Abstract: Embodiments of the present invention provide RFID systems having a centralized frequency source and controller. The centralized frequency source generates a reference signal, having a frequency below the RF band of interest, which is transmitted to a plurality of reader nodes. The centralized controller generates and transmits data to the plurality of reader nodes. At each reader node, the reference signal is converted to an RF carrier signal that is modulated and transmitted within corresponding read field of the reader node. This modulated RF carrier signal may interrogate and communicate with one or more RFID tags within this read field. The RF carrier signal may also be held constant to enable communication from RFID tags to the reader node, which is subsequently transmitted back to the centralized controller or processor.

Abstract: A method and apparatus for validating a distance output of a phase ranging RFID location system, based upon the phase readings included in data sets obtained from monitoring reply signals corresponding to interrogation signals at multiple frequencies and a common interrogation signal beam direction; by comparison of measured phase and frequency data sets with theoretical phases calculated with respect to the same frequencies over a range of positions corresponding to a beam extent of the interrogation signal. The distance output validated by comparison with theoretical threshold data processed to generate an extreme values distribution from which a cumulative distribution function is extracted and against which a confidence level is applied.

Abstract: A method of measuring a range from a reader unit to a non-contacted IC medium, includes: transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium; causing the non-contacted IC medium to perform modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency, and causing the non-contacted IC medium to respond to a response signal at the modulated frequency; causing the reader unit to receive the response signal to acquire a plurality of frequency components; calculating a phase difference between signals of at least two of the acquired plurality of frequency components; and measuring the range by using the phase difference.

Abstract: In certain embodiments, a method includes receiving first track information comprising data for a particular aircraft track. The method further includes receiving a first radar plot comprising first location information corresponding to first aircraft identification information and first location information corresponding to second aircraft identification information. The method further includes associating the first aircraft identification information with the particular aircraft track. The method further includes accessing historical association information comprising a first association history variable corresponding to one or more previous associations between the first aircraft identification information and the particular aircraft track and a second association history variable corresponding to one or more previous associations between the second aircraft identification information and the particular aircraft track.

Abstract: The invention provides a system and method for reducing the instance of friendly fire by having the weapon aiming system include means for emitting an optical signal encoded with the identity of the targeting soldier. The encoded optical signal is received by an optical receiver on a targeted soldier where it is converted into a low power RF signal which is transmitted to a local repeater that retransmits it, optionally using at least one intermediate repeater, to a central monitoring station equipped with a computerized database. If the monitoring station determines that the doubly encoded signal includes the identities of two friendly troops, it transmits a “hold fire” signal back to the aiming system, and a suitable signal, such as a red LED indicative of a “hold fire” order is illuminated.

Abstract: Systems and methods are delineated that may provide for a system for use in a merging and spacing application for an aircraft. An exemplary system may comprise a TCAS and a processor for executing the merging and spacing application using ADS-B data and data received by the aircraft in response to an interrogation of another aircraft from the TCAS. In a disclosed embodiment, a lead aircraft responds to the TCAS interrogation from a following aircraft to provide EHS heading and/or speed of the lead aircraft to the following aircraft, which uses the received EHS data as well as ADS-B data to determine merging and spacing control parameters for the following aircraft.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: An antenna outputs query signals to a wireless tag, and receives response signals output from the wireless tag. An intensity detection circuit detects the signal intensity of the response signals. A control portion judges the type of toner housed in a cartridge, or whether the toner is a certified product or a non-certified product, from the detected signal intensity. Further, the control portion outputs to an output setting circuit an instruction signal to change the signal intensity of the query signals, such that normal wireless communication can be performed with the wireless tag.

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: Techniques are described that allow information to be acquired by an ADS-B system of an aircraft without the installation of ADS-B dedicated flight crew controls or wired data interfaces in the aircraft. In one or more implementations, a receiver is associated with the ADS-B system in the aircraft. The receiver is configured to receive transmissions from a transponder of the aircraft, such as a radar transponder of a Traffic Collision Avoidance System (TCAS), or the like. Information used by the ADS-B system is extracted from the received transmissions and furnished to the ADS-B transceiver for broadcast over the ADS-B datalink.

