Abstract: A method for distance measurement and data transmission in a continuous wave radar system is described. A continuous wave radar system has a transmit and receive module and at least one transponder device, a mobile control and monitoring device and an HMI system. Transponder devices are searched for with the aid of an unmodulated continuous wave signal as an interrogation signal, such that the transponder device can send a radio response signal to the transmit and receive module in response to the interrogation signal, as a result of which a data transmission takes place from the transponder device to the transmit and receive module. Upon completion of the data transmission a frequency-modulated continuous wave signal is generated in order to measure, on the basis thereof, a distance between the transponder device and the transmit and receive module.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: A method and system for a Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth signal in VHF of lower frequency range, which minimizes propagation loss and loss of accuracy of the RF locating signals. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF signal penetration and an increased accuracy by using VHF bands. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

Abstract: A multifunction radio for receiving radio signals from and sending transmissions to multiple radio systems comprises an antenna and a transmit/receive switch coupled to the antenna. The radio further comprises a receiver section coupled to the transmit/receive switch and configured to receive radio signals from one or more multiple radio systems. The receiver section includes a digital downconverter configured to digitally downconvert radio signals sent from one or more of the multiple radio systems and a digital signal processor coupled to the digital downconverter for processing the downconverted signals. A transmitter section is coupled to the transmit/receive switch and configured to generate a transmission signal for reception by one or more of the multiple radio systems.

Abstract: A combined transponder and DME system for use in an aircraft. An L Band transmitter is shared between transponder and DME.

Abstract: A transponder unit of a DME ground apparatus receives an interrogation signal and converts the same to an IF signal. The unit performs analog-to-digital conversion on the IF signal, generating a digital interrogation signal. The unit calculates two detected outputs whose frequencies are ±900 kHz deviated with respect to the center frequency of the digital interrogation signal. Then, the transponder unit compares the two detected outputs and the digital interrogation signal in terms of magnitude, thereby to determine whether a response signal should be transmitted.

Abstract: The transponder unit provided in a DME ground apparatus detects the transmission rate at which to transmit the pulse-pairs constituting a response signal. The threshold of the reception level of the pulse detection unit provided in the transponder unit is raised as the transmission rate increases.

Abstract: The field of the invention is that of navigation systems serving aboard an aircraft, to determine the position of the aircraft on the basis of measurements of distance separating the aircraft from radionavigation beacons delivered by equipment of the DME type (Distance Measuring Equipment).

Abstract: An electronic device includes a main body, a drive mechanism configured to move the main body, a detector having a plurality of sensors mounted in the main body for detecting distances to an object which is present in a space around the main body, a calculator configured to calculate a direction of the object relative to the main body based on the detected distances, and a controller configured to control the drive mechanism to change an orientation of the main body dependent on the calculated direction.

Abstract: A combined transponder and DME system for use in an aircraft. An L Band transmitter is shared between transponder and DME.

Abstract: A transmitting apparatus comprises a generator for generating a pulse signal having a waveform approximated to the Gaussian error function at a prescribed timing, a transmitter for power-amplifying a pulse signal generated by the generator, and transmitting the amplified pulse signal, an evaluator for extracting a pulse waveform part from the power-amplified pulse signal, comparing the extracted pulse waveform part with an ideal waveform so as to obtain an error amount between the pulse waveform part and the ideal waveform, and evaluating whether or not the error amount is within a prescribed error range, and a controller for causing the generator to subject the waveform of the pulse signal to correction in such a manner that the error amount becomes smaller each time an evaluation result of the evaluator is that the error amount is out of the prescribed error range.

Abstract: The invention addresses the disadvantage of RFID scanning by maintaining the relative physical order of tags simultaneously scanned. The novelty of the invention includes a forwarding mechanism applied to the RFID tags and an aggregation of the received tag information. The received information is then used to calculate relative ordering information. Our system leverages both reader-to-tag and tag-to-tag communication. Each tag in the invention can measure the received signal strength and the ID of the sender. Tags respond to received signals by transmitting their ID and a payload consisting of the ID & signal strength of the previous sender as well as the payload received from the previous sender. The reader then aggregates this information from which is calculated the relative physical ordering of the tags based on the aggregated information.

