Abstract: The invention relates to a method for determining the detection threshold of a radar suited to a given environment, characterized in that it comprises at least: a step in which a set of statistical quantities characterizing said environment is selected; a step in which a set of functions is defined, each of said functions giving an intermediate detection threshold that is a function of statistical quantities taken from a subset of said set of statistical quantities; a step of combination of said intermediate detection thresholds, said detection threshold being the result of said combination.

Abstract: A method for determining wave height by means of a radar carried by an aircraft, the method implementing the following steps: a first step of pointing the antenna of the radar; a second step of determining the clutter acquisition plan according to the altitude of the aircraft; a third step of determining, for each clutter zone defined by the acquisition plan, two Doppler parameters PARA1 and PARA2 characterising the zone as a whole; a fourth step of calculating the average values of the parameters PARA1 and PARA2 over all of the zones in question; and a fifth step of estimating the wave height from the averages of the parameters PARA1 and PARA2. The wave height estimated in this way is transmitted to the aircraft and used to determine the conditions for the water landing of the aircraft.

Abstract: Upon each new detection, called pivot detection, by a radar system, the method includes the steps consisting of: grouping together, with the pivot detection, grouped detections, defined as detections that belong to a sweep preceding the sweep of the pivot detection and that have a non-nil probability according to a grouping criterion; filtering the grouped detections so as to keep only detections that are kinematically strictly coherent with the pivot detection, by: initializing a histogram, each dimension of which is a temporal variation of a coordinate measured by the radar system; computing a potential value interval for each coordinate of the pivot detection and each grouped detection; computing a minimum temporal variation and a maximum temporal variation for the or each coordinate from potential value intervals of the pivot detection and each grouped detection; incrementing the set of classes of the histogram whose index along each dimension is located between the computed minimum and maximum temporal v

Abstract: A method includes at least a preliminary step of storing a set of tracking algorithms as a function of types of targets and of environments, each tracking algorithm being a function of a type of target in a given environment; a step of detecting signals backscattered by the targets resulting in primary detections being obtained; the detection step being followed, for each detected target: by a step: of characterizing the detected target into types of target on the basis of the primary detections; and of analysing the environment of the targets in order to determine in which given environment each detected target is located; a step of adapting the tracking to each detected target, the adapting being completed by selecting the tracking algorithm as a function of the type of target to which the target belongs and of the given environment in which it is located.

Abstract: A method for determining wave height by means of a radar carried by an aircraft, the method implementing the following steps: a first step of pointing the antenna of the radar; a second step of determining the clutter acquisition plan according to the altitude of the aircraft; a third step of determining, for each clutter zone defined by the acquisition plan, two Doppler parameters PARA1 and PARA2 characterising the zone as a whole; a fourth step of calculating the average values of the parameters PARA1 and PARA2 over all of the zones in question; and a fifth step of estimating the wave height from the averages of the parameters PARA1 and PARA2. The wave height estimated in this way is transmitted to the aircraft and used to determine the conditions for the water landing of the aircraft.

Abstract: The invention relates to a method for determining the detection threshold of a radar suited to a given environment, characterized in that it comprises at least: a step in which a set of statistical quantities characterizing said environment is selected; a step in which a set of functions is defined, each of said functions giving an intermediate detection threshold that is a function of statistical quantities taken from a subset of said set of statistical quantities; a step of combination of said intermediate detection thresholds, said detection threshold being the result of said combination.

Abstract: Upon each new detection, called pivot detection, by a radar system, the method includes the steps consisting of: grouping together, with the pivot detection, grouped detections, defined as detections that belong to a sweep preceding the sweep of the pivot detection and that have a non-nil probability according to a grouping criterion; filtering the grouped detections so as to keep only detections that are kinematically strictly coherent with the pivot detection, by: initializing a histogram, each dimension of which is a temporal variation of a coordinate measured by the radar system; computing a potential value interval for each coordinate of the pivot detection and each grouped detection; computing a minimum temporal variation and a maximum temporal variation for the or each coordinate from potential value intervals of the pivot detection and each grouped detection; incrementing the set of classes of the histogram whose index along each dimension is located between the computed minimum and maximum temporal v

Abstract: A radar comprises at least one array antenna composed of transmit sub-arrays and of receive sub-arrays, a transmit and receive system and processing means: the distribution of the transmit sub-arrays and receive sub-arrays is symmetric both with respect to a vertical axis and a horizontal axis; at least two transmit sub-arrays symmetric with respect to the vertical axis are the largest possible distance apart; at least two transmit sub-arrays symmetric with respect to the horizontal axis are the largest possible distance apart; at least two receive sub-arrays symmetric with respect to the vertical axis are the largest possible distance apart; at least two receive sub-arrays symmetric with respect to the horizontal axis are the largest possible distance apart; a first coding of the wave transmitted by the transmit sub-arrays carried out by frequency shifting of the ramps between the various transmit sub-arrays; a second coding of the wave transmitted by the transmit sub-arrays carried out by phase modulation f

Abstract: Radar equipped with a transmission antenna array and with a reception antenna array is provided, the measurement of the height h2 is obtained by estimating the frequency of at least one time-dependent amplitude modulation produced on the reception antenna array, the modulation generated by the interference of the signals received directly from the target and the signals received after reflection on the ground, on the basis of the signals transmitted by the transmission antenna array.