Abstract: A transmitter provides a plurality of output signals. The transmitter includes a processor, a modulator, a first circuit, and a second circuit. The modulator provides a modulated signal responsive to the processor. The modulated signal includes an amplitude modulated radio frequency for transmitting a pulse. The first circuit provides a first output signal, responsive to and with higher power than the modulated signal. The first output signal has a first phase during transmitting of the pulse. The second circuit provides a second output signal, responsive to and with higher power than the modulated signal. The second output signal has a second phase during transmitting of the pulse. The second phase is controlled by the second circuit in accordance with the first phase, the second phase, and indicia of a third phase provided by the processor.

Abstract: An emergency locator beacon testing and communication system is described. The system uses privately-owned Local User Terminals which provide direct feeds to a privately-operated beacon information processor having dedicated on-line servers for consolidating and providing access to beacon test information. The system receives beacon signals relayed through the Cospas-Sarsat satellite system, correlates the beacons' unique identification numbers (UIN's) in the received signals to the UIN's of beacons known to be undergoing testing, collects the data transmitted by beacons under test, and displays beacon test results in a useful format on a user-friendly website.

Abstract: The present invention comprising: a first local oscillator for generating a first frequency; a second local oscillator for generating a second frequency; phase-difference setting means for setting a first phase difference between a transmission signal and an output of the aforementioned first local oscillator; phase-difference detection means for detecting a second phase difference which is the phase difference between a reception signal and an output of the aforementioned second local oscillator, and calculation means for calculating a distance to a communication counterpart from a third phase difference and a fourth phase difference which are notified by the communication counterpart, and from the aforementioned first phase difference and second phase difference, wherein the third phase difference is set to the second frequency by the communication counterpart, and the fourth phase difference is set to the first frequency by the communication counterpart.

Abstract: Integration of ionospheric models in over the horizon radars (OTHR) is achieved with very little or substantially no change to existing coordinate registration systems or software by specifying a virtual transponder at a target location and generating a signal which appears to have emanated from a transponder at that location. A return path to said virtual transponder is ray-traced through the ionospheric model to produce propagation parameters; and an appropriately delayed virtual transponder signal is inserted into the receiver. The result produced at the receiver is used to perform coordinate registration for further received signals.

Abstract: Systems, apparatuses, and methods estimate the distance between a player and a ball by transmitting a chirp (sweep signal) to a radio tag located on the ball. During the chirp, the frequency of the transmitted signal is changed in a predetermined fashion. The radio tag doubles the transmitted frequency and returns the processed signal to a transceiver typically located on the player. The currently transmitted frequency is then compared with the received frequency to obtain a difference frequency from which an apparatus may estimate the distance. The apparatus may simultaneously receive the processed signal from the radio tag while transmitting the sweep signal.

Abstract: A pulse detecting equipment includes a log compression processor (105) for logarithm-converting signal levels of a reception signal received at an antenna and input therefrom, with maintained frequency components of the reception signal as input, an AD converter (106) for converting the reception signal as logarithm-converted in signal level, from an analog form into a digital form, a first detector (110) for limiting the reception signal as converted into the digital form to a band of a prescribed first frequency, to obtain a signal, to detect signal levels thereof, a second detector (111) for limiting the reception signal as converted into the digital form to a band of a prescribed second frequency smaller than the first frequency, to obtain a signal, to detect signal levels thereof, and a pulse detector (113) for use of a result of comparison between signal levels detected at the first detector and signal levels detected at the second detector, to detect pulses of a prescribed frequency as a signal transmi

Abstract: A system and method for communication that could be used in an identification friend or foe system. The method comprises generating a first message by a processor and controlling a beam steerer to deflect transmitted waves toward a first angle. The method further comprises transmitting the first message through an antenna in communication with the beam steerer toward the spatial angle. The method further comprises controlling the beam steerer to deflect waves received from the spatial angle. The method further comprises receiving a responsive wave at the antenna through the beam steerer at the spatial angle, the responsive wave including a second message responsive to the first message.