Abstract: An attack is activated in a receiver amplifier of an interrogator whenever an amplified input signal exceeds an attack threshold voltage value Vatt, and the receiver amplifier at least during a waiting period, the length of which preferrably equals the double length of the longest time interval between adjacent pulses in a transponder data wave packet, after the end of the attack does not respond in the sense of setting the gain. However, the amplifier responds with a decay activated after the lapse of the waiting period, which started when the instantaneous amplified signal value for the last time after the end of the attack exceeded a waiting threshold voltage level Vw. The decay rate is of the same order of magnitude as the attack rate. The improved method for automatically setting the gain renders it possible that the interrogator receiver within the non-contacting identification system practically does not change the essential characteristics of the input signal.

Abstract: A method for determining the relative position between two or more objects in a marine environment, including waterways, of which at least one object can be maneuvered relative to one or more other objects. At least one interrogator is arranged on one or more of the objects and sends a radio wave signal to at least one transponder arranged on one or more of the other objects. The novel method is the use of a FMCW radar in the interrogator, the use of the transponders for including identity tags into the signals to be reflected to the interrogator, and attitude determination. A system for this determination is also described.

Abstract: An instrumented navigation system for aiding a towboat and barge configuration in the entry and traversal of a lock located on a waterway or for navigation around other structures, such as bridge piers or docks. The system consists of wirelessly linked computers on the towboat and the lock which display navigational charts showing the position of the tows as they approach and enter the locks. The computers are also linked to sensors which send information, such as the speed and position of the tows, to the computers for display.

Abstract: A robot for freely moving about in an environment where there is an obstacle. The robot includes a communication section transmitting by wireless an image taken by a camera to a base station, and via the base station to a communication terminal making a radio communication with the base station, and receiving by wireless movement target position information specified on the image by an operation of the communication terminal via the base station, and a motion control section that moves the robot up to a movement target position specified by the movement target position information acquired in the communication section.

Abstract: The invention relates to a method of suppressing pulsed signals in particular of DME or TACAN type present in the radio signals received (Ue) by a radio-frequency receiver, characterized in that the reception frequency band of the receiver is divided into frequency sub-bands corresponding to the transmission channels of the pulsed signals, in that the presence of the pulsed signals and the transmission channel of said pulsed signals in the frequency sub-bands are detected, and in that the frequency sub-band comprising the detected pulsed signals is filtered over the duration of the pulsed signal so as to eliminate said pulsed signals pulse type.

Abstract: Methods and apparatus are provided for detecting an object in the projected path of a vehicle. The apparatus comprises a yaw sensor configured to determine the yaw of the vehicle and an object detection sensor configured to evaluate an Actual Range Bin and to produce obstruction data if an object is sensed within the Actual Range Bin. The apparatus also comprises a controller that is configured to receive the yaw determined by the yaw sensor and determine a projected path of the vehicle based at least in part upon the yaw. The controller is also configured to determine a True Range Bin based at least in part upon the projected path of the vehicle and the Actual Range Bin. The controller is further configured to receive the obstruction data from the object detection sensor and determine if the object is within the True Range Bin.

Abstract: A portable apparatus to track an object includes a transmitter adapted to sending pulses of known duration and intensity; a receiver having one or more antennas to receive the pulses of known duration and intensity from the transmitter, the receiver and the transmitter having synchronized clocks to determine signal propagation time and distance, and wherein an alarm is generated if the determined distance exceeds a preset value.

Abstract: A method for dynamically verifying a multiple beam antenna placed on a craft including a device for determining the position and course of the craft and a transmitter that via the antenna can emit pulsed signals. At least two transponders are placed in different directions round a measuring area with each transponder receiving a pulsed signal of at least one frequency, different for the different transponders, from the antenna. The transponders are adapted to send, after receiving the pulsed signal, a corresponding pulsed signal to the measuring station in such a manner that the transponder sending the signal can be determined at the measuring station which evaluates how well the antenna has managed to direct the radiated energy in the desired directions.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation section 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: A transceiver for short-pulse radar applications is disclosed in which a shift register or the like is used to collect return signal information in a manner to reduce the number of transmit pulses needed and to increase the speed of determining the positions of multiple scattering objects. In addition, there is also disclosed cooperating transceivers arranged as transponders similarly utilizing shift registers or other pulse sampling techniques to accurately determine the linear distance between them based on relationships between or among propagation time, measured offsets, and internal clock skews. Corresponding methods are also disclosed.

Abstract: A multi-frequency RFID remote communication system is provided that includes a plurality of RFID tags configured to receive a first signal and to return a second signal, the second signal having a first frequency component and a second frequency component, the second frequency component including data unique to each remote RFID tag. The system further includes a reader configured to transmit an interrogation signal and to receive remote signals from the tags. A first signal processor, preferably a mixer, removes an intermediate frequency component from the received signal, and a second processor, preferably a second mixer, analyzes the IF frequency component to output data that is unique to each remote tag.