Abstract: A method includes at least a preliminary step of storing a set of tracking algorithms as a function of types of targets and of environments, each tracking algorithm being a function of a type of target in a given environment; a step of detecting signals backscattered by the targets resulting in primary detections being obtained; the detection step being followed, for each detected target: by a step: of characterizing the detected target into types of target on the basis of the primary detections; and of analysing the environment of the targets in order to determine in which given environment each detected target is located; a step of adapting the tracking to each detected target, the adapting being completed by selecting the tracking algorithm as a function of the type of target to which the target belongs and of the given environment in which it is located.

Abstract: A detection method for a given mission comprises: a phase of analyzing the environment, wherein phase elements of influence on the sea clutter perceived by the radar are sought and stored in memory; a phase of updating the path to be followed by the carrier depending on the requirements of the mission and the elements of influence issued from the result of the analyzing phase, the path to be followed decreasing the power of the clutter received by the radar when the antenna is pointing towards a search zone liable to contain a target; the phases being repeated throughout the mission.

Abstract: A radar comprises at least one array antenna composed of transmit sub-arrays and of receive sub-arrays, a transmit and receive system and processing means: the distribution of the transmit sub-arrays and receive sub-arrays is symmetric both with respect to a vertical axis and a horizontal axis; at least two transmit sub-arrays symmetric with respect to the vertical axis are the largest possible distance apart; at least two transmit sub-arrays symmetric with respect to the horizontal axis are the largest possible distance apart; at least two receive sub-arrays symmetric with respect to the vertical axis are the largest possible distance apart; at least two receive sub-arrays symmetric with respect to the horizontal axis are the largest possible distance apart; a first coding of the wave transmitted by the transmit sub-arrays carried out by frequency shifting of the ramps between the various transmit sub-arrays; a second coding of the wave transmitted by the transmit sub-arrays carried out by phase modulation f

Abstract: Radar equipped with a transmission antenna array and with a reception antenna array is provided, the measurement of the height h2 is obtained by estimating the frequency of at least one time-dependent amplitude modulation produced on the reception antenna array, the modulation generated by the interference of the signals received directly from the target and the signals received after reflection on the ground, on the basis of the signals transmitted by the transmission antenna array.

Abstract: A detection method for a given mission comprises: a phase of analysing the environment, wherein phase elements of influence on the sea clutter perceived by the radar are sought and stored in memory; a phase of updating the path to be followed by the carrier depending on the requirements of the mission and the elements of influence issued from the result of the analysing phase, the path to be followed decreasing the power of the clutter received by the radar when the antenna is pointing towards a search zone liable to contain a target; the phases being repeated throughout the mission.

Abstract: An input signal amplification system comprises at least two different means of amplifying input signals in order to obtain amplified signals. It also comprises at least one means of summing amplified signals, and dynamic means of activating or deactivating one or more of the amplifying means based on input signals.

Abstract: A radar and method for making a radar undetectable, comprising comprises: on a transmit antenna consisting of N individual subarrays that are non-directional in at least one plane in transmission, each being linked to a waveform generator, generating, for each of the individual subarrays, a waveform so as to make each of the individual subarrays transmit continuous or quasi-continuous signals according to a temporal and periodic pattern by using transmission patterns made up of N different subarrays and which are deduced from one another by an individual delay, on the receive antenna comprising M individual subarrays adapted to pick up the reflected signals obtained from the transmission of the N individual subarrays of the transmit antenna, performing a compression of the received signal in space and in time of the received signals.

Abstract: A method for detecting targets using a mobile radar having a rotary antenna, notably small targets buried in radar clutter, without increasing the number of false detections, includes determining pre-detections during N antenna revolutions, including determining pre-detections revolution by revolution, each pre-detection being stored in a grid of cells centered on the position that the radar occupied at the start of the current revolution, each grid cell corresponding to an azimuth range and a distance range. This step also includes, at the end of each revolution, a step of shifting all the pre-detections stored in the grid during the previous revolutions by the movement undergone by the radar during the last revolution. The method also includes determining detections, a target being detected from the moment that a set of pre-detections stored in the grid has its distances to the radar which constitute a linear progression during the N antenna revolutions.

Abstract: 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.

Abstract: An input signal amplification system comprises at least two different means of amplifying input signals in order to obtain amplified signals. It also comprises at least one means of summing amplified signals, and dynamic means of activating or deactivating one or more of the amplifying means based on input signals.

Abstract: A system and method of radar location comprises radar signal emission means, an emitted pulse of duration T1 and index i starting at instant T2(i); means receiving reflected radar signals; means determining correlation between reconstruction of an emitted pulse and signal received during the time interval between T2(i)+2*T1 and T2(i+1). The means determining a correlation can reconstruct a set, of at least one truncated pulse j of duration T3(j), less than T1, corresponding to the final part of said emitted pulse, said truncated pulses having increasing respective durations, determining at least one first correlated signal j by correlation of said truncated pulse j and signal received during time interval between T2(i)+T1 and T2(i)+T1+T3(j) and determining a second signal, based on first correlated signals j, by copying the time interval, of said correlated signal j, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1), onto the time interval, of said second signal, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1).