Abstract: When an excitation signal is generated from an exciter due to an activation signal generated from a radar control device and is distributed to supply to each antenna sub-module, a combination reception signal is transmitted to a receiver from each antenna sub-module. The receiver takes in the combination reception signal obtained by each sub-module in response to an instruction from the radar control device, a frequency converter converts the combination reception signal into a prescribed frequency band, and a distributed aperture combination circuit performs a beam combination in accordance with a distributed aperture combination algorithm. In this way, a radar apparatus, which is equivalent to an active phased array radar of a large aperture and with high performance, is achieved.

Abstract: A system is delineated comprising a TCAS receiver having one or more filters, one or more amplifiers and one or more A/D converters, the one or more A/D converters for digitizing analog data into digital data for decoding one or more of an ADS-B message and a TIS-B message; and circuitry for receiving the digital data and decoding the one or more of an ADS-B message and a TIS-B message, wherein the circuitry includes two or more paths for the decoding.

Abstract: Ground vehicle reporting and tracking techniques are provided to track vehicles associated with a particular area (e.g., an airport, a military base, etc.). Ground vehicles may regularly report information about the vehicle to one or more control stations via corresponding communication links. The communication links may include, for example, an Automatic Dependent Surveillance-Broadcast (ADS-B) link and a non-ADS-B link.

Abstract: A method for determining the presence of a transmitter and a receiver in a vehicle by means of a central processing unit, wherein said transmitter and receiver are designed for transmitting electromagnetic or optical signals in a predetermined direction and for receiving said signals from substantially the same predetermined direction, respectively, for example for communicating between different vehicles, and wherein said transmitter and receiver are operatively connected to the central processing unit, comprising the steps of: generation of a signal in the central processing unit; transmission of a signal by the transmitter in dependence on the signal generated in the central processing unit; reception by the receiver of the signal from the transmitter; and determination by the central processing unit of the presence of the transmitter and the receiver in dependence on the signal from the receiver.

Abstract: An apparatus for measuring the relative direction of an incoming radio signal, the apparatus comprising at least first and second antennas, and comparison means for comparing the incoming radio signal as received at the first antenna with the incoming radio signal as received at the second antenna, and from the result of the comparison transmitting a measurement of the relative direction.

Abstract: An active radar target comprising a plurality of receive antennas and a plurality of transmit antennas arrangeable into pairs of antennas with at least one antenna in a pair being at a different height to at least one antenna in a different pair of antennas.

Abstract: A method and system for monitoring one or more objects by an electronic device are provided. The method includes defining a distance threshold between the electronic device and an object having a RFID tag, calculating a distance between the electronic device and the object, and generating alerts upon detecting that the distance is greater than the distance threshold.

Abstract: Systems and methods that coordinate assignments of aircraft operating within a controlled airspace to ground radios are provided. In one embodiment, such a system includes an air traffic control (ATC) facility (12), a plurality of ground radios (16A-16C), and a network manager (20) communicatively coupled to the air traffic control facility (12) and the ground radios (16A-16C). The air traffic control facility is responsible for controlling aircraft (14A-14I) operating within the airspace (10) and providing ATC information to the network manager (20). The ground radios (16A-16C) are operable to provide communications between the air traffic control facility (12) and the aircraft (14A-14I). The network manager (20) is operable to assign each aircraft (14A-14I) to one of the ground radios (16A-16C) based on network management considerations using the ATC information.

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 transponder-based beacon transmitter system in an unmanned aerial vehicle is provided. The transponder-based beacon transmitter system comprises a global positioning system interface communicatively coupled to receive position information indicative of a current location of the unmanned aerial vehicle, a message formatter communicatively coupled to the global positioning system interface, and a transponder-based beacon transmitter. The message formatter formats vehicle identification of the unmanned aerial vehicle and the position information indicative of the current location of the unmanned aerial vehicle into an automatic dependent surveillance broadcast mode-select squitter message. The message formatter operates in one of a military mode, a National Airspace System mode, and a combined military/National Airspace System mode. The transponder-based beacon transmitter transmits the automatic dependent surveillance broadcast mode-select squitter messages from the unmanned aerial vehicle.

