Abstract: Methods and apparatus are provided for improving the resilience of a network of positioning-unit devices to failure of the reference device that controls the network timebase via timing information in its signal. In certain embodiments a predetermined one of the positioning-unit devices is configured to monitor the reference signal, assess serviceability of that signal and take control of the network if it determines that signal is unserviceable. Continuity of network synchronisation is thereby maintained despite the reference signal being unserviceable. Preferably the predetermined positioning-unit device is configured to obtain information on the reference signal from at least one other positioning-unit device for assessing reference signal serviceability.

Abstract: Apparatus and methods are presented for synchronising a slave device signal to a reference timebase, in situations where the slave device lacks knowledge of the propagation delay for signals from the reference device, e.g. if the positions of one or both of the devices are unknown or classified, or the inter-device signal propagation distance is otherwise a-priori unknown. Reference signal propagation delay is determined using an exchange of signals between the devices, with each device using a differencing procedure for eliminating effects of receiver line bias and other hardware delays. In another aspect an exchange of signals between the devices is used to detect a time residual arising from an inaccurate propagation delay estimate. The synchronisation methods can be applied to a plurality of slave devices for providing a synchronised location network. In certain embodiments signals are transmitted wirelessly, while in other embodiments they are transmitted via a fixed line.

Abstract: Apparatus and methods are presented for characterising the environment of a user platform. In certain embodiments RF signals are transmitted and received through an antenna array having a plurality of elements activated in a predetermined sequence, and received signals are manipulated with round-trip path corrections to enhance the gain of the array in one or more directions. Objects in those directions are detected from the receipt of returns of transmitted signals, and the manipulated received signals processed to estimate range to those objects. In other embodiments RF signals transmitted by one or more external transmitters are received and manipulated to enhance the gain of a local antenna array or antenna arrays associated with the one or more transmitters to enhance the gain of the arrays in one or more directions. Objects in those directions are detected from the receipt of reflected signals from the transmitters, and the manipulated received signals processed to estimate range to those objects.

Abstract: Apparatus and methods are presented for synchronising a slave device signal to a reference timebase, in situations where the slave device lacks knowledge of the propagation delay for signals from the reference device, e.g. if the positions of one or both of the devices are unknown or classified, or the inter-device signal propagation distance is otherwise a-priori unknown. Reference signal propagation delay is determined using an exchange of signals between the devices, with each device using a differencing procedure for eliminating effects of receiver line bias and other hardware delays. In another aspect an exchange of signals between the devices is used to detect a time residual arising from an inaccurate propagation delay estimate. The synchronisation methods can be applied to a plurality of slave devices for providing a synchronised location network. In certain embodiments signals are transmitted wirelessly, while in other embodiments they are transmitted via a fixed line.

Abstract: Apparatus and methods are presented for characterising the environment of a user platform. In certain embodiments RF signals are transmitted and received through an antenna array having a plurality of elements activated in a predetermined sequence, and received signals are manipulated with round-trip path corrections to enhance the gain of the array in one or more directions. Objects in those directions are detected from the receipt of returns of transmitted signals, and the manipulated received signals processed to estimate range to those objects. In other embodiments RF signals transmitted by one or more external transmitters are received and manipulated to enhance the gain of a local antenna array or antenna arrays associated with the one or more transmitters to enhance the gain of the arrays in one or more directions. Objects in those directions are detected from the receipt of reflected signals from the transmitters, and the manipulated received signals processed to estimate range to those objects.

Abstract: A device and method are provided for forming a beam of a transmit antenna array in the direction of a positioning receiver. Since the beam of the transmit antenna array is formed remotely by the positioning receiver, the received gain of the incoming positioning signal is maximised while signals from other directions are attenuated, thereby mitigating any unwanted effects of multipath. Depending on the number of elements in the transmit antenna array and their physical distribution, the width of the beam can be made finer such that the positioning receiver only requires a simple omni-directional antenna to achieve an accurate positioning solution.

