摘要:
An each pattern is provided a reception pathway, the method uses the synchronous replies and the asynchronous replies, unsolicited of Fruit type, transmitted by targets present in the aerial environment of the radar and detected over a given number of antenna revolutions. At each detection of a reply the value of its off-aim in bearing and the value of relative power received on each of the pathways are calculated as is its elevation by extrapolation with the synchronous detections close to the same target and associated with the detection. The values obtained over the given number of revolutions are stored, the measured patterns being sampled on the basis of the stored values.
摘要:
A device and method for secondary radar signal reception with quasi-dynamic or dynamic sectoring of a space to be monitored. The device includes at least one antenna assembly including antenna elements for the reception of transmitted secondary radar signals, a signal processing unit connected via a connection point to the antenna elements for the joint processing of received antenna signals, outputs associated with a couple matrix in the signal processing unit and individual receivers. The couple matrix includes adjustable coefficients for sectoring of the space to be monitored and for performing a superposition of the antenna signals using a multiplicative-additive combination of the received antenna signals. In the case of dynamic sectoring of the space, each receiver receives for each receipt telegram another weighted superposition of the antenna signals with certain couple coefficients, and in the case of quasi-dynamic sectoring the adjustable coefficients are fixed over a longer time period.
摘要:
An algorithm for improved tracking of Air Traffic Control Radar Beacon System transponders is disclosed. The algorithm can be combined with a system that includes an interrogator which transmits an interrogation signal to an associated vehicle transponder at a first frequency, preferably 1030 MHZ in accordance with FAA regulations, and a receiver array which receives the transponder reply signal transmitted by the transponder at a second frequency, preferably 1090 MHZ in accordance with FAA regulations. An angle of arrival processor calculates an angle of the received reply signal, and a position processor calculates the vehicle position based on at least the received angle data.
摘要:
A beam sharpened antenna pattern is achieved by intercoupling signals from individual radiating elements of an array to produce a sum mode signal and a ring mode signal. The ring mode signal represents a forward-directed antenna pattern having a zero to 360 degree progressive phase characteristic around a pattern axis. Beam sharpening results from processing the sum and ring mode signals to provide a pattern having 360 degree beam sharpening, which represents portions of the sum mode pattern of amplitude greater than the amplitudes of selected portions of the ring mode signal. The ring mode signal may be provided on a predetermined basis after selected attenuation or amplification in order to provide a beam sharpened antenna pattern having a modified characteristic. In some applications, received signals are processed on a simultaneous sum mode and ring mode basis, while during transmission pulsed sum mode and ring mode antenna patterns are activated on a sequential, timed basis. Arrangements for use of the invention with two-dimensional-scan and one-dimensional-scan phased arrays are also described.
摘要:
A radio environment measuring system for measuring a propagation state of radio waves includes: a fixed radio apparatus provided in a base station; a mobile radio apparatus operatively connected to the fixed radio apparatus through the radio waves; the mobile radio apparatus having a repeater unit for receiving a transmission signal from the fixed radio apparatus and sending a returned signal to the fixed radio apparatus; and the fixed radio apparatus having a transmission/reception unit for sending the transmission signal to the mobile radio apparatus and receiving the returned signal from the mobile radio apparatus, and a measuring unit for measuring the propagation state of the radio waves, for example, a propagation distance, direction and reception intensity of the radio waves between the fixed radio apparatus and the mobile radio apparatus based on the transmission signal and the returned signal.
摘要:
Identification system constituted by an interrogation station or interrogator 1 itself formed by a radio frequency wave transceiver and preferably on an ultra frequency wave length 5, and, on the other hand, by a responder unit 2 adapted to receive the wave and to re-emit (echo) it following the given coded modulation to the responder unit. The interrogator is adapted to receive this echoing wave 11 and to demodulate it in order to derive the identification code therefrom. The interrogator has an emission antenna adapted to emit an inquiry signal constituted by a radio wave emitted in plane polarization. The responder unit has two adjacent antennas, respectively, for the reception of the inquiry wave and for its re-emission (echo) after modulation. The two antennas are of the circular polarization type and each functioning in a direction of rotation of the polarization opposite with respect to each other. This allows a differentiation between the emission inquiry signal and the response signal, since the inquiry signal wave is received by a circular polarization-type antenna of the responder unit according to a first rotation direction of the polarization. The responder unit is adapted to re-emit a modulated response signal constituted by a radio wave of the same kind as the inquiry wave of circular polarization-type according to a second rotation direction of the polarization in the opposite direction to the first rotation direction.
摘要:
A secondary surveillance radar system in which monopulse processing is used to obtain angle estimation of azimuth bearing, the improvement residing in a precision method, involving a monopulse qualifier signal, for identifying the maximum unambiguous off-boresight azimuth (OBA), while ensuring reduced sensitivity to Omni channel variations; the monopulse qualifier signal is developed from coherently combining the IF limited signals derived from the Sum+JDelta and Delta+jSum signals, such that two amplitude varying signals are created, such signals bearing a direct relationship to the Sum and Difference antenna pattern ratios and being independent of antenna signal power.
摘要:
Located adjacent to runways, taxiways, and approach ramps are secondary radar interrogators which radiate the P1 and P3 pulses and the P2 pulse via different directional patterns into sectors to be monitored which are individually assigned to each interrogator. Direction finders at different locations determine the directions of arrival of SSR reply signals radiated by an airborne SSR transponder in a sector to be monitored. From the directions of arrival and the locations of the direction finders, the respective transponder position is determined. The interrogators require no central control. Alternatively, the arrival times of the SSR reply signals are measured at several points; an evaluating device forms the differences in arrival time, and the intersection of the hyperbolic lines of position determined in the evaluating device is the position of the transponder.
摘要:
A circuit is provided for generating error signals from a tracking radar le system. The error signals represent normal tracking error and error due to side lobe tracking. An amplifier is connected to the generating circuit for producing a first tone, indicative of normal error and a different second tone due to side lobe tracking error.
摘要:
An inquiry-reply system utilizing a primary inquiry antenna which has a distinctive main lobe radiation pattern and less distinctive and smaller side lobes. An additional antenna is provided which has directional sensitivity arranged to be weakest in the area of the main lobe of the primary inquiry antenna and to be at a maximum in the vicinity of the side lobes of the antenna. False information is radiated by the additional antenna to disguise the inquiry code in the regions of the side lobes.