Abstract: To provide a wireless IC tag which is readable even in a plurality of countries (destination countries) using different radio frequency bands for reading. The wireless IC tag of the present invention is characterized by comprising: a case (20); an antenna (60), which is provided in the case (20); a metal plate (901), which is disposed in the case opposite to the antenna (60); and a mechanism for altering the resonance characteristics of the wireless IC tag (10) by moving at least one of the antenna (60) and the metal plate (901) in the case (20), thereby altering the distance (D) between the metal plate (901) and the antenna (60). With such wireless IC tag (10), the capacitance of an equivalent tuning capacitor consisting of the antenna (60) and the metal plate (901) can be arbitrarily altered by a distance alteration unit, and thereby, the resonance characteristics of the wireless IC tag (10) can be altered in accordance with the frequency band of reading radio wave used by a reader/writer.

Abstract: A system according to the invention detects location information of a vehicle by using a reflection strength change of an electromagnetic wave. The system incorporates a radiowave transmitter which emits a first radiowave, positional markers which generate unique reflection strengths and patterns of temporal changes in the reflection strength from the emitted first radiowave at respective absolute positions, a radiowave receiver which receives a second radiowave reflected by the positional marker and converts the second radiowave into a signal format for extracting location information to output the same, and a marker recognition device which obtains a location of the vehicle from the output of the radiowave receiver. Accordingly, a highly-precise location specification with a resolution smaller than or equal to 1 cm and a highly-reliable location specification which is not affected by slip and slide of the vehicle's wheels can be realized.

Abstract: A method is provided for mobile device enabled radar tags. A signal is transmitted to a radar tag. The radar tag detects the signal. The radar tag provides information. The information is received from the radar tag. A location of the radar tag is determined based on the information. The radar tag is identified based on the information. The identification of the radar tag, the location of the radar tag, and a time associated with determining the location of the radar tag are recorded as data in a database. The radar tag is evaluated based on accessing a plurality of recordings of the data in the database.

Abstract: The invention relates to a method for increasing the accuracy of a measurement of a radio-based locating system comprising a mobile station and at least one fixed station, wherein the movement of a mobile station from an initial position is detected by way of measuring data of an absolute sensor system and a relative sensor system, a virtual antenna is embodied in the form of synthetic aperture by way of measuring data and the mobile station is focused on the fixed station and/or vice versa by using the synthetic aperture.

Abstract: Systems and methods for monitoring and classifying RF emissions in the field include storing an electronic signature map (ESM) of a selected geographic area, where the electronic signature map includes previously detected emitter closeness measures (ECMs) in the selected geographic area. The ECMs are representative of detected sources of radio frequency energy. A RF energy emission is detected, a new ECM for that RF energy emission is created, and that the new ECM is compared with the ECMs in the ESM. That comparison may help to determine whether the RF energy emission should be considered a threat.

Abstract: Wheel Electronics and Tire Control System for Measuring a Measurand is provided. The wheel electronics may include a receiving device for picking up and digitizing an amplitude-modulated request signal, which has a carrier frequency for encoding a request, having a first evaluation device, which checks the request signal for the presence of a request contained therein, and having a digital counter for generating an envelope of the request signal, which has a counter input for coupling the request signal, which is clocked at a clock signal frequency different from the carrier frequency and is determined from the clock signal frequency and the request signal of its envelope. Furthermore, the invention relates to a tire control system for measuring a measurand with this type of wheel electronics.

Abstract: RFID tags, tag circuits, and methods are provided that reduce at least in part the distortion to received wireless signals, which is caused by interference in the environment. Two or more thresholds are used to digitize the received signal implemented by two or more demodulators. Multiple low pass and digital filters may be implemented with the demodulators, allowing removal of narrow pulses caused by the interference and reduction of beat tone amplitude.