Abstract: A system, apparatus, and method for determining the distance between two objects using an indirect propagation delay measurement is disclosed. A frequency hopping scheme (such as the Bluetooth™ technology) is used to measure the relative phase offset of the received signal between the various frequencies. For a given distance between the objects, the phase offset vs. frequency curve is a straight line with the slope dependent upon the measured distance. After the phase of the received signals is detected, the data is plotted on a curve and the slope is calculated. A wireless slave device remains phase locked with another device in a half-duplex communication mode by employing a low-drift phase locked loop employing a voltage controlled crystal oscillator. The phase locked loop further employs a mechanism that provides immunity from transitory phase slip at a time when the loop is opened.

Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art.

Abstract: A method, apparatus, article of manufacture, and a memory structure for tracking assets. The method comprises the steps of generating a magnetic field at the base station, receiving a radio signal transmitted from the remote station disposed at a location, and determining a distance from the base station to the location from the received radio signal transmitted from the remote station. In another embodiment of the invention, the method comprises the steps of remotely sensing a magnetic field generated by a base station, measuring an intensity of the sensed magnetic field, and transmitting a radio signal from the remote station to the base station as an indication of a distance between the base station and the remote station.

Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art. By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation section 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time.

Abstract: The present invention provides an apparatus, method, and system for determining a time of arrival (TOA) and time differences of arrival (TDOA) of a transmitted signal {S} receivable at different locations of known spatial coordinates. The system comprises a first transmitter 10 with a respective antenna feed point positioned at an a priori unknown location P and emitting a first signal {S}. The system includes furthermore a set of transceivers or transponder units 20, 30 comprising first receivers 22, 32 for receiving first signals {S} by means of respective antennas with feed points located at known locations Ln. Such system also comprises second transmitters 26, 36 emitting respective derived second signals {{tilde over (S)}n} after known and scheduled respective time intervals &dgr;n as measurable between the feed points of said respective first receiving antennas located at known locations Ln and respective second transmitting antenna located at locations L′n.

Abstract: A system 100 is disclosed for monitoring the position of one or more RFID tags 201. The system has a detector 301 incorporating circuitry 304 for detecting changes in the range of an RFID tag 201 from the detector and for triggering an alarm 401 if a detected change in range of an RFID tag 201 exceeds a predetermined threshold or if the RFID radio tag cannot be detected by the detector 301. Range may be detected, for example, by measuring the time of a returned radio signal from a tag 201, by measuring the strength of a returned radio signal from a tag, or by detecting changes in a periodic interval at which energy is transmitted by a tag.

Abstract: A navigation performance based flight path deviation display assembly includes a display and a display processor capable of generating an image upon the display. The image includes at least one flight path scale comprising a reference point bounded by end markers extending in at least one of a lateral and vertical direction. The display also includes at least one moveable deviation pointer disposed on the flight path scales. Additionally, the image includes a representation of at least one extendable navigation error disposed on the flight path scale, and extending from at least one of the end markers toward the reference point based upon an actual navigation performance (ANP) and the RNP for the aircraft. The image may also include at least one moveable intersecting flight path pointer disposed on the flight path scales.

Abstract: A vehicle speed control apparatus for allowing a host vehicle trailing a preceding vehicle to accelerate and decelerate without causing discomfort to the host vehicle driver. While the host vehicle is trailing the preceding vehicle, the apparatus on board the host vehicle stores the speed of the preceding vehicle entering a curve ahead as well as a headway distance of the host vehicle to the preceding vehicle. Upon reaching the curve, the host vehicle is controlled by the apparatus to enter the curve at a speed not in excess of the stored speed of the preceding vehicle.

Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art.

Abstract: Under a multi-path environment, the receive timing for an incoming wave of the minimum propagation delay time cannot be accurately measured in the prior art. By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation section 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timings that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, the reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time.

