Abstract: A primary phase measurement device measures a first carrier phase and a second carrier phase of carrier signals received by the location-determining receiver. A secondary phase measurement device measures the third carrier phase and the fourth carrier phase of other carrier signals. A real time kinematic engine estimates a first integer ambiguity set associated with the measured first carrier phase and a second integer ambiguity set associated with the measured second carrier phase. The real time kinematic engine estimates a third ambiguity set associated with the measured third carrier phase and a fourth ambiguity set associated with the measured fourth carrier phase. A compensator is capable of compensating for the inter-channel bias in at least one of the third ambiguity set and the fourth ambiguity set by modeling a predictive filter in accordance with various inputs or states of the filter estimated by an estimator.

Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carder phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.

Abstract: A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.

Abstract: A system and method for providing improved correction information to navigation receivers includes receiving, from a plurality of reference stations at known locations, a plurality of satellite navigation measurements of signals from a plurality of global navigation satellites. A state of the plurality of global navigation satellites is computed based on the received satellite navigation measurements. Baselines, each corresponding to a pair of the reference stations, are identified. For each identified baseline, computing floating and integer values for a double-differenced integer ambiguity. Double-differenced integer ambiguities that satisfy a set of predefined conditions are identified, and the computed state of the plurality of global navigation satellites is adjusted in accordance with an integer value constraint applied to each double-differenced integer ambiguity that satisfies the set of predefined conditions.

Abstract: An antenna includes a first antenna element and a second antenna element, wherein the first antenna element and the second antenna element are both configured in a hook shape. The antenna also includes a first impedance matching circuit coupled to the first antenna element, wherein the first impedance matching circuit includes a first plurality of filters and a second impedance matching circuit coupled to the second antenna element, wherein the second impedance matching circuit includes a second plurality of filters.

Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.

Abstract: A system and method for compensating for faulty satellite navigation measurements. A plurality of measurements in a system is received for a measurement epoch. A Kalman filter is used to calculate a state of the system for the measurement epoch based on the plurality of measurements, wherein the state of the system for the measurement epoch is calculated using a first closed-form update equation. A faulty measurement is detected in the plurality of measurements for the measurement epoch and a revised state of the system for the measurement epoch that compensates for the faulty measurement is calculated, using the calculated state of the system for the measurement epoch as an input to the revised state calculation, and using a revised closed-form update equation comprising the first closed-form update equation modified with respect to the faulty measurement.

Abstract: An adjustable code generator is configurable to generate any of a plurality of spread-spectrum code signals. The adjustable code generator includes a feedback polynomial mask table to contain a set of feedback polynomial masks. Respective feedback polynomial masks of the set correspond to respective spread-spectrum code signals of the plurality of spread-spectrum code signals. The adjustable code generator also includes control logic to select any of the feedback polynomial masks of the set contained in the feedback polynomial mask table, and further includes a shift register to provide, at an output, a respective spread-spectrum code signal that corresponds to a feedback polynomial mask selected by the control logic and to receive feedback generated using the feedback polynomial mask selected by the control logic.

Abstract: A method for mitigating atmospheric errors in code and carrier phase measurements based on signals received from a plurality of satellites in a global navigation satellite system is disclosed. A residual tropospheric delay and a plurality of residual ionospheric delays are modeled as states in a Kalman filter. The state update functions of the Kalman filter include at least one baseline distance dependant factor, wherein the baseline distance is the distance between a reference receiver and a mobile receiver. A plurality of ambiguity values are modeled as states in the Kalman filter. The state update function of the Kalman filter for the ambiguity states includes a dynamic noise factor. An estimated position of mobile receiver is updated in accordance with the residual tropospheric delay, the plurality of residual ionospheric delays and/or the plurality of ambiguity values.

Abstract: A method for mitigating atmospheric errors in code and carrier phase measurements based on signals received from a plurality of satellites in a global navigation satellite system is disclosed. A residual tropospheric delay and a plurality of residual ionospheric delays are modeled as states in a Kalman filter. The state update functions of the Kalman filter include at least one baseline distance dependant factor, wherein the baseline distance is the distance between a reference receiver and a mobile receiver. A plurality of ambiguity values are modeled as states in the Kalman filter. The state update function of the Kalman filter for the ambiguity states includes a dynamic noise factor. An estimated position of mobile receiver is updated in accordance with the residual tropospheric delay, the plurality of residual ionospheric delays and/or the plurality of ambiguity values.

Abstract: In a method of mitigating errors in satellite navigation measurements at a satellite navigation receiver, respective single-frequency signals are received from respective satellites in a plurality of satellites in a satellite navigation system. Pseudorange and carrier-phase measurements corresponding to respective received single-frequency signals are calculated. These calculations include filtering the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, including a position state, a receiver clock state, and a plurality of bias states. Each bias state corresponds to a respective satellite in the plurality of satellites. The filtering includes updating the state vector. An estimated position of the satellite navigation receiver is updated in accordance with an update to the state vector.

