Method for optimizing the pointing of an antenna of an airborne radar system

    公开(公告)号:US11474229B2

    公开(公告)日:2022-10-18

    申请号:US16673802

    申请日:2019-11-04

    Applicant: THALES

    Inventor: Rodolphe Cottron

    Abstract: A method for optimizing the elevational pointing of an antenna of an airborne radar system at an altitude h includes an antenna and processing and calculation means, the method comprising: a. selecting an area of interest b. calculating atmospheric losses Lref at a reference altitude href at the reference range Dref and calculating a reference criterion Kref=−40 log10 (Dref); c. for each possible elevational pointing distance of the antenna Dpt from the area of interest, calculating the antenna elevation S that makes it possible to target the distance Dpt via the centre of the antenna; d. for each distance D from the region of interest, calculating the angle θ at which the antenna observes the point of the ground at the distance D and calculating a criterion; 1. K(D)=Ge(θ)+Gr(θ)−40 log10 D+Lref(href,Dref)−Latmo(h,D) 2. where Ge(θ),Gr(θ) are respectively the gains of the antenna that are normalized at emission and at reception; e. calculating all of the distances D that, for this pointing distance Dpt, satisfy the relationship K(D)>Kref so as to obtain the start and the end of the sub-swath actually able to be used by the radar system; and calculating the actually usable sub-swaths that are to be juxtaposed (A, B, C) in order to cover the whole of the area of interest without discontinuities.

    Method and system for neutralizing the effect of vibrations in a rotary-wing aircraft for airborne doppler radar

    公开(公告)号:US11320531B2

    公开(公告)日:2022-05-03

    申请号:US16716184

    申请日:2019-12-16

    Applicant: THALES

    Abstract: A method for active neutralization of the effect of the vibrations of a rotary-wing aircraft for a monostatic Doppler radar includes a first step of measuring and temporally extrapolating the vibration modes at the transmitting-receiving radar antenna, using a 3-axis vibration sensor, fixed to the antenna and near the phase centre of the antenna; then a second step of estimating the expected movements of the transmitting-receiving antenna or of the first transmitting antenna and the second receiving antenna; then a third step of compensating the expected movements of the transmission radar antenna in the transmission chain or in the reception chain of the radar transmitter, wherein the projection of the movement vector of the phase centre O on an aiming direction is calculated to determine the value of the compensation phase shift to be applied.

    Method for creating a least one virtual reception channel using a radar antenna and radar system

    公开(公告)号:US11644557B2

    公开(公告)日:2023-05-09

    申请号:US16685585

    申请日:2019-11-15

    Applicant: THALES

    Abstract: A method for creating a virtual reception channel in a radar system includes an antenna possessing two physical reception channels (1r, 2r) spaced apart by a distance d in a direction x, two emission channels (1e, 2e) spaced apart by the same distance d in the same direction x and processing means, the method comprising: dynamically selecting two different waveforms, the waveforms being orthogonal to each other; generating a radar pulse of given central wavelength in each emission channel, each of the emission channels emitting one of the two different waveforms; acquiring with the reception channels echoes due to pulses emitted by the emission channels and reflected by at least one target; compressing the pulses by matched filtering of the echoes acquired by each physical reception channel, this involving correlating them with each of the waveforms generated in the emission channel; and repeating steps a) to c) while randomly changing one of the values of each of the phase codes associated with the generated waveforms until the level of the sidelobes of all the compressed pulses has stabilized; and radar system for implementing such a method.

    Processing method for coherent MIMO radar using DDMA waveforms

    公开(公告)号:US11726171B2

    公开(公告)日:2023-08-15

    申请号:US17084495

    申请日:2020-10-29

    Applicant: THALES

    CPC classification number: G01S7/288 G01S13/582 G01S7/2883 G01S13/913

    Abstract: A method for processing coherent MIMO radar processing DDMA waveforms includes: generating waveforms on transmitters, the waveforms, modulo the pulse repetition frequency, being identical from one transmitter to the next, to within a phase ramp specific to each transmit path; generating, for at least one receiver, a Range-Doppler representation of echoes of transmitted waveforms, where, for each receiver, echoes of a transmitter occupy at least one frequency cell in the Doppler spectrum, each signal band specific to a transmitter, placement of the signal bands in the Doppler spectrum being determined by phase ramp applied to each transmitter, the waveforms generated to leave a portion of Doppler spectrum between two signal bands unoccupied; identifying the transmitter corresponding to each signal band, due to Range-Doppler representation of echoes of transmitted waveforms. The method is suitable for the millimetre band, automotive or aircraft radar, for detection of target relative to the carrier.

    Method for determining parameters of a compression filter and associated multi-channel radar

    公开(公告)号:US10444327B2

    公开(公告)日:2019-10-15

    申请号:US15532080

    申请日:2015-11-10

    Applicant: THALES

    Abstract: A method for determining parameters of a finite impulse response pulse compression filter, implemented by a multi-channel radar comprises: a step Etp10 of transmitting a calibration signal and of acquiring this calibration signal after propagation through the transmission channel, a step Etp20 of injecting the signal acquired, at the input of each of the reception channels, a step Etp30 of measuring the signal at the output of each reception channel, a step Etp40 of calculating the transfer function of the matched filters on the basis of the signals at the output of the reception channels, a step Etp50 of measuring the value of the average power at the output of the various reception channels and of calculating the relative gains between each of the reception channels and a predetermined reception channel on the basis of the measured values of average powers.

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