Abstract: Methods and devices are presented for synchronizing positioning signals in a kinematic location network. In particular, methods and devices are presented for synchronizing a unique positioning signal generated by a positioning-unit device to a reference positioning signal generated by a reference transmitter, where the positioning-unit device and the reference transmitter are moving relative to each other. In certain embodiments the reference transmitter or the positioning-unit device, or both, self-monitor trajectory data comprising one or more of location, velocity or acceleration, e.g. using inertial navigation systems, and broadcast that data in their positioning signals. The trajectory data enables estimation of Doppler shifts and propagation delays associated with the positioning signals, allowing measurement and correction of clock drift for synchronization of the positioning signals.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: A device and method are provided for forming a beam of a transmit antenna array in the direction of a positioning receiver. Since the beam of the transmit antenna array is formed remotely by the positioning receiver, the received gain of the incoming positioning signal is maximised while signals from other directions are attenuated, thereby mitigating any unwanted effects of multipath. Depending on the number of elements in the transmit antenna array and their physical distribution, the width of the beam can be made finer such that the positioning receiver only requires a simple omni-directional antenna to achieve an accurate positioning solution.

Abstract: Methods and devices are presented for synchronizing positioning signals in a kinematic location network. In particular, methods and devices are presented for synchronizing a unique positioning signal generated by a positioning-unit device to a reference positioning signal generated by a reference transmitter, where the positioning-unit device and the reference transmitter are moving relative to each other. In certain embodiments the reference transmitter or the positioning-unit device, or both, self-monitor trajectory data comprising one or more of location, velocity or acceleration, e.g. using inertial navigation systems, and broadcast that data in their positioning signals. The trajectory data enables estimation of Doppler shifts and propagation delays associated with the positioning signals, allowing measurement and correction of clock drift for synchronization of the positioning signals.

Abstract: A device and method are provided for forming a beam of a transmit antenna array in the direction of a positioning receiver. Since the beam of the transmit antenna array is formed remotely by the positioning receiver, the received gain of the incoming positioning signal is maximized while signals from other directions are attenuated, thereby mitigating any unwanted effects of multipath. Depending on the number of elements in the transmit antenna array and their physical distribution, the width of the beam can be made finer such that the positioning receiver only requires a simple omni-directional antenna to achieve an accurate positioning solution.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: A device and method are provided for forming a beam of a transmit antenna array in the direction of a positioning receiver. Since the beam of the transmit antenna array is formed remotely by the positioning receiver, the received gain of the incoming positioning signal is maximised while signals from other directions are attenuated, thereby mitigating any unwanted effects of multipath. Depending on the number of elements in the transmit antenna array and their physical distribution, the width of the beam can be made finer such that the positioning receiver only requires a simple omni-directional antenna to achieve an accurate positioning solution.

Abstract: A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.

Abstract: An attitude system that includes a radiating means which moves predeterminately through three-dimensional space, such that a cyclic Doppler is superimposed upon a transmitted signal; receiving this transmitted signal through a receiving means which moves predeterminately through three-dimensional space, such that a cyclic Doppler is superimposed upon the received signal; analyzing the movement of the receive means in relation to the radiating means by interpreting the received cyclic Doppler; and determining attitude based on the interpreted Doppler. Or alternatively, adjusting the movement of the receive means in three-dimensional space so the superimposed cyclic Doppler is minimized on the received signal and; determining attitude based on the adjustment required to bring the receive means and radiating means into an alignment.

Abstract: The system comprises a positioning-unit device (PUD) that receives, from other PUDs and other signal sources, one or more positioning signals, which each have carrier, code and data componcuts. In response to the received positioning signals and using their known locations, the PUD generates a unique positioning signal, which similarly has carrier, code and data components, all of which are respectively chronologically synchronized to the counterpart components of the received positioning signals. Once synchronized, other PUDs entering the network use the unique positioning signal as a reference, providing a time-coherent network of positioning signals that propagate a reference timebase over a geographical area.

Abstract: Generating frequency coherence between a received reference positioning signal carrier component transmitted by at least one reference transmitter and a unique positioning signal carrier component generated by a positioning-unit device. The positioning-unit device receives a reference positioning signal and measures a frequency offset of the reference positioning signal carrier component relative to a common oscillator. Once a frequency offset is measured, the positioning-unit device adjusts a frequency steerable clock by an amount derived from the measured frequency offset. The positioning-unit device then generates a unique positioning signal carrier component at an aligned carrier frequency with the reference positioning signal carrier component. Furthermore, the positioning-unit device continuously adjusts the unique positioning signal carrier component by applying the measured frequency offset to the frequency steerable clock, which is reference to the common oscillator.