Abstract: To provide sub-meter accuracy in a local positioning system, ranging signals with a high modulation rate of code, such as 30 MHz, or more are transmitted. Code phase measurements may be used to obtain the accuracy without requiring relative motion or real time kinematic processing. The ISM or X-band is used for the carrier of the code to provide sufficient bandwidth within available spectrums. The length of codes used is less than or about a longest length across the region of operation, such as less than 15 kilometers in an open pit mine. The spread spectrum codes from different land-based transmitters are transmitted in time slots pursuant to a time division multiple access scheme for an increase in dynamic range. To avoid overlapping of code from different transmitters, each time slot includes or is separated by a blanking period. The blanking period is selected to allow the transmitted signal to traverse a region of operation.

Abstract: In a local positioning system, the land-based transmitters include free running oscillators or oscillators free of clock synchronization with any remote oscillator. A reference receiver receives the ranging signals from different transmitters and generates timing offset information, such as code phase measurements. The timing offset information is then communicated back to transmitters. The temporal offset information indicates relative timing or phasing of the different transmitted ranging signals to the reference receiver. The transmitters then transmit the temporal offset information with the ranging signals, such as modulating the transmitted code by the timing offset information. A mobile receiver is operable to receive the ranging signals and timing offset information in a same communications path, such as on a same carrier. Position is determined with the temporal offset information and the ranging signals.

Abstract: In a local positioning system, a receiver is adapted for receiving signals from a land-based transmitter. The receiver includes an analog decorrelator for decorrelating the transmitted spread spectrum signals. A down converter connected with an antenna may be spaced away from other portions of the receiver. The down converter down converts received ranging signals and provides them to the remotely spaced receiver portions. A signal line connecting the down converter to the receiver may be operable to transmit any two or more of a reference signal provided to the down converter, the down converted intermediate frequency signals provided to the receiver, and power provided to the down converter. The receiver may be positioned adjacent to or as part of a land-based transmitter. By determining positions of two or more antennas, the location of the associated transmitter is determined.

Abstract: In a local positioning system, the land-based transmitters include free running oscillators or oscillators free of clock synchronization with any remote oscillator. A reference receiver receives the ranging signals from different transmitters and generates timing offset information, such as code phase measurements. The timing offset information is then communicated back to transmitters. The temporal offset information indicates relative timing or phasing of the different transmitted ranging signals to the reference receiver. The transmitters then transmit the temporal offset information with the ranging signals, such as modulating the transmitted code by the timing offset information. A mobile receiver is operable to receive the ranging signals and timing offset information in a same communications path, such as on a same carrier. Position is determined with the temporal offset information and the ranging signals.

Abstract: To provide sub-meter accuracy in a local positioning system, ranging signals with a high modulation rate of code, such as 30 MHz, or more are transmitted. Code phase measurements may be used to obtain the accuracy without requiring relative motion or real time kinematic processing. The ISM or X-band is used for the carrier of the code to provide sufficient bandwidth within available spectrums. The length of codes used is less than or about a longest length across the region of operation, such as less than 15 kilometers in an open pit mine. The spread spectrum codes from different land-based transmitters are transmitted in time slots pursuant to a time division multiple access scheme for an increase in dynamic range. To avoid overlapping of code from different transmitters, each time slot includes or is separated by a blanking period. The blanking period is selected to allow the transmitted signal to traverse a region of operation.

Abstract: Methods and receivers determine a range from radio frequency ranging signals at multiple frequencies. The number of dedicated RF sections and correlation processing power is reduced by multiplexing signals from a sub-set of frequencies onto a common path. The common path provides shared processing, such as down-conversion shared by signals at two different frequencies. The correlation processing power for a three frequency receiver may be the same or similar as for a two frequency receiver since signals for two frequencies share processing as a function of time. Correlation is performed intermittently for signals at two of the frequencies.

Abstract: In a local positioning system, augmentation of the land-based system is provided by receiving signals from a GNSS. The signals from the land-based positioning system have a code phase accuracy better than one wavelength of a carrier of the signals from the GNSS. Different decorrelation may be used for signals from a satellite than from a land-based transmitter, such as using a digital decorrelator for signals from the satellite and an analog decorrelator for signals from a land-based transmitter. The receivers may include both a GNSS antenna and a local antenna. The phase centers of the two antennas are within one wavelength of the GNSS signals from each other. The local antenna is sized for operation in the X or ISM-bands of frequencies. The GNSS antenna is a patch antenna where the microwave antenna extends away from the patch antenna in at least one dimension.

