Methods and systems for estimating the position of an object such (as a vehicle) are disclosed. The method comprises transmitting a first V2X message from the object to a plurality of spaced apart units; and receiving a set of V2X response messages from at least two units in response to the first V2X message. Each response message comprises an identifier of the object, an identifier of the unit from which the response message was sent, and temporal information associated with the times of receiving a previous V2X message at the unit and transmitting a previous V2X response message from the unit. The position of the object is estimated based on the information contained in the set of V2X response messages and the times of transmitting the previous V2X message from the object and receiving the previous set of V2X response messages at the object.

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 received 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, receiving (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 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.

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.

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.

In a distance estimating system, a first terminal transmits a response request signal and successively transmits impulse signals as synchronization signals, and a second terminal receives the response request signal, generates response data based on the response request signal, shifts a bit, which is a transmission target in a bit string as the response data, by one toward a rear side from a leading bit to a trailing bit each time the synchronization signal is received, transmits the impulse signal in a case where a value of a bit that is a transmission target at a time of reception of the synchronization signal is a predetermined value. The first terminal further measures a round-trip time, specifies a flight time of the impulse signal, and estimates a distance to the second terminal based on the flight time and a propagation velocity of the impulse signal.

Various communication systems may benefit from suitable architectures. For example, L-band radio frequency (RF) architectures may be beneficial to systems including avionics systems. A system can include a mode-s function as well as a traffic alert and collision avoidance system function separate from the mode-s function. The system can further include a directional antenna in reception and transmission connection with the traffic alert and collision avoidance system function. The system can additionally include an omni-directional antenna in reception and transmission connection with the mode-s function.

Systems, methods, and apparatuses for determining the distance between two positions are disclosed. The system includes a correlator, a first receiver, and a second receiver. The first and second receivers each include: an antenna, a steering mechanism, and a processor. The steering mechanism steers the antenna in an azimuthal direction and an elevation direction. The processor is configured to (i) control the steering mechanism, (ii) receive data recorded by the antenna from a plurality of sources, (iii) time-stamp the data recorded by the antenna, and (iv) control the transmission of the time-stamped data to the correlator. The correlator is configured to receive the time-stamped recorded data from the first receiver and the second receiver, and calculate a distance between the first receiver and the second receiver based thereon.

A method, system, and computer-readable medium for performing a hazard analysis of navigation aid equipment using an external safety monitor. Aspects include monitoring performance of the navigation aid equipment. In addition, determination is made if an improper performance of the navigation aid equipment is detected. Furthermore, removal of a signal from an antenna of the navigation aid equipment may occur when improper performance of the navigation aid equipment is detected.

A method, system, and computer-readable medium for performing a flight check of one or more navigational aid systems. Aspects include determining, using an unmanned aircraft, an accuracy of signals transmitted by a localiser. Aspects also include determining, using the unmanned aircraft, an accuracy of signals transmitted by a glide slope station.