Abstract: A Doppler radar with ambiguous electronic scanning, using an active antenna comprising an array of elementary transmission antennas and an array of elementary reception antennas with the same angular opening. The arrays have the same radiation plane. The transmission array is ambiguous with a number of ambiguous lobes within said angular opening of said elementary antennas greater than or equal to 2. The reception array comprises at least one ambiguous lobe within said angular opening. The arrays are arranged so that the product of the transmission and reception radiating patterns only produces a single main beam within the field defined by said angular opening. The coverage of said angular field by said radar obtainable by: forming at the transmission antenna radiating patterns that are focused within a field limited to the transmission ambiguity field; simultaneously forming several reception radiating patterns focused at reception in the ambiguous transmission directions.

Abstract: An imaging method using a doppler radar wherein the pointing direction in transmission (dei) is modified from recurrence to recurrence; each detection block of duration T comprises a periodic repetition of a number C of pointing cycles, each of these cycles comprising a number P of recurrences, the set of these P recurrences covering the De pointing directions (dei) of the set; the order of the pointings is modified in a pseudo-random manner from pointing cycle to pointing cycle during a same detection block so as to create an irregular time interval between two pointings in a same direction; at least one beam is formed in reception on each recurrence in a direction included in the transmission-focused angular domain in the pointing direction corresponding to the recurrence.

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: 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.

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 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 radar attached laterally to airplane fuselage to detect obstacles on a collision course with a portion of the airplane facing the radar, comprises an emission antennal channel and reception antennal channels in the same plane, the form of the wave and field of angular coverage of the radar depending on the velocity of the airplane, the processing means comprising the steps: Establishing in the radar coordinate system a first distance/Doppler map allowing echoes to be separated into distance and Doppler resolution cells in a reception antennal channels; Establishing a second distance/Doppler map of smaller size by selecting a subset of distance/Doppler resolution cells corresponding to the possible positions of targets liable to collide with the wing of the airplane; Establishing new distance/Doppler maps by forming beams computationally from the subsets of distance resolution cells retained for each reception antennal channel; and Temporal integration, in each beam, of successive distance/Doppler maps.

Abstract: The present invention relates to system for detecting obstacles (13, 55, 56, 57) on the ground (15) onboard a carrier (1). The detection system comprises at least two continuous-wave radars (2, 3, 4). The radars (2, 3, 4) are linked to a system (15) for utilizing the detection data arising from the radars (2, 3, 4). The detection system performs localization of an obstacle (13, 55, 56, 57): along a radial axis (12) between a radar (2, 3, 4) and the obstacle (13, 55, 56, 57), by calculating the distance between the radar (2, 3, 4) and the obstacle (13, 55, 56, 57); along a vertical axis (14) with respect to a radar (2, 3, 4), by calculating the elevation of the obstacle (13, 55, 56, 57) using monopulse deviation-measurement processing. The detection system performs localization of an obstacles along a horizontal axis (18) transverse with respect to a sighting axis (11) of a radar (2, 3, 4), by calculating the azimuthal position of the obstacle (13, 55, 56, 57).

Abstract: The present invention relates to system for detecting obstacles (13, 55, 56, 57) on the ground (15) onboard a carrier (1). The detection system comprises at least two continuous-wave radars (2, 3, 4). The radars (2, 3, 4) are linked to a system (15) for utilizing the detection data arising from the radars (2, 3, 4). The detection system performs localization of an obstacle (13, 55, 56, 57): along a radial axis (12) between a radar (2, 3, 4) and the obstacle (13, 55, 56, 57), by calculating the distance between the radar (2, 3, 4) and the obstacle (13, 55, 56, 57); along a vertical axis (14) with respect to a radar (2, 3, 4), by calculating the elevation of the obstacle (13, 55, 56, 57) using monopulse deviation-measurement processing; The detection system performs localization of an obstacles along a horizontal axis (18) transverse with respect to a sighting axis (11) of a radar (2, 3, 4), by calculating the azimuthal position of the obstacle (13, 55, 56, 57).