within the vehicle.
Abstract:
Methods and apparatus for generating a test signal for a PNT configuration, and for testing a PNT configuration are disclosed. One such method comprises the steps of using one or more GNSS jamming signal detectors (100) to detect at least three different types of threat signal, each being an RF -based man-made GNSS jamming signal, and recording, to a database, information for the threat signals; receiving, from the database, information for at least one of the threat signals; generating a corresponding threat signal from the received information; and combining the corresponding threat signal with a PNT signal via a signal combiner to generate the test signal.
Abstract:
An approach to joint processing of GNSS signals to determine a receiver location and common mode bias associated with grouped records corresponding to GNSS signals. In this regard, a receiver may acquire signals from a GNSS space vehicle over a relatively long period of time. In turn, records corresponding to received signals may be stored and grouped. The grouping of records may be based on assumptions of a common-mode bias for certain records (e.g., records acquired within a given duration of an observation time period). Upon acquisition of a suitable number of records, an over-determined system may be established that is used in iterative processing to solve for location and/or bias values associated with the respective common-mode bias for each group of records. As such, improved receiver performance may be realized.
Abstract:
Described herein is a receiver for a navigation system, which receives a navigation signal(si(t9))modulated with a pseudorandom sequence along a line-of-sight path and reflected paths. The receiver includes a delay-locked loop(6), which generates a local sequence (cro(n)), and a first correlator (51 ) and a second correlator(53), which operate in open-loop mode and generate a first correlation signal.
Abstract:
Systems and methods for detecting the failure of a precision time source using an independent time source are disclosed. Additionally, detecting the failure of a GNSS based precision time source based on a calculated location of a GNSS receiver is disclosed. Moreover, the system may be further configured to distribute a time derived from the precision time source as a precision time reference to time dependent devices. In the event of a failure of the precision time source, the system may be configured to distribute a time derived from a second precision time source as the precision time signal during a holdover period.
Abstract:
Navigation system receiver, and test circuits and methods for determining drift profile of a receiver clock in the navigation system receiver are disclosed. In an embodiment, the navigation system receiver (100) includes a clock source (130) configured to generate a receiver clock for the navigation system receiver and a test circuit (170). The test circuit is configured to facilitate determination of a drift profile associated with the receiver clock based on detection and tracking of a test signal received by the test circuit, where the test signal comprises at least one continuous wave (CW) signal.