Abstract: An aircraft system includes a transponder and a processor. The processor is configured to determine if the aircraft is positioned in a predetermined restricted flying zone. If the aircraft is positioned in a predetermined restricted flying zone, the processor determines if the transponder is functioning in a transmit mode. If the transponder is not functioning in a transmit mode, the processor sets the transponder to function in a transmit mode.

Abstract: Systems and methods for reducing radar target processing. The systems include a processor configured to receive a first input from a cooperative surveillance source and a second input from a radar device. The first input includes cooperative target information, the second input includes cooperative and non-cooperative target information, and the processor is configured to process the first and second inputs to remove cooperative target information from the second input based on the first input to generate a modified radar output for use by an output device. The methods include receiving a first input including cooperative target information from a cooperative surveillance source, receiving a second input including cooperative and non-cooperative target information from a radar device, processing the first and second inputs to remove cooperative target information from the second input based on the first input, and generating a modified radar output based on the processed first and second inputs.

Abstract: In accordance with one or more embodiments of the present disclosure, systems and methods disclosed herein provide for tracking of objects, aircraft, vehicles, and ground equipment in a tracking area, such as an airspace and/or an airport terminal area. One embodiment of a tracking system of the present disclosure comprises a signal monitoring component adapted to communicate with an object, such as an aircraft, when the object enters the tracking area. The signal monitoring component is adapted to transmit a monopulse beacon query signal to the object and receive a monopulse beacon response signal from the object. The tracking system further comprises an interface component adapted to process the received monopulse beacon response signal from the object, initialize a beacon transponder on the object, and assign a network address to the object.

Abstract: There is provided a tire state monitoring apparatus including transponders mounted on a plurality of tires possessed by a vehicle, and ECUs provided on a vehicle body repeatedly transmit address electric waves for acquiring data showing tire states to the transponders at fixed intervals. The ECUs transmit estimates of the transmission timing of the address electric waves at the predetermined transmission cycle so that the transponders can transmit the address electric waves within a communicable range, maintain the predetermined transmission cycle if the estimated transmission timing satisfies a predetermined condition, and adjust the predetermined transmission cycle if the transmission timing does not satisfy the predetermined condition.

Abstract: A wireless distance measurement system and a wireless distance measurement method that measure the distance between a base station and a terminal without clock synchronization between a plurality of base stations, and without requiring input of the position relationships between a plurality of base stations. Clock phase shift section (210) shifts a clock that is used to generate transmission pulses is phase-shifted by a specific amount every 100 nanoseconds, and A/D conversion section (211) converts a signal re-radiated from terminal (103) to a digital signal using the shifted clock. Correlation calculation section (212) performs correlation calculation between the digital signal and the transmission pulse and creates a delay profile by adding digital signals in the shifted phases between same phases, and incoming wave detection section (213) detects peaks of the pulses in the delay profile.

Abstract: In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.

Abstract: A method and apparatus for reducing transponder responses to reflected signals utilizes data in an interrogator message to confirm that if two interrogations are received within a predetermined period of time and if the two interrogator signals correspond to a side lobe followed by a reflected main beam signal, the presence of multipath reflection can be correctly identified and the reply to the main beam interrogation can be suppressed.

Abstract: Provided is a secondary surveillance radar with an improved capability of eliminating an unnecessary Mode A/C target report, which includes a transmission unit transmitting interrogations, a reception unit receiving replies, from a transponder, corresponding respectively to the interrogations, and a signal processing unit generating a Mode S target report and a Mode A/C target report from the replies. The radar also includes a combiner generating a Mode S track and a Mode A/C track respectively from the Mode S and the Mode A/C reports, and then judging whether the Mode S report and the Mode A/C report are of the same target on the basis of the Mode S and the Mode A/C tracks. When the Mode S and the Mode A/C reports are of the same target, the combiner rejects the Mode A/C report.

