Proximity radar method and system for a rotary-wing aircraft

Abstract A proximity radar method for a rotary-wing aircraft comprises a sequence of phases T(k) of steps. In a first phase T(1), the electronic computer of the radar system computes unambiguous synthetic patterns on the basis of a first activated interferometric pattern M(1) of N unitary radiating groups. In the following phases T(k) of steps, executed successively in increasing order of k, the electronic computer computes synthetic patterns on the basis of interferometric patterns M(k) of rank k, wherein the N unitary radiating groups of a series deviate simultaneously in terms of azimuth and in terms of elevation as k increases, and establishes maps of rank k of the surroundings in terms of azimuth distance/direction and/or elevation distance/direction cells in which the detected obstacle ambiguities, associated with the network lobes, are removed by virtue of the map(s) provided in the preceding phase or phases. Fig. 5 [Fig. 1] Radiofrequency Eo3 ER2 ER1 ER4 ER5 ER i intermeate frequency 4 1- Lq)72 7 22 16 18 26 28 24 30 G0p Demodulation 54 60 '-5 62 64 GI &-- 32 (ointdoteef) Demodulation 6 34 I 40 42 44 Configuration of groups of radiating elements R/Tx [Fig. 2] 102 Pattern of a unitary 106 Computationally formed 112 114 radiating group Amplitude eam Dirstance 104 Computationally formed beam (oriented to the left) Detection of an Left-hand sector Right-hand sector 112 obstacle 116 ER1 ER4 8 Azimuth Azimuth ER1 ---Uitry. 4 6 radiating Amplitude Direction cosine Direction cosine group 120 121326 Distance 130 --- - - Ambiguous position 128 -4 Real Left-hand sector Right-hand sector position T(2) E2 R Azimuth Azimuth 6 Ampltude Direction cosine Direction cosine 134 146 Dstance 0Ambiguous position - - -- -148,150,152 144 Real Left-hand sector Right-hand sector position T(3>| a a K 129 Azimuth Azimuth .E Direction cosine Direction cosine 18140 12 FIG.2