Thales

Patrick Le Bihan

Pascal Cornic

Stéphane Kemkemian

Patrick Garrec

Yves Audic

Myriam Nouvel-Fiani

Jean-Michel Quellec

Philippe Lacomme

Myriam Patricia Nouvel

Stépahne Kemkemian

Joël Fillatre

Régis Levaufre

A method comprises at least: a first radar processing for locating and estimating the trajectory of a target on the basis of measurements of radial distances, of Doppler frequency and of angle of azimuth and of elevation of the target arising from a radar signal emitted towards the target; a second radar processing of location and of trajectory of the target along a vertical axis, by applying the principle of the inverse synthetic antenna; the disparity between the given trajectory and the trajectory estimated by the first processing, projected on a horizontal plane, and the disparity between the given trajectory and the trajectory estimated by the second processing according to the vertical axis being used to control the direction of displacement of the target.

Method of guidance of an aerial target, in particular in the vertical landing phase, and radar system implementing such a method

A radar attached laterally to airplane fuselage to detect obstacles on a collision course with a portion of the airplane facing the radar. The radar includes an emission antennal channel and reception antennal channels in the same plane. The radar Establishing in a radar coordinate system a first distance/Doppler map allowing echoes to be separated into distance and Doppler resolution cells in reception antennal channels; Establishing a second distance/Doppler map of smaller size by selecting a subset of distance/Doppler resolution cells corresponding to possible positions of targets liable to collide with the airplane; Establishing new distance/Doppler maps by forming beams computationally from the subsets of distance resolution cells; and Temporal integration, in each beam, of successive distance/Doppler maps.

Anticollision radar, especially for an aircraft when taxiing, and anticollision system

A detection method implementing an FMCW waveform is provided, the emitted waveform is formed of a recurring pattern of given period Tr covering an emission frequency band of given width B, each pattern being divided into a given number P of sub-patterns of duration Tr/P covering an excursion frequency band &#x394;F=B/P, the sub-patterns being mutually spaced by a frequency interval equal to &#x394;F. The radar performs: a first distance-compression processing operation carrying out a low-resolution distance compression at the scale of each recurring pattern on a fraction B/P of the emission band of width B corresponding to the frequency band covered by each of the sub-patterns; a Doppler processing operation on a given number N of successive recurrences so as to form P ambiguous distance-Doppler maps of low distance resolution, the maps being segmented into various speed domains; a second distance-compression processing operation of resolution that differs depending on the speed domain to which the relative speed of the target with respect to the radar belongs.

Multi-resolution FMCW radar detection method and radar implementing such a method

A digital receiver comprising at least two reception pathways, the method carries out a digital inter-correlation of the signals obtained as output from at least two filters of different central frequencies and different ranks, the rank and the central frequency of the filters being chosen as a function of a determined frequency-wise search domain. For a determined search domain, the various sampling frequencies of the reception pathways are chosen so that the ambiguous frequencies resulting from the spectral aliasings vary as a monotonic function of the true frequency of the signals.

Method for detecting signals in a frequency-ambiguous digital receiver, and digital receiver implementing such a method

An active and passive detection device is provided with a low probability of interception having a fixed antenna structure, transmission means and reception means. The antenna structure is formed by a plurality of radiating elements grouped into identical subnetworks and comprises at least one transmission subnetwork and at least three reception subnetworks. The transmission means are capable of generating an unfocused continuous waveform having low peak power in one plane and of transmitting said waveform. The reception means are capable of detecting the targets following the formation of a plurality of directional beams on the basis of the signals received on the reception subnetworks. The reception means are likewise capable of implementing the interception of radar signals from other radar sources using cross correlation processing between the signals received on at least three reception subnetworks.

Active and passive electromagnetic detection with a low probability of interception

A radar includes a transmitting antenna and receiving antenna formed by an array of radiant elements. Antenna beams are calculated in P directions by a BFC function. Detections of a target by secondary lobes of the beams are processed by an algorithm comparing levels received in a distance-speed resolution cell, a single detection at most not being possible for each distance-speed resolution cell. Processing means use the assumption that there may probably be more than one echo with a signal-to-noise ratio that is sufficient to be detectable, for a given resolution cell of the radar, either in speed mode or in distance mode, or, alternatively, a distance-speed depending on the processing implemented; and, if there is more than one echo detectable for each resolution cell out of the plurality of beams formed by BFC, only the echo and BFC that obtain maximum power or maximum signal-to-noise ratio are/is considered valid.