Abstract: A “synchrolite” or rebroadcasting device allows GPS or GNSS navigation signals received at one or several locations to be processed at a separate location. The signals received by the synchrolite are added to a pilot tone and then encoded with a superimposed spread-spectrum code before being rebroadcast. The superimposed code allows signals from different synchrolites to be distinguished during the navigation process.

Abstract: A measurement system and an associated method for determining the positions of multiple antennas to centimeter level accuracy. A plurality of first filters, one filter for each antenna of a plurality of antennas, are each operable to obtain information from a respective one of the plurality of antennas at a primary frequency. A second filter connects with at least one of the plurality of antennas. A processor calibrates biases for the information at the primary frequency with a RF path bias calibration algorithm as a function of an output of the second filter.

Abstract: In a local positioning system, augmentation of the land-based system is provided by receiving signals from a GNSS. The signals from the land-based positioning system have a code phase accuracy better than one wavelength of a carrier of the signals from the GNSS. Different decorrelation may be used for signals from a satellite than from a land-based transmitter, such as using a digital decorrelator for signals from the satellite and an analog decorrelator for signals from a land-based transmitter. The receivers may include both a GNSS antenna and a local antenna. The phase centers of the two antennas are within one wavelength of the GNSS signals from each other. The local antenna is sized for operation in the X or ISM-bands of frequencies. The GNSS antenna is a patch antenna where the microwave antenna extends away from the patch antenna in at least one dimension.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A differential carrier phase global navigation satellite system (GNSS) receiver with multiple antennas uses multiple GNSS carriers to determine position, which can improve the speed of integer searches, for example. In the system, an estimate of delays associated with the transmission paths between the antennas and receiver for at least one of the GNSS frequencies is stored. Typically, these are measures of the phase delay in the transmission paths for two or more of the GNSS frequencies such as in fractional cycles of the GNSS frequencies. Having this information solves problems associated with using multiple carrier frequencies. While cable delays typically have a fixed time delay, the signal paths for the different frequencies are not completely common—even if they were perfectly matched in time, the number of fractional cycles would still be different. Thus, the number of cycles a radio frequency (RF) signal is delayed is different for different frequencies.

Abstract: A vehicle control system with user-guided calibration is presented. In one embodiment, a vehicle control system is presented comprising an output device and circuitry operative to provide an output, via the output device, that guides a user through a plurality of calibration steps in a particular order. The circuitry can additionally or alternatively be operative to determine which of the calibration steps, if any, to present as a next calibration step based on whether a given calibration step is successful. Other embodiments are provided, and each of the embodiments can be used alone or in combination with one another.

Abstract: In a local positioning system, a receiver is adapted for receiving signals from a land-based transmitter. The receiver includes an analog decorrelator for decorrelating the transmitted spread spectrum signals. A down converter connected with an antenna may be spaced away from other portions of the receiver. The down converter down converts received ranging signals and provides them to the remotely spaced receiver portions. A signal line connecting the down converter to the receiver may be operable to transmit any two or more of a reference signal provided to the down converter, the down converted intermediate frequency signals provided to the receiver, and power provided to the down converter. The receiver may be positioned adjacent to or as part of a land-based transmitter. By determining positions of two or more antennas, the location of the associated transmitter is determined.

Abstract: A measurement system and an associated method for determining the positions of multiple antennas to centimeter level accuracy. The system involves minimal incremental hardware cost per additional antenna to be tracked. The primary frequency RF signals are processed by a primary frequency RF section dedicated to each antenna. The secondary frequency RF signals from all the antennas are multiplexed and input to a secondary frequency RF section corresponding to each secondary RF frequency. A correlator derives code and carrier phase for the processed primary and secondary frequency RF signals. A processor thereafter reconstructs the carrier phase for the secondary frequency RF signals. The processor finally uses these reconstructed phases to resolve carrier cycle ambiguities and to determine the position of the antennas.

Abstract: A number of solutions for deriving the line bias are disclosed. Some of these solutions utilize signal processing and judicious selection of the frequency plan used in the position detection systems to either enable the derivation of the line bias, or make the measurements insensitive to line bias.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.