Abstract: In preceding vehicle following control apparatus and method for an automotive vehicle, a vehicular velocity controller includes a target inter-vehicle distance calculating section that calculates a target inter-vehicle distance from the vehicle to a preceding vehicle detected by an inter-vehicle distance sensor on the basis of a vehicular velocity detected by a vehicular velocity detector and an inter-vehicle distance detected by an inter-vehicle distance detector, a first vehicular velocity controlling section that performs a vehicular velocity control to bring the detected inter-vehicle distance substantially coincident with the target inter-vehicle distance, and a vehicular deceleration stopping section that performs a vehicular deceleration control to stop the vehicle in accordance with the inter-vehicle distance from the vehicle to the preceding vehicle immediately before a time point at which the inter-vehicle distance detector which trapped the presence of the preceding vehicle has not detected the pre

Abstract: The invention is directed towards a system and business process which provides for reconciliation and accounting services necessary to support automated vehicle identification (AVI) tag utilization irrespective of vehicle owner. A plurality of AVI's, alternatively referred to as “Toll Tags” are acquired and such tags are registered with a centralized reconciliation and accounting entity. The acquired tags are then physically affixed to a motor vehicle within a multiple vehicle entity's fleet. The invention digitally acquires and combines charges attributed to tag usage, with information relating to transient drivers utilizing the fleet's vehicles who have incurred charges during a period of vehicle utilization.

Abstract: Interrogators, wireless communication systems, methods of operating an interrogator, methods of operating a wireless communication system and methods of determining range of a remote communication device are provided. According to a first aspect, an interrogator includes communication circuitry configured to output a plurality of wireless signals toward a radio frequency identification device and to receive a plurality of wireless signals from the radio frequency identification device; and a processor coupled with the communication circuitry and configured to determine a range of the radio frequency identification device relative to the interrogator responsive to the received wireless signals.

Abstract: Frequency resources of a DME/TACAN band specified for the aircraft band are effectively utilized, and a GPS reinforcing data is overlapped onto distance information to be broadcast. A header is added to a DGPS reinforcing data, and the transmitting pulse level of a conventional ground DME system is modulated, and the data is broadcast to an airborne system. In the airborne system, a threshold value of “1” and “0” is generated by a level detecting device (5), and the start point of the data is detected by a header detecting device (6), and the reinforcing data is supplied to the airborne system. Consequently, the function of broadcasting a data by overlapping the data onto the distance information of the DME is achieved. Since the DME uses the L band, the radio interference with the existing ILS, VOR, aircraft radio transmission, and broadcasting station can be avoided.

Abstract: A golf distance indicator system provides measurement and display of the distance between a golfer and the pin on the green he is approaching. The system comprises a portable unit carried by the golfer and an target unit located on the pin. With the portable unit, the golfer selects the hole he is playing then activates the system. The portable unit sends a wireless coded message to an intended target unit. When a target unit receives a message, it analyzes the message to see if it should respond. If the target unit determines that it should respond, it sends a coded responding message to the portable unit. When the portable unit receives a responding message, it analyzes the responding message to see if the responding message originates from the intended target unit. If it does, the portable unit calculates a distance based on the elapsed time for the communications and the speed of the communications. The results are displayed on the portable unit.

Abstract: A system is described for discriminating between a transmitted signal and background noise comprising a transmitter adapted to transmit a signal including first and second pulses, separated by a predetermined time interval; and a receiver including a pulse detector to detect pulses received from the transmitter; a delay circuit adapted to delay transmission of the first pulse for a predetermined period of time in communication with the detector to receive a pulse therefrom; and an AND gate having an output, a first input in communication with the delay circuit and an second input in communication with the detector, the time of transmission between the pulses equaling the time delay of the delay circuit, whereby the AND gate allows transmission of a signal only when simultaneously receiving pulses from the detector and the delay circuit.

Abstract: A reflector is constituted by a right pseudo-dihedral, a ridge (C) of which is in the form of a portion of a helix so as to provide a calibrator or a beacon.

Abstract: The disclosure pertains to the localization of a station by another station in a network for the transmission of data in packets, each packet being formed by a header followed by an information field at a carrier frequency that varies according to a linear ramp. The method consists, in a first station, in sending out an interrogation packet with a designation of a second station, in the second station, upon the reception of this interrogation packet, in sending a signal in continuity with the field of the packet received and according to the same ramp and, in the first station, in measuring the delay of this signal, when it is received, with respect to a signal produced in the first station after the field of the packet sent out and in deducing the distance between the two stations from the delay. Application to the measurement of distances.

Abstract: A method and apparatus determines the location of a signal transmitter located at an unknown location by using externally-induced intermodulation distortion emitted from the signal transmitter. A transmitter locator emits an interrogation signal having a frequency that is offset from the frequency of the signal emanating from the signal transmitter. The interrogation signal and the carrier signal of the signal transmitter are "mixed" within the signal transmitter to form an intermodulation product signal. The intermodulation product signal having a different frequency is then radiated from the unknown signal transmitter. A receiver tuned to the frequency of the intermodulation signal detects the returned signal and a processor determines the range and direction from the transmitter locator to the location of the signal transmitter.

