Topcon Gps, LLC

Magellan Corporation

Topcon Positioning Systems, Inc.

Topcon Positioning Inc.

Victor Abramovich Veitsel

Mark Isaakovich Zhodzishsky

Javad Ashjaee

Lionel Jacques Garin

Andrey Vladimirovich Veitsel

Stanislov Sila-Novatisky

Mark Zhodzicshsky

Sergey Yudanov

Michail Y Vorobiev

Alexey Zinoviev

Mark Isaakovich Zhodzishky

Alexey Vladislavovich Zhdanov

Vladimir Viktorovich Beloglazov

Victor Andreevich Prasolov

Vladimir Victorovich Veitsel

Dmitry Anatolyevich Rubtsov

Andrey Valerievich Plenkin

Igor Anatolyevich Orlovsky

Dmitry Pavlovich Nikitin

Farbod Kamgar

Vladimir Victorovich Beloglazov

Alexey S Lebedinskiy

Roman Valerievich Kurynin

Roman Anatolyevich Nevzorov

Vladimir Viktorovich Veitsel

Alexander Kirsanov

Oleg Potekhin

Michael Yu Vorobiev

Andrew V Veitsel

Sergey N Pushkarev

Andrey V Narizhny

Alexey Lebedinskiy

Sergey Borisovich Yudanov

Vladimir Veitsel

A GNSS receiver includes an antenna receiving GNSS signals from a plurality of GNSS satellites; a plurality of channels, each channel processing a single GNSS signal from a single GNSS satellite, and outputting a pseudo-phase of a signal carrier frequency of the single GNSS signal; a block for solving the navigation task based on the pseudo-phases of multiple GNSS signals; each channel including a detector of shadowing of the corresponding GNSS signal; each channel including a weight calculator specifying a relative weight of the single GNSS signal in solving of the navigation task; and each channel including a circuit for recovering a tracking of the shadowed GNSS signal once the shadowing ends. The recovering includes generating guiding indications that enable reducing a time to re-acquire the shadowed GNSS signal.

Shadow recovery of a single satellite signal in a GNSS receiver

A correction phase locked loop (CPLL), including a signal processing unit that receives a digitized input signal from a satellite, the signal processing unit comprising (a) a primary correlator and primary discriminator, connected in series and generating a main error signal Zfrom the digitized input signal; (b) a correction correlator and a correction discriminator connected in series and generating a correction signal Z; and (c) an adder for adding the main error signal Zand the correction signal Zto produce a common error signal Z. A loop filter filters the common error signal Z to produce a corrected error signal that is used for frequency-phase control of a Numerical Control Oscillator (NCO). The NCO generates two mutually orthogonal output reference signals whose phase is substantially free of multipath errors.

Apparatus for correcting multipath errors in carrier phase measurements of a navigation receiver

The effects of shock and vibration on a navigation receiver processing satellite signals received from global navigation satellites are reduced by controlling the frequency and the phase of the individual numerically controlled oscillator in each individual satellite channel. The frequency is controlled by an individual frequency control signal based on individual correlation signals generated in an individual satellite channel. The phase is controlled by a common phase control signal or a combination of a common phase control signal and an individual phase control signal. The common phase control signal is based on all the correlation signals generated in all the satellite channels processed by a separate common broadband quartz loop (SCBQL). An individual phase control signal is based on the individual correlation signals generated in an individual satellite channel.

Method for building a vibration-resistant navigational satellite signals receiver and a device for receiving and processing navigation signals

A navigation receiver processes signals transmitted by global navigation satellites and received by a set of antenna units. Each antenna unit is connected to a separate input port of an antenna multiplexer switch. Satellite signals received from each antenna unit are consecutively switched to the input of a common radiofrequency processing module. A common signal correlator generates a common in-phase correlation signal from the satellite signals received from all the antenna units. The common in-phase correlation signal is processed by a data processing module to demodulate information symbols from the received satellite signals. The common in-phase correlation signal is also processed by phase-lock loops and delay-lock loops to generate carrier phases and code delays from the received satellite signals. Embodiments are described in which, along with the common in-phase correlation signal, common functional blocks or hardware are used to process the satellite signals received from all the antenna units.

Navigation receiver for processing signals from a set of antenna units

The energy potential of a receiver receiving signals from a navigation satellite is calculated according to an algorithm which is a function of an estimate of the mean and an estimate of the variance of a correlation signal. Improving the accuracy of measuring the energy potential may be achieved by improving the variance estimate. The variance estimate may be determined from measurements of the correlation signal over long time intervals during operation of the receiver. The variance estimate may also be determined during a calibration procedure, or by mathematical modeling of the receiver.

Measurement of energy potential (signal-to-noise ratio) in digital global navigation satellite systems receivers

Base data received at a rover receiver is extrapolated to a rover measurement time referenced to a clock in the rover receiver. The base data comprises a plurality of base parameters, such as pseudo-ranges and full phases, calculated at base epochs from data received from navigation satellites. Base data is decomposed into a computed component, a common component, and an information component. Only the information component is extrapolated, thereby increasing the extrapolation time interval (during which base data are missing) over which an acceptable accuracy in determination of rover coordinates may be provided. The extrapolated base data is calculated by adding the computed component updated to the rover measurement time, the information component extrapolated to the rover measurement time, and the common component. A second-order recursive digital filter is used to generate the extrapolation function.

