METHOD FOR MAPPING THE EARTH'S SURFACE BY AN AIRBORNE RADAR STATION WITH ANTENNA ARRAY Russian patent published in 2023 - IPC G01S13/00 

FIELD: radars.

SUBSTANCE: invention can be used in airborne radar stations (ARS) and is intended to solve the problems of mapping the earth's surface. The method is based on the fact that in the process of scanning the antenna array of the earth's surface with a beam, a pulse signal is coherently emitted, signals s₁(t) and s₂(t) reflected from the earth's surface are received by the first and second subarrays of the antenna array. After receiving, the received signals s₁(t) and s₂(t) are gated in range, analogue-to-digital conversion of the received signals s₁(t) and s₂(t) is carried out, coherent accumulation of signals is carried out with the formation of arrays of complex signal samples S₁[n, i] and S₂[n, i], where n is the number of the strobe in range from the total number N of strobes, 1 is the number of the coherently accumulated pulse from the total number I of the accumulated pulses. M phase differences δϕ_m are determined for M accumulated pulses of complex signals S₁[n, i] and S₂[n, i], determined by the difference in distance to the phase centres of the sublattices relative to the observed object on the earth's surface, where m=0… M-1, and M is the number of coherently accumulated pulses reflected from the area of the earth's surface of the irradiated AA of each subarray. Each time choosing M signal pulses S₁[n, i] and S₂[n, i] with a shift of one pulse in each range gate n, the phase difference δϕ_m M of received pulses in all gates of range n of signal S₁[n, i] is compensated K times, M samples of the complex conjugate signal S₂^*[n, i] are formed in each strobe of range n, followed by the multiplication of M samples of the compensated signal and M samples of the complex conjugate signal S₂^*[n, i] in each strobe of range n, and the results of multiplication over M samples is summed K times, each time obtaining the complex amplitude of the resulting signal A_res[nk] in each range strobe n, where k=0… K-1, K=I-M. Then the amplitudes of the radar image C[n,k] are formed in the azimuth-range coordinates. The technical problem solved by the invention is to increase the azimuthal resolution of the radar image generated by the radar.

EFFECT: formation of a narrowed radiation pattern by joint coherent processing of signals received by two subarrays of the ARS antenna array.

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