Abstract: An identification system which may be employed in a transport or monitoring system has at least one stationary and at least one mobile transmission unit which are each provided with an antenna, which antennas in turn are coupled inductively or capacitively to each other during the transmission of data. At least one of the antennas is designed such that in response to a mutual displacement of the coupled antennas a direction-dependent modulation of the transmitted signals occurs which is demodulated and evaluated in at least one of the transmission units, for example, by a demodulation unit and a processor, optionally a signal processor, in order to obtain information relating to the relative motion of the two transmission units. In addition to known identification functions, the identification system may perform additional important functions without requiring any significant additional expense.

Abstract: A communication system including: (a) a plurality of interrogators; and (b) at least one transponder operable, upon reception of an interrogating wave transmitted from each of the interrogators, to respond to the interrogator with a reflected wave which is generated by modulating the interrogating wave. Each of the interrogators is operable to communicate with the other of the interrogators in a wireless manner. A frequency band of the reflected wave transmitted from the transponder to each of the interrogators is preferably separated from a frequency band of a communication wave transmitted from the interrogator to the other of the interrogators, and is preferably closer to a frequency of the interrogating wave transmitted from the interrogator to the transponder, than the frequency band of the communication wave.

Abstract: The active transponder includes an input amplifier (26) arranged between an envelope detector (8) and a demodulation circuit (28). It further includes an activation unit (30) for the input amplifier and also for the demodulation circuit, which is formed by a frequency changer or mixer circuit (32), which decreases a significant modulation frequency of the modulated signal received by the antenna to a low frequency, the resulting low frequency signal then being amplified and filtered by low frequency elements. The activation unit thus consumes little electric power and sends a wake up signal to the elements operating at a high frequency when it detects said significant modulation frequency, in a very selective manner.

Abstract: An interrogator that is to be incorporated in a communication system in which each of at least one transponder is operable, upon reception of a main carrier wave transmitted from the interrogator, to respond to the interrogator with a reflected wave that is generated by modulating the main carrier wave.

Abstract: A radar target identification apparatus utilizing a pseudo-random digital code to modulate a target's return signal to include a two-dimensional range and cross range Doppler-coded return with a target's skin return and thereby identify friendly targets to the interrogating radar unit.

Abstract: Systems and methods for mapping a surface of a celestial body containing objects and terrain are provided. One system includes a Synthetic Aperture RADAR (SAR) module configured to capture a high-resolution image of the terrain of at least a portion of the surface and a map module configured to store map data representing the portion of the surface. The system also includes a fusion module configured to combine the high-resolution image and the map data to generate a high-resolution map of the portion of the surface. A method includes orbiting the celestial body, capturing, via the SAR module, a high-resolution image during each orbit, and fusing the captured high-resolution image with a low-resolution map of the surface to generate a high-resolution map of the surface. A computer-readable medium for storing instructions that cause a processor to perform the above method is also provided.

Abstract: When multiple readers for RF transponders have to be placed in close proximity, such as in adjacent lanes of a highway toll barrier, they can be set to operate at different frequencies. When signals from two adjacent ones of the readers interfere, the resulting signal includes interference terms whose frequencies equal the sum of the reader frequencies and the difference between the reader frequencies. To remove such interference terms while passing the desired terms, a tag includes a low-pass or other frequency-selective filter.

Abstract: In an object recognition apparatus for a vehicle which uses intensities of reflected waves from reflecting objects to make a recognition on whether a reflecting object is a vehicle or a non-vehicle, a plurality of transmission waves are emitted to receive a plurality of reflected waves from the reflecting objects, and a decision is made as to whether or not the reflecting object producing the plurality of reflected waves is a unitary reflecting object. If the decision shows a unitary reflecting object, the highest intensity of intensities of the reflected waves from the unitary reflecting object is compared with a reference intensity to makes a decision on whether the reflecting object is a vehicle or a non-vehicle. This enables univocally making a decision for each unitary reflecting object as to whether the reflecting object is more likely to be a vehicle or to be a non-vehicle, thus improving the recognition accuracy.