Radar with wide angular coverage, notably for the obstacle avoidance function on board auto-piloted aircraft

A method includes: generating a frequency-modulated continuous signal, an emission sequence being formed of successive ramps centered on a carrier frequency; fixing a modulation band &#x394;F and the duration Tr of a recurrence in such a way that at the range limit, a reception ramp appears shifted by at least one given frequency with respect to the corresponding emission ramp, on account of the propagation delay for the outward-return journey to a target kTr+&#x3b8;, k being an integer and &#x3b8; a duration less than Tr; demodulating the signal received by the signal emitted, the resulting signal including a first sinusoid at the frequency &#x3b4;Fdim=(1&#x2212;(&#x3b8;/Tr)&#xb7;&#x394;F and a second sinusoid at the frequency &#x3b4;Fd=(&#x3b8;/Tr)&#xb7;&#x394;F; sampling the resulting signal and performing a first fast Fourier transformation on this resulting signal over the duration of each emission ramp; detecting in the resulting spectrum the spectral lines appearing at the frequencies &#x3b4;Fd and &#x3b4;Fdim, and performing the vector sum of these two spectral lines after resetting them into phase with respect to one another; and performing a detection by comparing the modulus of the vector sum with a predetermined threshold.

Radar detection method, notably for airborne radars implementing an obstacle detection and avoidance function

The present invention relates to a radar device with high angular accuracy. The solution provided by the invention simultaneously combines an interferometer that is accurate but, for example, ambiguous when receiving; and a space coloring mode when transmitting. The coloring of the space consists notably in transmitting on N transmitting antennas N orthogonal signals. These signals are then separated by filtering on reception using the orthogonality properties of the transmission signals. It is, for example, possible, with two contiguous antennas in transmission associated with two orthogonal codes to produce a single-pulse type system when transmitting. The invention applies notably to the obstacle sensing and avoidance function, also called 'Sense & Avoid'.

Radar with high angular accuracy, notably for the obstacle sensing and avoidance function

A radar device includes an antenna having at least two linear arrays of radiating elements being orthogonal to one another, a first array being used to focus a transmission beam in a first plane and a second beam being used to focus a reception beam in a second plane, orthogonal to the first plane. The focussing of the beam is obtained in the first plane by colored emission followed by a reception beam formation by computation, and in that the focussing of the beam is obtained in the second plane using reception beam formation by computation. The colored emission is carried out by combining antenna transmission sub-arrays in such a manner as to form a sum channel and a difference on reception channel according to the monopulse technique.

Agile-beam radar notably for the obstacle 'sense and avoid' function

An airborne radar device having a given angular coverage in elevation and in azimuth includes a transmit system, a receive system and processing means for carrying out target detection and location measurements. The transmit system includes: a transmit antenna made up of at least a first linear array of radiating elements focusing a transmit beam, said arrays being approximately parallel to one another; at least one waveform generator; means for amplifying the transmit signals produced by the waveform generator or generators; and means for controlling the transmit signals produced by the waveform generator or generators, said control means feeding each radiating element with a transmit signal. The radiating elements being controlled for simultaneously carrying out electronic scanning of the transmit beam in elevation and for colored transmission in elevation.

Airborne radar having a wide angular coverage, notably for the sense-and-avoid function

The present invention relates to system for detecting obstacles () on the ground () onboard a carrier (). The detection system comprises at least two continuous-wave radars (). The radars () are linked to a system () for utilizing the detection data arising from the radars (). The detection system performs localization of an obstacle (): along a radial axis () between a radar () and the obstacle (), by calculating the distance between the radar () and the obstacle (); along a vertical axis () with respect to a radar (), by calculating the elevation of the obstacle () using monopulse deviation-measurement processing. The detection system performs localization of an obstacles along a horizontal axis () transverse with respect to a sighting axis () of a radar (), by calculating the azimuthal position of the obstacle (). The invention applies notably in respect of the detection of obstacles on the ground so as to avoid any collision between a taxiing aircraft and these obstacles.

Growing community of inventors

Lannilis, France

Patrick Le Bihan