A system for tracking position of objects in an industrial environment includes an interrogator, a transponder, and a processor. The interrogator transmits a signal and provides a first reference signal corresponding to the transmitted signal. The transponder provides a response signal. The interrogator receives the response signal and provides a second reference signal corresponding to the response signal. The processor determines a location of either the interrogator or the transponder, relative to the other, based on the two reference signals.

A distance image sensor includes a light source that generates pulsed light, a light source controller that controls the light source, a pixel circuit including a photoelectric conversion region, charge readout regions, and control electrodes, a charge transfer controller that sequentially applies control pulses to the control electrodes, a signal readout circuit that reads out detection signals of an amount of charge transferred to the charge readout regions and a distance calculator that repeatedly calculates a distance from a difference value between two amounts of charge on the basis of the signals, the light source controller changes generation timing of the pulsed light according to a pseudo random number, and the charge transfer controller changes timings of the application of two control pulses for transferring charge corresponding to the two amounts of charge according to the pseudo random number so that the timings are replaced with each other.

In an ultra-wideband (UWB) communication system comprising a pair of UWB transceivers, an asynchronous two-way ranging method for closely estimating the time-of-flight between the transceivers after the exchange of only 3 messages between the transceivers. In an alternate asynchronous two-way ranging method, the time-of-flight between the transceivers may be closely estimated after the exchange of only 4 messages between the transceivers.

Various avionics systems may benefit from appropriate integration of distance measurement equipment and traffic collision avoidance systems, or the like, using an omnidirectional antenna. A system can include an avionics processor. The system can also include a top antenna receiver configured to connect to a top antenna. The avionics processor can be configured to communicate using the top antenna. The system can further include a bottom antenna receiver configured to connect to a bottom antenna. The avionics processor can be configured to communicate using the bottom antenna. The bottom antenna can be an omnidirectional antenna. The system can additionally include a distance measure equipment receiver configured to be connected to the bottom antenna. The system can also include a distance measure equipment processor configured to measure distance using the bottom antenna.

A ranging method includes a first device that sends a ranging control frame to a second device using a first resource with a lower bandwidth. The ranging control frame includes ranging parameter information. The first device and the second device perform ranging based on the ranging parameter information using a second resource.

Various avionics systems may benefit from the proper handling of diversity with respect to antennas. For example, systems and methods for remote L-band smart antenna distance measuring equipment may benefit from being prepared to provide diversity against interference, such as a multipath interference. A method can include determining which antenna of a plurality of antennas of an aircraft is preferred for communication with respect to distance measuring equipment. The method can also include selecting the antenna based on the determination.

A terrestrial positioning and timing system (TPTS) comprising a ground segment and user segment is disclosed that is comprised of a spread-spectrum based range and bearing reference signal, with respect to a reference time, transmitted by an antenna over a broad region of space; and a spread-spectrum based bearing variable signal with bearing specific modulation referenced to a reference time, transmitted using a scanning antenna over a spatial region of space that is more narrow than the spread-spectrum based range and bearing reference signal transmission spatial area. Various embodiments enable the TPTS station and user to support various position, velocity or time services. Most notably, an embodiment with a single TPTS station, active interrogation/transponder reply, and data delivery subsystem can provide a position, velocity, and time solution for the user. Additional embodiments disclosed provide varying levels of user solutions to include bearing, position, velocity, or time.

The present invention relates to a system for determining a distance, a transponder, a position detection apparatus, and a method therefor. The method for determining a distance comprises providing a position detection apparatus (101), and a transponder (105). The method further comprises generating (201) a pseudo number sequence, transmitting (202) the pseudo number sequence, receiving (203) the pseudo number sequence; modulate (204) the received pseudo number sequence by means of delaying the recieved pseudo number sequence a predetermined number of clock cycles from a group of at least two predetermined number of clock cycles. The method further comprises transmitting (205) the modulated pseudo number sequence, recieving (206) the modulated pseudo number sequence, detecting (207) a path time of the pseudo number sequence, by means of delaying and correlating the generated pseudo number sequence with the received modulated pseudo number sequence, wherein the delay time corresponds to the path time, The method further comprises detecting (208) a clock correction factor for the transponder (105) using the received modulated pseudo number sequence, calculating (209) a flight time of the pseudo number sequence between the position detection apparatus and the transponder by means of the path time, the clock correction factor, and the predetermined number of clock cycles of the transponder, and calculating (210) the distance between said position detection apparatus and said transponder by means of the flight time.

A method for measuring distance includes transmitting a first pair of RF pulses from an airborne interrogator, where the first pair of RF pulses are temporally separated from each other by a first time interval and each of the RF pulses in the first pair of RF pulses has a first pulse waveform. The method also includes receiving a second pair of RF pulses transmitted by a ground transponder. The RF pulses in the second pair of RF pulses have a second pulse waveform characterized by a smoothed concave polygonal function and/or a smoothed concave hexagonal function. The method further includes determining an elapsed time between transmitting the first pair of RF pulses and receiving the second pair of RF pulses and determining a distance between the airborne interrogator and the ground transponder based on at least the elapsed time.

A method for measuring distance includes transmitting a first pair of RF pulses from an airborne interrogator, where the first pair of RF pulses are temporally separated from each other by a first time interval and each of the RF pulses in the first pair of RF pulses has a first pulse waveform. The method also includes receiving a second pair of RF pulses transmitted by a ground transponder. The RF pulses in the second pair of RF pulses have a second pulse waveform characterized by a filtered asymmetric Gaussian function or a smoothed trapezoidal function. The method further includes determining an elapsed time between transmitting the first pair of RF pulses and receiving the second pair of RF pulses and determining a distance between the airborne interrogator and the ground transponder based on at least the elapsed time.