Abstract: A method for performing integer ambiguity resolution in a global navigation satellite system is disclosed. A set of ambiguities, which are associated with carrier phase measurements of at least some of the signals received from the satellites in an identified set of satellites, are identified. Integer ambiguities are estimated and a best candidate set and a second best candidate set of integer ambiguity values are determined. Upon determining that the best set of integer ambiguity values fail to meet a discrimination test, each ambiguity for which integer ambiguity values in the best candidate set and second best candidate set fail to meet predefined criteria are removed from the set of ambiguities to produce a reduced set of ambiguities. The integer ambiguities in the reduced set of ambiguities are then resolved and an output is generated in accordance with the resolved integer ambiguities.

Abstract: A satellite navigation device including a flexible radio frequency (RF) receiver is described. The receiver receives a signal that includes at least a first spread-spectrum signal from a first satellite. The receiver has a first channel that includes an analog-to-digital (A/D) converter to sample and quantize the signal and an automatic gain control (AGC) to adjust an amplification of the signal. The A/D converter has a first non-zero quantization threshold magnitude and a second non-zero quantization threshold magnitude. The AGC may adjust a gain in accordance with the first non-zero quantization threshold magnitude. The gain may correspond to a first pre-determined probability of a non-zero sample and the second non-zero quantization threshold magnitude may correspond to a second pre-determined probability of a non-zero sample.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are both configured to receive signals in a first band of frequencies and in a second band of frequencies. Frequencies in the second band of frequencies are greater than frequencies in the first band of frequencies. A first impedance matching circuit, coupled to the first antenna element, includes a first plurality of filters having a first shared component. A second impedance matching circuit, coupled to the second antenna element, includes a second plurality of filters having a second shared component. A feed network circuit is coupled to the first impedance matching circuit and to the second impedance matching circuit and has a combined output corresponding to the signals received by the first antenna element and a second antenna element.

Abstract: A satellite navigation device including a receiver having an adjustable code generator is described. The adjustable code generator is configurable to generate a set of spread-spectrum code signals. Each spread-spectrum code signal has a respective length corresponding to a repetition period. The set of spread-spectrum code signals includes first and second spread-spectrum code signals having distinct first and second lengths.

Abstract: A satellite navigation device including a flexible RF receiver is described. The receiver receives a signal that includes at least one spread-spectrum signal from a first satellite. The receiver has at least a first channel that includes at least two sub-channel circuits. Each sub-channel circuit has at least a first signal generator and a first mixer to receive a respective frequency band in at least the one spread-spectrum signal from the first satellite. The first signal generator provides a respective first signal, having a respective first carrier frequency, to down convert at least a portion of the signal, using the first mixer, to an intermediate frequency that is common to the two sub-channel circuits.

Abstract: A mobile satellite navigation receiver for calculating an offset between a local positioning system and a wide-area satellite positioning system is presented. The mobile satellite navigation receiver determines a first solution of a position of the mobile satellite navigation receiver relative to a first local positioning system, wherein the first local positioning system includes one or more reference receivers at known locations. The mobile satellite navigation receiver determines a second solution of the position of the satellite navigation receiver relative to a wide-area differential satellite positioning system. The mobile satellite navigation receiver then calculates an offset between the first solution and the second solution.

Abstract: A new three-frequency technique for obtaining geometry free, refraction-corrected, ambiguity-resolved, carrier-phase measurements has been described. First, the ambiguities on at least two wide-lane carrier-phase measurement differences are obtained by averaging the corresponding frequency weighted code measurements. These two ambiguity-resolved measurements are then combined into a composite refraction-corrected measurement. The resulting composite measurement is quite noisy due to the amplification of the multipath noise in the original carrier-phase measurements. But this noisy refraction-corrected carrier-phase measurement can be smoothed with another minimum-noise, refraction-corrected carrier-phase composite measurement. The minimum-noise, refraction-corrected composite measurement is constructed from the primary carrier-phase measurements prior to resolving their whole-cycle ambiguities.

Abstract: The present invention includes a method for a combined use of a local positioning system, a local RTK system and a regional, wide-area, or global differential carrier-phase positioning system (WADGPS) in which disadvantages associated with the local positioning system, the RTK and the WADGPS navigation techniques when used separately are avoided. The method includes using a known position of a user receiver that has been stationary or using an RTK system to initialize the floating ambiguity values in the WADGPS system when the user receiver is moving. Thereafter, the refraction-corrected carrier-phase measurements obtained at the user GPS receiver are adjusted by including the corresponding initial floating ambiguity values and the floating ambiguity values are treated as well known (small variance) in subsequent processes to position the user receiver in the WADGPS system.

Abstract: In one embodiment of a positioning system, a transmit element is configured to transmit at least one electromagnetic pulse having a carrier signal frequency. An antenna array with a plurality of receive elements includes at least two receive elements separated by a spacing more than a half wavelength. Each of the at least two receive elements is configured to receive a return signal over a period of time. The return signal includes a return pulse from an object within a detection area of the system. The wavelength corresponds to the carrier signal frequency of the transmitted pulse. A detector is configured to process the return signal from one receive element and the other receive element so as to isolate the return pulse received at each of the at least two receive elements and thereby determine a position of the object in relation to the system.