Abstract: A method and apparatus for encoding and decoding data on navigation signal pulse pairs utilizes pulse position modulation (PPM). The pulse interval between a first pulse and a second pulse of the pulse pair is varied depending on whether the logic value of the data to be encoded is a logic "0" or a logic "1". A tri-graph encoding process converts the raw input data into encoded input data. Each input data bit is encoded into three bits with each bit having the same logical value as the input data bit. The encoded input data is then encoded on the navigation signal using a pulse position modulation (PPM) technique. A decoder recovers the encoded data and provides an error correction process for high data integrity that corrects certain bit errors that may occur during the transmission and reception of the data on the navigation signal. The error correction process detects and corrects errors such as a missing bit, an extra bit or a bit error.

Abstract: A balanced receive antenna circuit configuration determines an accurate position of a transponder within the antenna field pattern of the reader antenna. The balanced receive antenna configuration consists of two antennas physically rotated 90 degrees relative to one another, disposed concentrically on top of one another. Furthermore, each receive antenna consists of two coils located a predetermined distance apart. The optimum distance separating the coils is determined by trading off zero position detection with the transponder detection range. A third receive reference antenna is concentrically disposed, sharing the same horizontal plane with the balanced antenna coilsets. The transmitter antenna is disposed separately from the receive antennas. In operation, initially the transmitter antenna sends a power burst signal for a predetermined duration to charge up the transponder to the maximum charge possible.

Abstract: A system and method for determining the range between a receiver of a radio frequency signal and a transmitter of the signal includes transmission of a ranging signal having a grossly timed trigger followed by a chirp waveform. In response to receipt of the leading edge of the grossly timed trigger, the receiver of the ranging signal generates a first reference chirp at about the same time as the expected time of receipt of the chirp waveform, and thereafter compares the two chirps to provide a time correction signal (it being known that when two identical chirp signals, one time delayed from the other, are mixed, the resulting signal will have a frequency proportional to the amount of delay between the two chirp signals.) The time correction signal is used to correct the timing of an outgoing corrected chirp that is to be used to determine range between the transmitter and receiver based on a time of arrival.

Abstract: A comparator circuit compares two temporally separated input bursts of signals which occur at two different frequencies. The first burst is an interrogation pulse and the second burst is a reply pulse in a DME system. The comparator circuit includes a first frequency converter (CO1) for receiving at an input thereof the two input bursts, and a comparing device (DC) connected to receive an output of the first frequency converter (CO1). In order to reduce the measurement errors, the first frequency converter (CO1) receives at the input thereof the two input bursts and converts them into two new bursts of signals that have a common frequency so that the comparing device (DC) can carry out the comparison at the common frequency.

Abstract: An interrogator-transponder system in which multiple vehicle mounted transponders which may be closely spaced in distance and moving at similar velocities are interrogated by interrogation signals that are identical for all interrogations. Digital coded data blocks consisting of an address code and a message code are transmitted on the interrogation frequency and are interleaved with the interrogation signals. Transponders respond with a coherent identification code and a message data code signal that is displaced in frequency from the interrogation signal by an amount that is identical for each transponder. The transponders decode interrogator data blocks that are associated with an address that is identical to the transponder identification code. The response signal spacings in time are difference for each transponder but are always multiples of the pulse repetition interval of the interrogation signal.

Abstract: Apparatus for visually displaying simultaneously on one screen two variables that characterize the path followed by a land, marine or airborne vessel with reference to a preselected or ideal path that extends from a beginning point to an ending point.

Abstract: An apparatus to be employed within a precision distance measuring system for estimating pulse time-of-arrival. The apparatus facilitates the use of an Adaptive Fixed Threshold method for such estimation. The invention compensates for pulse time detection errors induced by variations in incident pulse amplitude and shape by adjusting the estimated time-of-arrival. This adjustment is performed as a function of the measured pulse slope between two low-amplitude threshold levels through the use of a predetermined reference table of error adjustment times.

Abstract: A passive surveillance method and system, capable of operation in conjunction with both non synchronous and synchronous pulse pattern rotating ground radars. Received signal scan modulated pulses are deinterleaved and correlated with a previously selected repetitive portion of an interrogation signal source base pulse pattern. A single receiver channel, sequential lobe on receive only (LORO) direction finding antenna is employed in the system to modulate received signals to extract target object relative bearings for the correlated signals. The system makes use of all available data to determine the best estimate of the target object position.