Base data extrapolator to operate with a navigation receiver in real-time kinematic (RTK) and differential global positioning system ( DGPS) modes

Disclosed is a system and method for processing signals received from different global navigation satellite systems. The receiver includes a number of universal digital channels. The universal digital channel can be used to receive and process different code signals of each of the three navigation satellite systems GPS, GLONASS, and GALILEO. The universal digital channels have the same structure. Each of them can be tuned to receive different signals. The core of the universal digital channel is a code generator and a universal strobe generator.

Universal digital channel for receiving signals of global navigation satellite systems

Disclosed is a method for determining coordinates of a mobile rover. The method includes determining a vector of one-shot code coordinates of the mobile rover. The method also includes determining a vector of phase increments by determining full phase differences for each navigation satellite in a plurality of navigation satellites in view at a discrete time interval (called a time epoch) and at a previous time epoch in a plurality of time epochs. A vector of radial range increments is determined from the full phase differences. A vector of rover phase coordinate increments is also determined using the vector of radial range increments. The vector of one-shot code coordinates and the vector of rover phase coordinate increments are then filtered to determine, at each time epoch, smoothed code coordinates of the mobile rover. Measured phase increments are cleared up from abnormal measurements.

Method and apparatus for determining smoothed code coordinates of a mobile rover

Disclosed is a method and apparatus for determining the relative position of a mobile unit that moves from an initial location to a plurality of successive positions. The mobile unit receives signals from a plurality of navigation satellites and tracks the carrier phases of the signals during movement. For each of the received signals, carrier phase increments are calculated over a plurality of epochs. Anomalous carrier phase increments are determined and eliminated from further calculations. The non-eliminated carrier phase increments are then used to calculate coordinate increments for each of the time epochs. If, after elimination, the remaining number of carrier-phase increments is less than a threshold for a particular epoch, then coordinate increments for the particular epoch may be extrapolated using data from prior epochs. In various embodiments, least squares method and Kalman filtering may be used to calculate the coordinate increments. The coordinate increments may then be summed over a plurality of time epochs in order to determine a position of the mobile unit relative to its initial position.

Position determination using carrier phase measurements of satellite signals

Disclosed is an adaptive receiver configured to receive signals from satellite navigation systems to determine receiver coordinates and configured to use a co-op tracking system to evaluate full phases of carrier phases for N navigation satellites in view. The adaptive receiver includes channels with autonomous wideband phase lock loops (PLLs) in a guiding status. The wideband PLLs are configured to track phases of carrier signals from satellites having high SNR and configured to produce control codes for target designations of varying carrier frequency. The adaptive receiver also includes channels with narrow-band PLLs in a guided status. The narrow-band PLLs can track phases of carrier signals of satellites with low SNR and are configured to use target designations from the wideband PLLs in guiding status and a prediction of frequency change caused by satellite movement. The adaptive receiver also includes channels with open PLLs in a standby mode.

Method and apparatus for adaptive processing of signals received from satellite navigation systems

A method and apparatus for estimating the changing frequency of a signal received by a satellite receiver from, illustratively, positioning system satellites is disclosed that enables a more accurate measurement of the change in frequency of that signal due to movement of the satellite receiver relative to those satellites. The system includes a PLL having a numerically controlled oscillator (NCO) and a filter of frequency estimates (FFE). In operation, an analog signal is received at the satellite receiver and the PLL tracks the changing signal frequency and outputs non-smoothed frequency estimates into the FFE. The FFE then smoothes noise in the signal to produce a more accurate smoothed frequency estimate of the input signal. Comparing multiple estimates over time allows Doppler shift of the signal frequency received by the satellite receiver to be calculated more precisely, thus resulting in more accurate satellite receiver velocity vector determinations and, hence, position measurements.

Method and apparatus for determining changing signal frequency

Disclosed is a method and apparatus for multipath mitigation using an antenna array. An antenna array made up of a plurality of antennas is used to receive satellite signals from satellites. Various configurations of antenna arrays is disclosed, including a linear vertical antenna array and a horizontal antenna array in which the antenna elements are located in a horizontal plane. A switch sequentially connects each of the antenna outputs to a single processing path to generate a common additive signal. The common additive signal is provided to satellite channel processors, each of which processes the signals from an associated satellite. A phase shift correction signal associated with each of the antennas is generated and synchronously applied to a carrier phase reference signal. A blocking signal may be applied to the satellite channel processors in order to block the processing of signals from an unwanted satellite.

Method and apparatus for multipath mitigation using antenna array

A method and apparatus for detecting and correcting anomalous measurements in a satellite navigation receiver is disclosed. Anomalous measurements are detected using the redundancy of observed satellite signals, or by analyzing the relationship between phase measurements at two frequencies when using dual frequency receivers. Upon determination that an anomalous measurement exists, the particular channel on which the anomalous measurement has occurred is determined. In addition, the extent of the anomalous measurement is estimated to produce an estimated error value. This information may then be used by the satellite navigation receiver in order to increase the accuracy of a navigation task.

Method and apparatus for detecting anomalous measurements in a satellite navigation receiver

GPS and GLONASS Satellites broadcast code signals which are modulated onto respective carrier signals, and which are received by two receivers on Earth. The first receiver is situated at a point with known coordinates. The results of its measurements are transmitted to a user at a second receiver through a connection link, the user wanting to know the position of the second receiver. The measurements of two receivers are related to a common time moment by extrapolating measurement data that has arrived through the connection link with a delay. An extrapolating unit examines the measurements to find and discard measurements with abnormal errors, and generates extrapolated measurement data (e.g., predictions) for the common time based upon the most reliable data. This enables the measurements of code delays and carrier phase shifts in the satellite signals received by two receivers to be processed for the position of the second receiver.

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Moscow, Russia

Victor Abramovich Veitsel