Thomson-csf

Hubert Joncour

Gerard Auvray

Jean-Claude Guillerot

Bruno Carrara

Jean C Guillerot

Jacques Drevet

Daniel Balduzzi

In a doppler radar, in order to compensate for the speed of moving clutter, one first establishes during a burst of order (i) the phase variation .phi.r.sub.i from one period to the next and which is due to clutter in a given range cell. Then, this phase variation .phi.r.sub.i is memorized and is used during the course of each of the periods of repetition of the next burst to modify the phase of the signal received from the clutter from the same range cell in a maner as to displace its Doppler frequency towards the zero frequencies band, and band which corresponds to the rejection zone of the fixed echoes eliminating filter.

Method and device for compensating for the speed of clutter in a

An apparatus and method for reducing the power of active jamming signals received by the sidelobes of a radar antenna. A known method includes providing a radar with a main antenna and N auxiliary antennas, each antenna being associated with a corresponding processing channel. The signals received by the N antennas are each given a weighting coefficient corresponding to jamming on that channel. The N signals are then combined to form a weighted linear combination which is subtracted from the main channel signal to provide a signal with reduced jamming. The present invention provides apparatus and method for reducing clutter signals (such as fixed echoes and thermal noise) from each of the signals received in the N channels, thus producing very accurate weighting coefficients thereby allowing jamming power to be further reduced. Apparatus and method are provided for carrying out moving target indication (MTI) on all channels, determining the jammed range cells by comparing the main channel signal with the auxiliary channel signals and validating these signals with respect to thermal noise, determining the weighting coefficients from information derived from a given number of jammed range cells (preferably those grouped together at the end of recurrence), forming the weighted linear combination from only those signals which are, in fact, jammed, and subtracting the weighted linear combination from the main channel signal.

Method and device for reducing the power of jamming signals received by

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Palaiseau, France

Hubert Joncour